TW201905957A - Plasma chamber with electrode assembly - Google Patents

Abstract

A processing tool for a plasma process includes a chamber body that has an interior space that provides a plasma chamber and that has a ceiling and an opening on a side opposite the ceiling, a workpiece support to hold a workpiece such that at least a portion of a front surface of the workpiece faces the opening, an actuator to generate relative motion between the chamber body and the workpiece support such that the opening moves laterally across the workpiece, a gas distributor to deliver a processing gas to the plasma chamber, an electrode assembly comprising a plurality of coplanar filaments extending laterally through the plasma chamber between the workpiece support and the ceiling, each of the plurality of filaments including a conductor, and a first RF power source to supply a first RF power to the conductors of the electrode assembly to form a plasma.

Description

Plasma chamber with electrode assembly

The present disclosure relates to a processing tool including a plasma chamber, such as a plasma chamber for depositing a film on a workpiece (such as a semiconductor wafer), etching the workpiece, or processing the workpiece.

Plasma is usually generated using a capacitively coupled plasma (CCP) source or an inductively coupled plasma (ICP) source. A basic CCP source contains two metal electrodes similar to a parallel plate capacitor, which are separated by a small distance in a gaseous environment. One of the two metal electrodes is driven by a fixed frequency radio frequency (RF) power supply, while the other electrode is connected to RF ground, creating an RF electric field between the two electrodes. The generated electric field ionizes gas atoms and releases electrons. The electrons in the gas are accelerated by the RF electric field, and the plasma is directly or indirectly ionized by the collision.

A basic ICP source usually contains a spiral or coiled conductor. When an RF current flows through a conductor, an RF magnetic field is formed around the conductor. The RF magnetic field is accompanied by an RF electric field, which ionizes gas atoms and generates a plasma.

Plasma of various processing gases is widely used in the manufacture of integrated circuits. For example, plasma can be used for thin film deposition, etching and surface treatment.

Atomic layer deposition (ALD) is a thin film deposition technology based on the sequential use of gas phase chemical processes. Some ALD processes use plasma to provide the necessary activation energy for chemical reactions. Plasma-enhanced ALD processes can be performed at lower temperatures than non-plasma-enhanced (eg, "hot") ALD processes.

In one aspect, a processing tool for plasma processing includes a chamber body, a workpiece support, an actuator, a gas distributor, an electrode assembly, and a first RF power source. The chamber body has an internal space, and the interior The space provides a plasma chamber, the chamber body having a top plate and an opening on a side opposite to the top plate, the workpiece support holds the workpiece such that at least a portion of a front surface of the workpiece faces the opening, and the actuator is in the Relative motion is generated between the chamber body and the workpiece support, such that the opening moves laterally across the workpiece, the gas distributor delivers process gas to the plasma chamber, and the electrode assembly contains a plurality of coplanar wires (Coplanar filaments), the plurality of coplanar filaments extend laterally through the plasma cavity between the workpiece support and the top plate, each of the plurality of filaments includes a conductor, and the first RF power source is directed toward The conductors of the electrode assembly provide first RF power to form a plasma.

Implementations may include one or more of the following features.

The workpiece support is rotatable about a rotation axis, and the actuator can rotate the workpiece support, so that the rotation of the support carries the workpiece across the opening.

A plurality of coplanar wires may extend across the wedge-shaped area. The workpiece may fit completely within the wedge-shaped region so that the entire front surface of the workpiece is exposed to the plasma during operation. The workpiece may be larger than the wedge-shaped area so that the wedge-shaped portion of the front surface of the workpiece is exposed to the plasma during operation. The opening may be wedge-shaped.

The plurality of coplanar wires may be linear wires, and different wires may have different lengths to define a wedge-shaped region. The plurality of coplanar wires may extend in parallel. The plurality of coplanar filaments may be evenly spaced. Different wires can be oriented at different angles. The plurality of coplanar filaments may be oriented such that the plasma density generated in the wedge region is lower at the apex of the wedge region than at the base of the wedge region. The plurality of coplanar filaments may be oriented to have a longitudinal axis at a non-zero angle with respect to a direction of motion of a portion of the substrate below the opening. The non-zero angle may be greater than 10 °.

The spacing between the coplanar filaments may be sufficient to avoid pinch of the plasma region between the area above and below the electrode assembly within the chamber. The bottom of the chamber may be open. The tool may include a top electrode on the top plate of the chamber.

The ends of the conductors of the plurality of coplanar wires can be connected to the first RF power source through a recursive RF feed structure. Opposite ends of the conductors of the plurality of coplanar wires can be connected to a common bus. The bus can be connected to the first RF power source at two opposing locations.

The first multiple conductors of the plurality of coplanar wires may be connected to a first RF power source, and the second multiple conductors of the plurality of coplanar wires may be floating or grounded. The first ends of the conductors of the plurality of coplanar wires can be coupled to the first RF power source through a common bus. The conductors of the first group and the conductors of the second group may be arranged to alternate in a direction perpendicular to the longitudinal axis of the wire.

In another aspect, the plasma reactor includes a chamber body, a gas distributor, a workpiece support, an electrode assembly, a first RF power source, and a dielectric bottom plate. The chamber body has an internal space that provides a plasma. Chamber, the gas distributor delivers processing gas to the plasma chamber, the workpiece support holds the workpiece, the electrode assembly includes a plurality of conductors, and the plurality of conductors communicate with the workpiece support in a parallel coplanar array Spaced apart and extending laterally across the workpiece support, the first RF power source provides first RF power to the electrode assembly, the dielectric substrate is between the electrode assembly and the workpiece support, and the dielectric substrate is at An RF window is provided between the electrode assembly and the plasma chamber.

Implementations may include one or more of the following features.

A plurality of conductors may be positioned between the dielectric top plate and the dielectric window. The dielectric top plate may be a ceramic body, and the dielectric bottom plate may be quartz or silicon nitride.

The bottom surface of the bottom plate may have a plurality of parallel grooves, and a plurality of parallel coplanar conductors may be positioned in the plurality of parallel grooves. The plurality of wires may be positioned in the plurality of slots. Each wire may include a conductor and a non-metallic shell surrounding the conductor. The shell may form a conduit, and the conductor may be suspended in and extend through the conduit. The conductor may include a hollow conduit.

A plurality of conductors may be coated on the dielectric top plate. A plurality of conductors may be embedded in the dielectric top plate.

The plurality of conductors may be evenly spaced. The interval between the workpiece support and the plurality of conductors may be 2 mm to 50 cm.

The plurality of conductors may include a first multiple conductor and a second multiple conductor, the second multiple conductors being arranged in an alternating pattern with the first multiple conductor. The RF power supply may be configured to apply a first RF input signal to a first multiple conductor and a second RF input signal to a second multiple conductor. The RF power source may be configured to generate the first RF signal and the second RF signal at the same frequency. The RF power supply may be configured to generate a first RF signal and a second RF signal such that a phase difference between the first RF signal and the second RF signal is 180 °. The RF power supply may be configured to provide an adjustable phase difference between the first RF signal and the second RF signal.

The plurality of conductors may have a plurality of first ends on a first side of the plasma chamber and a plurality of second ends on an opposite second side of the plasma chamber. The RF power supply may be configured to apply a first RF input signal to a first end of the first multi-conductor and a second RF input signal to a second end of the second multi-conductor. The second end of the first multiple conductor may be floating, and the first end of the second multiple conductor may be floating. A first end of the first multiple conductor may be connected to a first common bus, and a second end of the second multiple conductor may be connected to a second common bus. The first multifilament can be grounded, and the first end of the second multifilament can be grounded.

A first end of the first multiple conductor may be connected to a first common bus outside the plasma chamber on a first side of the chamber, and a second end of the second multiple conductor may be connected to a first A second common bus outside the plasma chamber on both sides. The second end of the first multiple conductor may be connected to a third common bus outside the plasma chamber on the second side of the chamber, and the first end of the second multiple conductor may be connected to the first A fourth common bus outside the plasma chamber on the side.

In another aspect, the plasma reactor includes a chamber body, a gas distributor, a pump, a workpiece support, an electrode assembly in the chamber, a first bus and a second bus, an RF power source, and at least one RF switch. The main body of the chamber has an internal space that provides a plasma chamber, the gas distributor delivers processing gas to the plasma chamber, the pump is coupled to the plasma chamber to evacuate the chamber, and the workpiece support holds Workpiece, the electrode assembly in the chamber contains a plurality of wires, the plurality of wires extending laterally through the plasma chamber between the top plate of the plasma chamber and the workpiece support, each wire containing a cylindrical insulation A conductor surrounded by a shell, wherein the plurality of filaments includes a first multiple filament and a second multiple filament, the second multiple filament and the first multiple filament are arranged in an alternating pattern, and the first bus is coupled to the A first multiple wire, the second bus is coupled to the second multiple wire, the RF power source applies an RF signal to the electrode assembly in the chamber, and the at least one RF switch is configured to controllably connect the first bus to the following One of each is electrically coupled and decoupled: i) , Ii) RF power supply, or iii) the second bus.

Implementations may include one or more of the following features.

The at least one RF switch may include a plurality of RF switches connected in parallel between the first bus and one of: i) a ground, ii) an RF power source, or iii) a second bus.

At least one RF switch may be configured to controllably electrically couple and decouple the first bus and the second bus. The at least one RF switch may include a plurality of switches connected in parallel between different pairs of positions on the first bus and the second bus to controllably electrically couple and decouple the first bus and the second bus.

The at least one RF switch may include a first switch configured to controllably couple and decouple the first bus to ground electrically and include at least one second RF switch configured to The second bus is controllably electrically coupled and decoupled from ground. The at least one RF switch may include a first plurality of switches connected in parallel between different positions on the first bus and ground, and the at least one second switch may include a parallel connection between different positions on the second bus and ground A second plurality of switches connected. Different positions on the first bus may include opposite ends of the first bus, and different positions on the second bus may include opposite ends of the second bus.

The at least one RF switch may include a first plurality of switches connected in parallel between different positions on the first bus and the RF power source, and the at least one second switch may include different positions on the second bus and the RF power source. A second plurality of switches connected in parallel between each other. Different positions on the first bus may include opposite ends of the first bus, and different positions on the second bus may include opposite ends of the second bus. The at least one RF switch may include a first plurality of switches connected in parallel between the different positions on the first bus and the RF power source, and the at least one second switch may include different positions on the second bus and the ground. A second plurality of switches connected in parallel between each other. Different positions on the first bus may include opposite ends of the first bus, and different positions on the second bus may include opposite ends of the second bus.

The at least one RF switch includes a first switch and includes at least one second switch. The first switch is configured to controllably couple and decouple the first bus from the RF power source. The at least one second switch is configured to controllably. The second bus is electrically coupled and decoupled from the RF power source.

Certain implementations may include a third bus and a fourth bus, the third bus being coupled to a first multiple wire, the fourth bus being coupled to a second multiple wire, wherein the plurality of wires have a plurality of first ends and a plurality of wires Second ends, and the first end of each corresponding wire is closer to the first side wall of the plasma chamber than the second end of the corresponding wire, and the first bus is coupled to the first multiple wire First end, the second bus is coupled to the first ends of the second multifilament, the third bus is coupled to the second ends of the first multifilament, and the fourth bus is coupled Connected to the second ends of the second multifilament.

The at least one RF switch may be configured to controllably couple and electrically couple the first bus to the second bus, and may include at least one second RF switch configured to controllably connect the first bus to the first bus. The three buses are electrically coupled and decoupled from the fourth bus.

The at least one RF switch may include a first switch configured to controllably couple and decouple the first bus to ground electrically, and may include at least one second RF switch, the second RF switch being The configuration controllably couples and decouples the third bus from ground.

The RF source may be coupled to the fourth bus through a first tap and to the second bus through a second tap.

Certain implementations may include at least one third RF switch configured to controllably couple and decouple the third bus to ground, and include at least one fourth RF switch configured to control The ground electrically couples and decouples the fourth bus from the ground. The at least one RF switch may include a first switch, the first switch being configured to controllably couple and decouple the first bus to ground, and includes at least one second RF switch, at least one third RF switch, The second RF switch is configured to controllably couple and decouple the second bus from the RF source, and the third RF switch is configured to controllably couple and decouple the third bus from the ground. It includes at least one fourth RF switch configured to controllably electrically couple and decouple the fourth bus from the RF source.

The at least one RF switch includes a first switch configured to controllably electrically couple and decouple the first bus from the RF source, and includes at least one second RF switch and at least one third RF switch. The second RF switch is configured to controllably couple and decouple the second bus from the RF source, and the third RF switch is configured to controlly couple and decouple the third bus from the RF source. And includes at least one fourth RF switch configured to controllably electrically couple and decouple the fourth bus from the RF source.

In another aspect, the plasma reactor includes a chamber body, a gas distributor, a pump, a workpiece support, an electrode assembly in the chamber, a bus, an RF power source, and a plurality of RF switches. The chamber body has an internal space. The internal space provides a plasma chamber, the gas distributor delivers processing gas to the plasma chamber, the pump is coupled to the plasma chamber to evacuate the chamber, the workpiece support holds the workpiece, and the electrode assembly in the chamber Containing a plurality of wires that extend laterally through the plasma chamber between the top plate of the plasma chamber and the workpiece support, each wire containing a conductor surrounded by a cylindrical insulating shell, the bus Outside the chamber and coupled to the opposite ends of the plurality of wires, the RF power supply applies an RF signal to the electrode assembly in the chamber. The plurality of RF switches are configured to controllably control a plurality of different positions on the bus to the following One of each is electrically coupled and decoupled: i) ground or ii) the RF power source.

Certain implementations may have one or more of the following advantages. Can improve plasma uniformity. Can improve the repeatability of the plasma process. Can reduce metal pollution. Can reduce particle generation. Can reduce plasma charging damage. It can maintain the uniformity of the plasma under different process operating conditions. Can improve plasma power coupling efficiency. For workpieces of a given size, the size of the plasma area can be reduced. Can improve the plasma process yield. The workpiece can be continuously carried through multiple chambers while held on a support. The effect of relative speed during plasma exposure can be compensated, thus improving uniformity within the wafer. By switching, the influence of local unevenness in the plasma region can be reduced, so the uniformity within the wafer can be improved. Provides low impedance RF ground. Can reduce particle generation. Can reduce plasma charging damage. It can maintain the uniformity of the plasma under different process operating conditions. Can improve plasma power coupling efficiency. A grounded top electrode that can be integrated with the gas distribution nozzle is used to introduce the gas in a uniform manner without generating unnecessary gas decomposition in the nozzle hole.

In a conventional plasma reactor, the workpiece remains stationary within the reaction chamber. A plasma area is created above the stationary workpiece, which then processes the surface of the workpiece. However, certain plasma processing applications may benefit from moving the workpiece through the plasma area, ie, relative motion between the plasma area and the workpiece. In addition, for some tools, the substrate is moved between different chambers to perform a series of processing steps.

One way to achieve relative motion between the workpiece and the plasma area is by placing the workpiece on a workpiece support that moves along a linear path, such as a conveyor belt. In such a configuration, the workpiece can be single-passed in one direction through the plasma area and exited on the other side of the chamber. This may be advantageous for certain sequential processes where the workpiece travels through multiple chambers of different types as part of the manufacturing process.

Another method of achieving relative motion between the workpiece and the plasma area is by placing the workpiece on a rotating workpiece support. Rotating the workpiece support can pass through the plasma area multiple times without changing the direction of travel, which can increase throughput because the workpiece support does not need to continuously change its direction of travel. However, if the support rotates, different areas of the workpiece may move at different speeds relative to the area plasma.

In traditional CCP sources, plasma uniformity is usually determined by electrode size and distance between electrodes, as well as gas pressure, gas composition, and applied RF power. At higher radio frequencies, additional effects may become significant or even dominate non-uniformity due to the presence of standing waves or skin effects. At higher frequencies and plasma densities, this additional effect becomes more pronounced.

The uniformity of the plasma in a traditional ICP source is usually determined by the configuration of the ICP coil, including its size, geometry, distance to the workpiece, and associated RF window location, as well as gas pressure, gas composition, and power. In the case of multiple coils or coil segments, the current or power distribution and its relative phase may also be significant factors if driven at the same frequency. Due to the skin effect, power deposition tends to occur within a few centimeters below or near the ICP coil, and this localized power deposition often results in process inhomogeneities that reflect the geometry of the coil. This plasma non-uniformity results in a potential difference on the workpiece, which may also cause damage to the plasma charge (such as a dielectric gate dielectric crack).

Large diffusion distances are usually required to improve the uniformity of the ICP source. However, due to low power coupling, traditional ICP sources with thick RF windows are usually inefficient at high pressures, which results in high drive currents and high resistance power losses. In contrast, the electrode assembly in the chamber need not have an RF window, but only a cylindrical case. This can provide better power coupling and higher efficiency.

In a plasma chamber with a moving workpiece support, the moving workpiece support may be DC-grounded by, for example, a rotating mercury coupling, a brush, or a slip ring. However, moving workpiece supports may not be adequately grounded at RF. The RF ground path should have a much lower impedance than the plasma to make it an adequate RF ground. The lack of an adequate RF ground path may make it difficult to control the ion energy at the workpiece and reduce process repeatability.

Therefore, there is a need for a plasma source having the following properties: it can efficiently produce a uniform plasma with the required characteristics (plasma density, electron temperature, ion energy, dissociation, etc.) on the size of the workpiece; it can uniformly adjust the operating window Properties (such as pressure, power, gas composition); it has stable and repeatable electrical properties even when the workpiece moves; and it does not produce excessive metal contaminants or particles. An electrode assembly in a chamber may better provide one or more of these properties.

FIG. 1 is a schematic side view of an example of a processing tool. The processing tool 100 has a chamber body 102 surrounding the internal space 104. The internal space 104 may be cylindrical, such as for receiving a circular workpiece support. At least part of the internal space is used as a plasma chamber or a plasma reactor. The chamber body 102 has a support 106 for providing mechanical support for various components in the internal space 104. For example, the support 106 may provide support for the top electrode 108. The top electrode may be suspended in the internal space 104 and may be spaced from the top plate, abut the top plate, or form a part of the top plate. Certain portions of the sidewall of the chamber body 102 may be grounded independently of the top electrode 108.

The gas distributor 110 is located near the top plate of the plasma reactor section of the processing tool 100. In some implementations, the gas distributor 110 is integrated with the top electrode 108 into a single component. The gas distributor 110 is connected to a gas supply 112. The gas supply 112 delivers one or more process gases to the gas distributor 110, and the composition of the process gas may depend on the process to be performed, such as deposition or etching.

A vacuum pump 113 is coupled to the internal space 104 to evacuate the processing tool. For some processes, the chamber operates in the Torr range, and the gas distributor 110 supplies argon, nitrogen, oxygen, and / or other gases.

A workpiece support 114 for supporting the workpiece 115 is positioned in the processing tool 100. The workpiece support 114 has a workpiece support surface 114 a facing the top plate of the processing tool 100. For example, the workpiece support surface 114 a may face the top electrode 108. The workpiece support 114 is operable to rotate about a shaft 150. For example, the actuator 152 may rotate the drive shaft 154 to rotate the workpiece support 114. In some implementations, the shaft 150 coincides with the center of the workpiece support 114.

In some implementations, the workpiece support 114 includes a workpiece support electrode 116 inside the workpiece support 114. In some implementations, the workpiece support electrode 116 may be grounded or connected to a grounded impedance or circuit. In some implementations, the RF bias power generator 142 is coupled to the workpiece support electrode 116 via an impedance match 144. The work support electrode 116 may additionally include an electrostatic chuck, and a work bias voltage supply 118 may be connected to the work support electrode 116. The RF bias power generator 142 may be used to generate a plasma, control an electrode voltage or a sheath voltage, or control the ion energy of the plasma.

In addition, the workpiece support 114 may have an internal channel 119 for heating or cooling the workpiece 115. In some implementations, an embedded resistance heater may be disposed inside the internal channel 119.

In some implementations, the workpiece support 114 is heated by radiation, convection, or conduction from a heating element located in the bottom interior space 133.

The intra-cavity electrode assembly 120 is positioned in an internal space 104 between the top electrode 108 and the workpiece support 114. This electrode assembly 120 includes one or more coplanar wires 300 that extend laterally in the chamber and above the support surface 114 a of the workpiece support 114. At least a portion of the coplanar wire of the electrode assembly 120 above the workpiece support 114 extends parallel to the support surface 114a. Although the left side of FIG. 1 shows that the wire 300 is parallel to the moving direction of the workpiece 115 (in and out of the page), the wire 300 may be at a non-zero angle with respect to the moving direction, such as substantially perpendicular to the moving direction.

A top gap 130 is formed between the top electrode 108 and the electrode assembly 120 in the chamber. A bottom gap 132 is formed between the workpiece support 114 and the electrode assembly 120 in the chamber.

The internal space 104 can be divided into one or more regions 101a, 101b by an obstacle, and at least one of these regions serves as a plasma chamber. The barrier defines one or more openings 123 above the workpiece support. In some implementations, the electrode assembly 120 is positioned within the opening 123. In some implementations, the electrode assembly is placed over the opening 123. In some implementations, the barrier is integrally formed from the support 106 and an opening 123 is formed on the support 106. In some implementations, the opening 123 formed on the support 106 is configured to support the electrode assembly 120.

The electrode assembly 120 is driven by an RF power source 122. The RF power source 122 may power one or more coplanar wires of the electrode assembly 120 at a frequency of 1 MHz to more than 300 MHz. For some processes, the RF power source 120 provides a total RF power of 100W to greater than 2kW at a frequency of 60MHz.

In some implementations, the bottom gap 132 may need to be selected so that free radicals, ions, or electrons generated by the plasma interact with the workpiece surface. The choice of clearance depends on the application and the method of operation. For some applications where free radical flux (but very low ion / electron flux) needs to be delivered to the surface of the workpiece, operation at larger gaps and / or higher pressures can be selected. For other applications where free radical flux and a large amount of plasma ion / electron flux need to be delivered to the surface of the workpiece, operations with smaller gaps and / or lower pressures can be selected. For example, in some low temperature plasma enhanced ALD processes, free radicals of the processing gas are necessary for the deposition or processing of the ALD film. Free radicals are atoms or molecules with unpaired valence electrons. Free radicals are usually highly chemically active against other substances. The reaction of free radicals with other chemicals often plays an important role in film deposition. However, free radicals are usually short-lived due to their high chemical activity and therefore cannot travel very far during their life cycle. Placing a radical source (ie, the electrode assembly 120 in the chamber as a plasma source) near the surface of the workpiece 115 can increase the supply of radicals to the surface to improve the deposition process.

The life cycle of free radicals usually depends on the pressure of the surrounding environment. Therefore, the height of the bottom gap 132 that provides a satisfactory concentration of free radicals may vary depending on the expected chamber pressure during operation. In some implementations, if the chamber is operated at a pressure in the range of 1 to 10 Torr, the bottom gap 132 is less than 1 cm. In other (relatively) lower temperature plasma enhanced ALD processes, exposure to plasma ion flux (and accompanying electron flux) and free radical flux may be necessary to deposit and process ALD films. In some implementations, if the chamber is operated at a pressure in the range of 1-10 Torr, the bottom gap 132 is less than 0.5 cm. Due to the lower volume recombination rate relative to distance, lower operating pressures can be operated with larger gaps. In other applications (such as etching), lower operating pressures (less than 100mTorr) are often used and gaps can be increased.

In such applications where the bottom gap 132 is small, the plasma generated by the electrode assembly 120 may have significant non-uniformity between the filaments, which may be detrimental to the uniformity of processing of the workpiece. By moving the workpiece through a plasma with spatial inhomogeneity, it can be mitigated by the time-averaging effect (that is, after a single pass of the plasma, the cumulative amount of plasma received in any given area of the workpiece is substantially similar) Influence of Plasma Space Inhomogeneity on Process.

The top gap can be chosen large enough for the plasma to develop between the chamber electrode assembly and the top electrode (or the top of the chamber). In some implementations, if the chamber is operated at a pressure in the range of 1-10 Torr, the top gap 130 may be between 0.5-2 cm, such as 1.25 cm.

The top electrode 108 may be configured in various ways. In some implementations, the top electrode is connected to RF ground 140. In some implementations, the top electrode is electrically isolated ("floating"). In some implementations, the top electrode 108 is biased to a bias voltage. The bias voltage can be used to control the characteristics of the generated plasma (including ion energy). In some implementations, the top electrode 108 is driven with an RF signal. For example, driving the top electrode 108 relative to a workpiece support electrode 116 that has been grounded may increase the plasma potential at the workpiece 115. Increasing the plasma potential can increase the ion energy to the desired value.

The top electrode 108 may be formed of different process compatible materials. Various criteria for process computability include the material's resistance to process gas etching and resistance to sputtering from ion impact. In addition, in the case where the material amount is etched, the process-compatible material preferentially forms volatile or gaseous compounds (which can be evacuated by the vacuum pump 113), and does not form particles that may contaminate the workpiece 115. Therefore, in some implementations, the top electrode is made of silicon. In some implementations, the top electrode is made of silicon carbide.

In some implementations, the top electrode 108 may be omitted. In such an implementation, the RF ground path may be provided by a workpiece support electrode, a subset of coplanar wires of the electrode assembly 120, or by the chamber wall or other ground-referenced surface in communication with the plasma. provide.

In some implementations, the fluid supply 146 circulates fluid through channels in the electrode assembly 120 within the chamber. In some implementations, the heat exchanger 148 is coupled to the fluid supply 146 to remove heat or supply heat to the fluid.

Depending on the chamber configuration and the supplied process gas, the plasma reactor in the processing tool 100 may provide ALD equipment, etching equipment, plasma processing equipment, plasma enhanced chemical vapor deposition equipment, plasma doping equipment, or plasma Surface cleaning equipment.

FIG. 2A is a schematic top view of an example of a processing tool 200. The processing tool 200 is similar to the processing tool 100 except as described. The processing tool 200 has a cylindrical chamber body 202, an internal space 204 having a cylindrical shape, a support 206, an electrode assembly 220, and a precursor station 260. The support 206 is located in the center of the processing tool 200, and a plurality of radial partitions 270 are formed to divide the internal space 204 into multiple processing regions. For example, multiple processing regions may be configured to have a wedge-shaped shape (such as a circular cross-section or an equilateral triangle) or may be cut away at the vertices. The processing area may be configured in various ways to achieve various functions required for the operation of the processing tool 200.

The precursor processing area is configured to process the workpiece 115 with one or more precursors, such as those used in an ALD process. For example, the first precursor station 260a positioned within the precursor processing area 280a may be configured to flow or pump the chemical precursor A such that the workpiece 115 is processed when the workpiece 115 moves under the precursor station 260a. Then, the precursor station 260a may process the workpiece 115 with the chemical precursor B, and prepare a surface of the workpiece 115, such as a surface treatment for an ALD film forming plasma.

In some implementations, the precursor processing region 280 includes a plurality of sub-regions having respective precursor stations 260 for respective chemical precursors. In some implementations, the secondary regions are arranged sequentially along the path of the workpiece 115. In some implementations, movement of the workpiece 115 is stopped during the precursor surface treatment. In some implementations, the workpiece 115 continuously moves through the precursor processing area 280.

The gas isolation region 281 is configured to provide spatial isolation of individual processing environments of a plurality of processing regions, such as a first processing region and a second processing region. The gas isolation zone 281 may include a first pumping zone 282, a purge zone 283, and a second pumping zone 284, each zone being separated by a respective radial partition 270. In conventional systems, the isolation of the processing environment may be provided by an air-tight seal between the first and second processing areas. However, it may not be practical to provide such a seal due to the rotating workpiece support 114. Conversely, an isolation level sufficient for a plasma processing application such as ALD can be provided by inserting a gas isolation region 281 between the first and second processing regions.

Referring to FIG. 2B, a cross-sectional view of a portion of the processing tool 200 along a section line B is shown. During operation, the first pumping area 282 adjacent to the first processing area (such as the precursor processing area 280a) generates a negative pressure difference relative to the first processing area. For example, a vacuum pump can be used to generate a negative pressure differential. This negative pressure difference causes the process gas leaking from the first processing region to be pumped out through the first pumping region 282 as shown by the arrow. Similarly, the second pumping zone 284 adjacent to the second processing zone provides a negative pressure differential with respect to the second processing zone, such as the plasma processing zone 285a.

A purge zone 283 between the first pumping zone 282 and the second pumping zone 284 supplies purge gas. Examples of the purge gas include inert gases such as argon and nitrogen. Due to the negative pressure difference generated by the first and second pumping zones, the purge gas supplied from the purge zone 283 is pumped to the first and second pumping zones as shown by the arrows. The presence of the purge gas can prevent the corresponding processing gases of the first and second processing areas from being mixed with each other. Mixing the corresponding processing gases of the first and second processing areas with each other may cause unnecessary chemical reactions, resulting in unnecessary deposition, etching or Residues are produced.

The first gap height H ₁ provides a gap between the radial spacer 270 and the workpiece support 114. The first gap height may be determined based on providing sufficient clearance for the workpiece 115 to pass while reducing the leakage of processing gas into the pumping zones 282 and 284. For example, the first gap height may be in the range of 2-4 mm, such as 3 mm.

Referring back to FIG. 2A, the plasma processing area 285 is configured to process the workpiece 115 with a plasma. For example, the electrode assembly 220 a located in the plasma processing region 285 a may generate a plasma for processing a surface of the workpiece 115. The precursor-treated surface of the workpiece 115 that has moved through the gas isolation zone 281 is treated with a plasma generated by the electrode assembly 220a. In some implementations, the plasma treatment completes a single atomic layer deposition cycle of the first ALD film.

In some implementations, the electrode assembly 220 is formed in a rectangle as shown. In some implementations, the electrode assembly 220 is formed in a wedge shape.

Referring back to FIG. 2B, in some implementations, a process gas for the plasma processing region 285 is provided through a gas inlet 210 formed adjacent the electrode assembly 220. Specifically, the gas inlet 210 may be provided at an edge of the gas isolation region 281 adjacent to the plasma processing region 285a. For example, a channel may be formed between one of the separators 270 and the outer wall 221 of the electrode assembly 220a.

The second gap height H ₂ provides a gap between the electrode assembly 220 and the workpiece support 114. The second gap height may be determined based on providing sufficient clearance for the workpiece 115 to pass through and the processing gas to the inner area of the electrode assembly 220 while reducing leakage of processing gas into the pumping zones 282 and 284. For example, the second gap height may be in the range of 1-3 mm, such as 2 mm. In some implementations, a gas inlet is formed on the entry side of the workpiece 115. In some implementations, the gas inlet is formed toward a radially outer edge of the electrode assembly, which is near the chamber wall 202. In some implementations, the gas inlet is formed toward the center of the workpiece support 114, such as near the shaft 150.

In some implementations, the top electrode 208 is formed as part of or supported by the electrode assembly 220a. For example, the top electrode 208 may be supported by the top plate 221a.

Referring to FIG. 2C, a cross-sectional view of a portion of the processing tool 200 along a section line C is shown. In some implementations, as shown, the support 206 is configured to provide mechanical support for the electrode assemblies 220a and 220b.

In some implementations, the processing tool 200 includes a second precursor processing region 280b and a second plasma processing region 285b. Regions 280b and 285b may be configured to deposit a second ALD film. In some implementations, the second ALD film is the same as the first ALD film deposited in regions 280a and 285a. Such an implementation can improve the deposition speed of a single ALD film. In some implementations, the second ALD film is different from the first ALD. In such an implementation, two different ALD films may be deposited in an alternating manner. In general, the processing tool 200 may be configured to deposit two, three, four, or more types of ALD films.

In general, the workpiece 115 may pass a single pass or may pass through the processing area multiple times. For example, the direction of rotation may be alternated to pass through a specific processing area multiple times.

In general, the processing areas can be arranged in any order. For example, the precursor processing region may be followed by two different plasma processing regions having the same or different plasma characteristics.

With respect to FIGS. 1 or 2A-2C, the electrode assembly 120 or 220 includes one or more coplanar wires 300 that extend laterally in the chamber and above the support surface of the workpiece support. At least a portion of the coplanar wire of the electrode assembly above the workpiece support extends parallel to the support surface. The wire 300 may be at a non-zero angle with respect to the direction of motion, such as substantially perpendicular to the direction of motion.

The electrode assembly may include a side wall 221 surrounding an area of the electrode plasma chamber. The sidewall can be formed from a process compatible material, such as quartz. In some implementations, the wires project sideways laterally. In some implementations, the end of the wire 300 extends out of the top plate of the electrode assembly and turns to provide a portion parallel to the support surface of the workpiece (see Figure 2C).

3A-C are schematic diagrams of various examples of wires of an electrode assembly in a chamber. Referring to FIG. 3A, a wire 300 of an electrode assembly 120 in a chamber is shown. The wire 300 includes a conductor 310 and a cylindrical shell 320 that surrounds the conductor 310 and extends along the conductor 310. The channel 330 is formed by a gap between the conductor 310 and the cylindrical case 320. The cylindrical case 320 is formed of a non-metallic material compatible with the process. In some implementations, the cylindrical shell is semi-conductive. In some implementations, the cylindrical shell is insulated.

The conductor 310 may be formed of various materials. In some implementations, the conductor 310 is a solid wire, such as a single solid wire with a diameter of 0.063 ". Alternatively, the conductor 310 can be provided by a plurality of stranded wires. In some implementations, the conductor contains three parallel 0.032" stranded wires . Multiple stranded wires can reduce RF power loss through skin effect. In some implementations, the conductor 310 is formed of a Litz wire, which can further reduce the skin effect.

Using a material having a high conductivity (e.g., greater than ¹⁰⁷ Siemens / meter (Siemen / m)), which can reduce the resistance power loss. In some implementations, the conductor 310 is made of copper or a copper alloy. In some implementations, the conductor is made of aluminum.

Unnecessary material sputtering or etching can lead to process contamination or particle formation. Whether the electrode assembly 120 in the chamber is used as a CCP or as an ICP source, unnecessary sputtering or etching may occur. Unnecessary sputtering or etching may be caused by excessive ion energy on the electrode surface. When operating as a CCP source, an oscillating electric field around a cylindrical shell is required to drive the plasma discharge. Because the sputtering energy threshold of all known materials is below the corresponding minimum operating voltage of the CCP source, this oscillation causes sputtering or etching of the material. When operating as an ICP source, the capacitive coupling of the wire 300 and the plasma generates an oscillating electric field at a nearby surface, which also causes sputtering of the material. By using a process compatible material on the outer surface of the wire 300 exposed to the internal space 104 (such as the cylindrical shell 320), problems caused by unnecessary material sputtering or etching can be reduced.

In some implementations, the cylindrical shell 320 is formed of a process-compatible material, such as silicon (such as high-resistivity silicon), an oxide material, a nitride material, a carbide material, a ceramic material, or a combination thereof. Examples of the oxide material include silicon dioxide (eg, silica, quartz) and aluminum oxide (eg, sapphire). Examples of the carbide material include silicon carbide. For some chemical environments, including those containing fluorine or fluorocarbons, ceramic materials or sapphire may be required. In chemical environments containing ammonia, dichlorosilane, nitrogen, and oxygen, silicon, silicon carbide, or quartz may be required.

In some implementations, the cylindrical shell 320 has a thickness of 0.1 mm to 3 mm, such as 2 mm.

In some implementations, a fluid is provided in the channel 330. In some implementations, the fluid is a non-oxidizing gas to purify oxygen to mitigate oxidation of the conductor 310. Examples of non-oxidizing gases are nitrogen and argon. In some implementations, a non-oxidizing gas is continuously flowed through the channel 330, such as by a fluid supply 146, to remove residual oxygen or water vapor.

Heating the conductor 310 may make the conductor easier to oxidize. The fluid may provide cooling for the conductor 310 that may be heated from the supplied RF power. In some implementations, fluid is circulated through the channel 330, such as by a fluid supply 146, to provide forced convection temperature control, such as cooling or heating.

In some implementations, the fluid can be near or above atmospheric pressure to prevent fluid breakdown. For example, by providing a fluid pressure above 100 Torr, gas decomposition in the tube or unnecessary plasma formation can be prevented.

Referring to FIG. 3B, in some implementations of the wire 300, the conductor 310 has a coating 320. In some implementations, the coating 320 is an oxide of a material forming the conductor (such as alumina on an aluminum conductor). In some implementations, the coating 320 is silicon dioxide. In some implementations, the coating 320 is formed in situ in the plasma reactor of the processing tool 100, for example, a silicon dioxide coating is formed by the reaction of silane, hydrogen, and oxygen. Because in-situ coatings can be replenished during etching or sputtering, in-situ coatings can be advantageous. The in-situ coating may have a thickness ranging from 100 nm to 10 μm.

Referring to FIG. 3C, in some implementations of the wire 300, the conductor 310 is hollow, and a hollow channel 340 is formed inside the conductor 310. In some implementations, as described in FIG. 3A, the hollow channel 340 can carry a fluid. A coating of a process compatible material may cover the conductor 310 to provide a cylindrical shell 320. In some implementations, the coating 320 is an oxide of a material forming the conductor (such as alumina on an aluminum conductor). In some implementations, the hollow conductor 310 has an outer diameter of 2 mm, with a wall thickness of 0.5 mm.

FIG. 4A is a schematic view of a portion of an electrode assembly in a chamber. The intra-cavity electrode assembly 400 includes a plurality of coplanar wires 300 attached at a support 402. The electrode array is formed of a plurality of coplanar wires 300. The electrode assembly 400 may provide the electrode assembly 120. In some implementations, the wires 300 extend parallel to each other, at least over an area corresponding to the workpiece that has been processed.

The wires 300 are separated from each other by a wire pitch 410. The pitch 410 may affect plasma uniformity. If the spacing is too large, the filaments can cause shadowing and unevenness. On the other hand, if the pitch is too small, the plasma cannot move between the top gap 130 and the bottom gap 132, and the non-uniformity will increase or the radical density will decrease.

Generally, the value required for the wire pitch 410 depends on several factors. Examples of these factors include chamber pressure, RF power, distance between wire 300 and workpiece 115, and processing gas composition. For example, when operating at lower pressures (eg, less than 2 Torr) and with a large distance (eg, greater than 3 mm) between the wire and the workpiece, the wire spacing 410 may be increased.

In some implementations, the wire pitch 410 is uniform across the assembly 400. The wire pitch 410 may range from 3 mm to 20 mm, such as 8 mm.

4B-C are schematic cross-sectional views of electrode assemblies in a chamber having different states of a plasma region. Referring to FIG. 4B, under some operating conditions, the plasma region 412 surrounds the wire 300. Examples of such operating conditions may include driving all filaments with the same RF signal (ie, "monopolar"), and having a grounded top electrode. The plasma region 412 has an upper plasma region 414 and a lower plasma region 416. The upper plasma region 414 may be located at the top gap 130 and the lower plasma region 416 may be located at the bottom gap 132. As shown in FIG. 4B, the upper plasma region 414 and the lower plasma region 416 are connected through a gap between the wires 300 to form a continuous plasma region 412. This continuity of the plasma region 412 is to be expected because the regions 414 and 416 are "connected" to each other through the exchange of the plasma. The exchange of the plasma helps to maintain the electrical balance of the two regions, which contributes to the stability and repeatability of the plasma.

Referring to FIG. 4C, in this state, the upper plasma region 414 and the lower plasma region 416 are not connected to each other. For plasma stability, this "narrowing" of the plasma region 412 is not desired. The shape of the plasma region 412 can be changed by various factors to remove the discontinuity in the plasma region or improve the uniformity of the plasma.

In general, regions 412, 414, and 416 may have a wide range of plasma densities and are not necessarily uniform. In addition, the discontinuity between the upper plasma region 414 and the lower plasma region 416 shown in FIG. 4C represents a substantially lower plasma density relative to these two regions, and may not necessarily be completely free of electricity in the gap. Pulp.

Under some operating conditions, such as when the top electrode is absent or floating, and the workpiece support electrode is grounded, the plasma region 414 may not be formed or have a low plasma density.

In some implementations, the intra-cavity electrode assembly 400 may include a first set and a second set of wires 300. The first and second groups may be spatially arranged such that the filaments alternate between the first and second groups. For example, the first group may include wires 302 and the second group may include wires 300 and 304. The first group may be driven by a first terminal 422a of the RF power source 422, and the second group may be driven by a second terminal 422b of the RF power source 422. The RF power source 422 may be configured to provide a first RF signal at the terminal 422a and a second RF signal at the terminal 422b. The first and second RF signals may have the same frequency and a stable phase relationship with each other. For example, the phase difference between the first and second RF signals may be 0 degrees or 180 degrees. In some implementations, the phase relationship between the first and second RF signals provided by the RF power supply 422 may be adjustable between 0 and 360. In some implementations, the RF supply 422 may include two separate RF power supplies that are phase locked to each other.

Under some operating conditions, for example, when the phase difference between the first and second RF signals is 180, the resulting plasma region can be concentrated between the filaments.

The top gap 130 is a factor that affects the shape of the plasma region. When the top electrode 108 is grounded, reducing the top gap 130 generally results in a reduction in plasma density in the upper plasma region 414. The specific value of the top gap 130 may be determined based on a computer simulation of the plasma chamber. For example, the top gap 130 may be 3 mm to 8 mm, such as 4.5 mm.

The bottom gap 132 is a factor that affects the shape of the plasma region. When the workpiece support electrode 116 is grounded, reducing the bottom gap 132 generally reduces the plasma density in the lower plasma region 416. The specific value of the bottom gap 132 may be determined based on a computer simulation of the plasma chamber. For example, the bottom gap 132 may be 3 mm to 9 mm, such as 4.5 mm.

In general, chamber pressure is a factor that affects the shape of the plasma area.

5A and 5B are schematic diagrams of various examples of the configuration of the electrode assembly in the chamber. 5A and 5B, in some implementations, the electrode assembly 106 may include a first set of conductors 120a and a second set of conductors 120b. At least within the plasma chamber 104, the first and second sets of conductors 120a, 120b may be arranged in an alternating pattern. The first group may be driven by a first terminal 122a of the RF power source 122, and the second group may be driven by a second terminal 122b of the RF power source 122. The RF power source 122 may be configured to provide a first RF signal at the terminal 122a and a second RF signal at the terminal 122b. The first and second RF signals may have the same frequency and a stable phase relationship with each other. For example, the phase difference between the first and second RF signals may be 180 degrees. By driving the conductors 120a, 120b with an RF signal having a 180-degree phase difference, the resulting plasma distribution can have a lower sensitivity to imperfect RF grounding of the electrode 116. Without being bound by any particular theory, this may be because of the differential nature of the drive signal, RF current returns through adjacent electrodes. In some implementations, the phase relationship between the first and second RF signals provided by the RF power supply 122 may be adjustable between 0 and 360.

To generate a signal, an unbalanced output signal from an RF power supply oscillator can be coupled to a balun (balance-unbalance transformer) 124, which is at The terminals 122a and 122b output balanced signals. Alternatively, the RF supply 122 may include two separate RF power supplies that are phase locked to each other.

5A, the electrode assembly 120 includes a first electrode sub-assembly 510 and a second electrode sub-assembly 520. The first electrode sub-assembly 510 includes a first group of conductors 120a, and the second electrode sub-assembly 520 includes a second group of conductors 120b. The conductor 120a of the first electrode sub-assembly 510 and the conductor 120b of the second electrode sub-assembly 520 are interdigited.

The subassemblies 510, 520 each have a plurality of parallel conductors 120a, 120b that extend across the cavity 104. Each other electrode 120 (such as electrode 120a) is connected to a first bus 530 on one side of the chamber 104. The remaining (alternating) electrodes 120 (ie, electrodes 120b) are each connected to a second bus 540 on the other side of the chamber 104. The ends of the various conductors 120 that are not connected to the RF power supply bus may remain unconnected, such as floating.

The first bus 530 may be connected to the first terminal 122a, and the second bus may be connected to the second terminal 122b. The first electrode subassembly 510 and the second electrode subassembly 520 are oriented parallel to each other such that the conductors of the subassemblies 510 and 520 are parallel to each other.

In some implementations, the buses 530, 540 connecting the conductors 120 a, 120 b are located outside the internal space 104. This is better for improving the uniformity within the chamber 104. However, in some implementations, the buses 530, 540 connecting the conductors 120a, 120b are located in the internal space 104.

FIG. 5B illustrates an electrode assembly 106 similar to the implementation shown in FIG. 5A, but the ends of the various conductors 120 that are not connected to the RF power supply bus may be grounded, such as connected to a grounded bus. For example, the electrode 120a may be connected to the chamber 104 as a third bus 550 on the side of the second bus 550, and the electrode 120b may be connected to the fourth bus 560 on the same side of the chamber 104 as the first bus 530. Each bus 550, 560 can be grounded through an adjustable impedance 580 (such as an impedance matching network).

For FIG. 5A or FIG. 5B, a low-frequency common-mode bias may be optionally applied between the electrode subassemblies 510, 520. This can controllably increase the plasma potential.

FIG. 5C shows the electrode assembly 106 in the chamber, which includes a first electrode sub-assembly 522 and a second electrode sub-assembly 532. The first electrode sub-assembly 522 and the second electrode sub-assembly 532 are configured such that the wires of the sub-assemblies 522 and 532 are Extend at a non-zero angle to each other (such as perpendicular to each other).

The intra-cavity electrode assembly 106 can be driven with RF signals in various ways. In some implementations, subassembly 522 and subassembly 532 are driven with the same RF signal relative to RF ground. In some implementations, the sub-assemblies 522 and 532 are driven with differential RF signals. In some implementations, the sub-assembly 522 is driven with an RF signal, and the sub-assembly 532 is connected to RF ground.

FIG. 5D illustrates the electrode assembly 106 in the chamber, which includes a first electrode sub-assembly 524 and a second electrode sub-assembly 534, and the first electrode sub-assembly 524 overlaps with the second electrode sub-assembly 534. The first electrode sub-assembly 524 and the second electrode sub-assembly 534 each have a plurality of parallel wires 300, and the plurality of parallel wires 300 are connected at respective ends of the corresponding buses via buses 530, 540, 550, and 560. The first electrode subassembly 524 and the second electrode subassembly 534 are configured such that the filaments of the subassemblies 524 and 534 are parallel to each other, and the filaments of the subassemblies 524, 534 are arranged in an alternating pattern.

The intra-cavity electrode assembly 106 can be driven with RF signals in various ways. In some implementations, subassembly 524 and subassembly 534 are driven with the same RF signal relative to RF ground. In some implementations, the sub-assemblies 524 and 534 are driven with differential RF signals. In some implementations, the sub-assembly 524 is driven with an RF signal, and the sub-assembly 534 is connected to RF ground.

In some implementations, the center-feed 590 is used to drive the electrode assembly 106 in the chamber with RF signals in a single-ended manner. The center feed 590 is connected to the X-shaped current splitter 592 at the center. The four corners of the subassemblies 524 and 534 are connected to the X-shaped current splitter 592 using a vertical feeding structure.

In general, when sufficient RF ground cannot be provided (such as RF ground through a rotating mercury coupler, brush or slip ring), the difference between the sub-components 510, 522, 524 and the corresponding sub-components 520, 532, 534 Driving can improve plasma uniformity or process repeatability.

FIG. 6A is a schematic top view of an interior region of an example of a processing tool 650. FIG. In the processing tool 650, the workpiece support 114 is rotated about the shaft 150, and the rotation of the workpiece support 114 causes the workpiece 115 to move below the electrode assembly 600 and pass through the plasma region generated by the electrode assembly 600. Unless otherwise specified, the processing tool 650 is similar to the processing tool 200 and the electrode assembly 600 is similar to the electrode assembly 400.

As the workpiece 115 rotates around the axis 150 through the plasma region, the speeds experienced by different surface areas of the workpiece change as a function of their radial distance from the axis 150. For example, the area of the workpiece farther from the shaft 150 moves faster than the area closer to the shaft 150. For rectangular or linear plasma regions, the area of the workpiece further away from the shaft 150 experiences a correspondingly shorter dwell time in the plasma region. This radial non-uniformity of the dwell time results in non-uniformity in the amount of plasma received on the workpiece, causing unnecessary process non-uniformity.

One way to compensate for the aforementioned dwell time non-uniformity is to change the local density of the plasma region in proportion to the local speed of the wafer. For example, the local plasma density may be increased in proportion to the radial distance from the axis 150. By increasing the plasma density at regions with higher local velocities, these regions receive equal amounts of plasma in their respective shorter residence times. However, the spatial non-uniformity of the plasma density may cause uneven charging of the workpiece surface, thereby generating a potential difference on the workpiece surface. Depending on the grain size and component sensitivity, a sufficiently large potential difference on the surface (such as greater than 2 volts, 5 volts, 10 volts, 15 volts, 25 volts) may cause damage to components manufactured on the workpiece, such as thin transistor gate Dielectric breakdown of the dielectric layer.

Another way to compensate for the non-uniformity of the dwell time is by changing the geometry of the plasma area. The geometry of the plasma area can be changed such that a higher local velocity area travels through a corresponding longer portion of the plasma area to equalize the dwell time of different areas of the workpiece surface. For the configuration shown in FIG. 6A, the residence time can be balanced with a wedge-shaped plasma region. In such a configuration, the radial increase in local velocity by moving away from the shaft 150 can be offset by a proportional increase in the arc length of the wedge-shaped plasma region on each region.

The aforementioned wedge-shaped plasma region may be formed by configuring the coplanar wires and the openings 627 of the electrode assembly 600 in various ways. One way is to arrange an electrode array formed by the wires of the electrode assembly 600 in a wedge-shaped manner. For example, the respective lengths of the individual coplanar wires of the electrode array can be changed so that the overall profile of the electrode array defines a wedge shape. In some implementations, the supports 206 may provide support at respective ends of the coplanar wires of the electrode array.

Another way to form the wedge-shaped plasma region is to form a plasma region that is larger than the opening 627 by forming the opening 627 to have a wedge shape and using an electrode array of an electrode assembly 600 that is larger than the opening 627 (such as the electrode assembly 400). Then, a part of the generated plasma region may be blocked by the wedge-shaped opening to generate a wedge-shaped plasma region. For example, the support 206 may provide a wedge-shaped opening 627.

In general, various factors may affect the size of the wedge plasma area. In some applications, partial or incomplete plasma coverage on the workpiece surface can lead to adverse results. For example, the workpiece 115 may contain components sensitive to charge damage, such as a transistor with a thin gate dielectric layer. In this case, the potential generated between the area of the workpiece 115 exposed to the plasma and the area not exposed to the plasma may cause the dielectric breakdown of the gate dielectric layer, causing permanent damage to the sensitive element . By adjusting the size of the plasma area to be larger than the workpiece, this problem can be alleviated, thereby achieving complete plasma coverage on the entire workpiece surface. In some implementations, the size of the plasma area is adjusted so that the workpiece can move through the plasma area while maintaining complete plasma coverage.

In some implementations, such as when the plasma area is larger than the workpiece, the timing of applying RF power to the electrode assembly 600 can be coordinated with the movement of the workpiece 115 to ensure that the entire surface experienced by the workpiece is uniformly exposed to the plasma. For example, the plasma may be generated (ignited) after the entire workpiece is moved under the opening 627 or the electrode assembly 600, and the plasma may be turned off (extinguished) before the workpiece leaves the plasma area. In this case, the plasma area need not be wedge-shaped.

However, in some cases, using the electrode assembly 600 to generate a large plasma area (eg, greater than 300 mm × 300 mm) may be challenging. If the workpiece to be processed can withstand incomplete plasma coverage on its surface, the size of the plasma area can be adjusted to be smaller than the surface of the workpiece in one direction of the workpiece. For example, as shown in FIG. 6A, the wedge-shaped electrode assembly 600 (and thus the plasma area) is smaller than the diameter of the workpiece in the traveling direction of the workpiece 115, but is larger than the diameter of the workpiece in the radial direction with respect to the shaft 150 to achieve a diameter Full coverage in the direction.

Other considerations for adjusting the size of the plasma area include the workpiece moving speed, the target processing rate, and the target plasma exposure time to achieve the desired processing duration or throughput.

In some implementations, the plasma can be coordinated with the movement of the workpiece to ensure that a stable plasma is established before the workpiece enters the plasma area. For example, in a process that requires a relatively short plasma exposure time, the time it takes to strike the plasma may be a significant portion of the entire plasma exposure time. Because the plasma is relatively unstable during the impact phase, the resulting process repeatability may be impaired. By establishing a stable plasma before the workpiece is introduced, the plasma exposure time and dosage can be precisely controlled by controlling the speed of the workpiece as the workpiece moves through the plasma area. For such an implementation, whether the plasma area is larger or smaller than the workpiece, it is advantageous that the plasma area is wedge-shaped to compensate for the difference in exposure time. In some implementations, the generated plasma is maintained on the processing of multiple workpieces.

Assuming the processing tool 650 has a fixed plasma area size, various process parameters can be controlled to achieve the required plasma processing characteristics. Examples of process parameters that can be controlled include processing rate, exposure time, workpiece moving speed profile, number of plasma exposure passes, and total plasma exposure. For example, the workpiece may pass through the plasma area multiple times, or it may oscillate at a location within the plasma area.

6B is a schematic top view of an example of a wedge-shaped electrode assembly for generating a wedge-shaped plasma region. The wedge-shaped electrode assembly 600 has a plurality of coplanar wires 610 and a frame 620. Unless otherwise specified, the electrode assembly 600 is similar to the electrode assemblies 120, 220, and 400. The frame 620 has a first end 602, a second end 604, a center angle θca, an inner radius R ₁ , an outer radius R ₂ and a bisector 605. The first end 602 is the short end of the electrode assembly 600 and is sometimes referred to as a vertex. The second end 604 is the longer end of the electrode assembly 600 and is sometimes referred to as the base. Unless otherwise stated, the plurality of coplanar wires 610 are similar to the wires 300. Each coplanar wire 610 has a respective length L and a respective angle θ (theta) with respect to the bisector 605. The length L is defined as the linear portion of the coplanar wire 610 in a region that is parallel and adjacent to the workpiece support surface (eg, 114a). Each pair of adjacent coplanar wires 610 is separated by a corresponding interval S, and the interval S is defined as the center-to-center distance between adjacent wires. For non-parallel wires, the interval S is defined as the smallest center-to-center distance along the length of the pair of adjacent wires.

There are various considerations for determining the angle theta of the wire 610. One consideration in determining the angle theta is the trajectory of the workpiece 115 when the workpiece 115 moves under the electrode assembly 600. In some cases, the plasma generated by the electrode assembly 600 may have non-uniformities in the plasma extending along the direction of the wire 610. For example, under certain operating conditions, there may be elongated regions of reduced plasma density between a pair of filaments 610. If a point on the surface of a workpiece travels along a region of reduced plasma density, that point will receive a reduced amount of plasma exposure, resulting in uneven manufacturing. By arranging the filaments with an appropriate theta value (eg, less than or greater than 90 °, but excluding 90 °), this tangential travel along areas of reduced plasma density can be reduced, thereby improving process uniformity. For example, by setting theta to 60 °, the points on the surface of the workpiece pass under multiple filaments and are exposed to local plasma regions with reduced density and nominal density along the way, so that the time of plasma exposure is averaged. In some implementations, the respective theta of the plurality of coplanar filaments 610 are equal, that is, the filaments are parallel.

In some implementations, the respective θs of the wires 610 differ based on their respective positions within the electrode assembly 600. For example, for the wires near the apex 602 to the wires near the base 604 of the module 600, the respective theta monotonically increases to maintain the same length of the wire 610 across the electrode assembly 600. When the assembly 600 operates as an ICP source, filaments of equal length can improve uniformity.

Generally, the number of coplanar filaments 610 is determined by the size, theta, and interval S of the plasma region to achieve the desired plasma region characteristics, such as plasma density and uniformity.

In general, the interval S can be determined based on the considerations regarding the wire pitch 410 discussed in FIG. 4.

The frame 620 defines a shape of the electrode assembly 600 and a shape of a plasma region formed by the electrode assembly 600. The inner radius, outer radius, and center angle determine the size of the wedge electrode, which in turn defines the size of the plasma area. The size of the frame can be determined based on the previous discussion of adjusting the size of the plasma region in FIG. 6B.

The frame 620 may be formed of different process compatible materials. Suitable process compatible materials include those described with respect to the cylindrical shell 320, such as quartz. Other examples of process compatible materials include ceramics (such as alumina, aluminum nitride) and various silicon nitrides (such as SiN, Si ₃ N ₄ ).

Although the frame 620 has been described with respect to the wedge-shaped electrode assembly 600, the wire 610 can be formed and arranged to have the described wedge-shaped shape without the frame 620 to achieve a similar result.

Examples of wedge-shaped electrode assemblies have the following design characteristics: R ₁ = 91 mm, R ₂ = 427 mm, center angle = 31 °, theta = 60 °, wire center-to-center spacing = 15 mm, wire number = 20, frame material = quartz.

Referring to FIG. 6C, in some implementations, the frame 620 has a cutout 622. The cutout 622 may be shaped to fit the wedge-shaped top electrode 624. The wedge-shaped top electrode 624 may be grounded or biased to a bias voltage. The wedge-shaped top electrode 624 can be formed from a variety of process compatible materials, such as silicon. In some implementations, the wedge-shaped electrode is shaped to be inserted into the cutout 622 to fill the cutout 622.

Referring to FIG. 6D, a cross-sectional view of a portion of the frame 620 along a section line A is shown. In some implementations, the frame has an upper portion 625, an inner sidewall 626, and an opening 627.

Generally, the respective lengths L of the plurality of coplanar wires 610 are set to produce a plasma region of a desired shape. The frame 620 may be shaped to provide support for the coplanar wire 610. In some implementations, the end of the coplanar wire 610 is supported by the inner side wall 626 of the frame 620, similar to the configuration shown in FIG. 6B. In some implementations, the ends of the coplanar wire 610 are bent (eg, 90 °) and supported by the upper portion 625 of the frame 620, as shown in the electrode assembly 220a of FIG. 2B. In some implementations, the opening 627 of the frame 620 may determine the shape of the plasma region.

In some implementations, theta is close to 0, such as <20 °. Referring to FIG. 6E, the assembly 601 has two wires, and the wires are arranged at θ = 0 °, that is, the wires are parallel to the bisector line 605. The frame 620 of the assembly 601 has a cutout 622 and a wedge-shaped electrode 624. The wedge electrode 624 may be grounded. In such a configuration, the shape of the plasma region generated by the electrode assembly 601 is affected by the interaction between the wire 610 and the wedge-shaped electrode 624, thereby generating a wedge-shaped plasma region. In a configuration where theta is close to 0 °, as the traveling direction of the workpiece 115 with respect to the orientation of the wire 610 is substantially close to 90 °, the influence of plasma non-uniformity parallel to the wire 610 can be reduced.

7A-7D are conceptual schematic diagrams of various electrical configurations of the wedge-shaped electrode assembly. The wires of the electrode assembly can be electrically connected in various configurations. Referring to FIG. 7A, the electrode assembly 700 is similar to the electrode assembly 600 and has a first bus 730 and a second bus 740. The first bus 730 and the second bus 740 may be located on opposite sides of the chamber body 102, such as outside the chamber.

The first bus 730 has a first terminal 750 and a second terminal 751 opposite to the first terminal 750. The first bus 730 and the second bus 740 are electrically connected to respective opposite ends of the respective wires 710 of the electrode assembly 700. Unless otherwise specified, the silk 710 is similar to the silk 300. The electrode assembly 700 may be driven in various ways using one or more RF power sources.

In some implementations, the first RF power source drives the first bus 730 and the second bus 740 is connected to the RF ground. In such a configuration, RF current flows through the wire 710, and the electrode assembly can be used primarily as an ICP plasma source.

In some implementations, the first RF power source drives the first bus 730 and the second bus 740 is electrically floating. In such a configuration, the electrode assembly can be mainly used as a CCP plasma source. The RF current return path may be provided by the chamber body 102, the upper electrode 108, the wedge-shaped top electrode 624, or the workpiece support electrode 116.

In some implementations, the first RF power source drives the first bus 730 at the first end 750, the second RF power source drives the first bus 730 at the second end 751, and the second bus 740 is connected to the RF ground. In such a configuration, the electrode assembly can be mainly used as an ICP plasma source.

In some implementations, the first RF power source drives the first bus 730 and the second RF power source drives the second bus 740.

Generally, the RF driving point where the RF power is connected to the bus is selected to optimize the uniformity of the resulting plasma. For example, the driving point position may be selected based on minimizing the non-uniformity of the amplitude of the RF signal experienced by the individual wires 710.

In some implementations, the intra-cavity electrode assembly can include a first set and a second set of coplanar wires. The first and second sets of filaments may be arranged in an alternating pattern along a direction perpendicular to their longitudinal axis. In this way, the coplanar filaments alternate between the first and second groups.

Referring to FIG. 7B, an electrode assembly 702 similar to the electrode assembly 600 has a first group and a second group, the first group may include coplanar wires 710 and 714, and the second group includes coplanar wires 712. The first group is electrically connected to the first bus 732 and the second group is electrically connected to the second bus 742. One end of each wire remote from the bus to which it is connected may be "floating" or grounded. If the ends of the wires are floating, the two groups of wires can be considered to form an interdigitated array.

The first bus 732 may have a first end 752 and a second end 753 opposite the first end 752. In some implementations, the first RF power source drives the first bus 732 with a first RF signal, and the second RF power source drives the second bus 742 with a second RF signal. The first and second RF signals may have the same frequency and a stable phase relationship with each other. For example, the phase difference between the first RF signal and the second RF signal may be 0 degrees or 180 degrees. In some implementations, the phase relationship between the first and second RF signals provided by the RF power supply 422 may be adjustable between 0 and 360. In some implementations, the RF supply 422 may include two individual RF power supplies 422a and 422b that are phase locked to each other.

In some implementations, the first RF power source drives the first bus 732 and the second bus 742 is connected to the RF ground. In this case, the second bus 742 and the even wires connected to the second bus 742 may be used as an RF current return path.

In some implementations, the first RF power source drives the first bus 732 at the first end 752, the second RF power source drives the first bus 732 at the second end 753, and the second bus 742 is connected to the RF ground.

In some implementations, the first RF power source drives the first bus 732 and the second RF power source drives the second bus 742. In this case, the electrode assembly 702 can be mainly used as a CCP plasma source. The RF current return path may be provided by the chamber body 102, the top electrode 108, the wedge-shaped top electrode 624, or the workpiece support electrode 116.

Referring to FIG. 7C, an electrode assembly 704 similar to the electrode assembly 600 has a single bus 734. The bus 734 is electrically connected to both ends of the wire 710.

In some implementations, the first RF power source drives the first bus 734. The first bus 734 may have a first end 754 and a second end 755, and in some implementations, a first RF power source drives the first bus 734 at the first end 754, and a second RF power source drives at the second end 755 First bus 734. In such a configuration, the electrode assembly can be mainly used as a CCP plasma source. The RF current return path may be provided by the chamber body 102, the top electrode 108, the wedge-shaped top electrode 624, or the workpiece support electrode 116.

Referring to FIG. 7D, an electrode assembly 706 similar to the electrode assembly 600 has a first bus 736 and a second bus 746. The first bus 736 and the second bus 746 are electrically connected to respective opposite ends of the wire 710 of the electrode assembly 706. The first RF power source drives the first bus 736 at a driving point 756. The second bus 746 may be connected to the RF ground.

The first RF signal generated by the first RF power source can be attenuated by various RF loss sources. For example, the RF transmission line forming the bus 736 is lossy due to the limited conductivity of the conductor or the dielectric loss tangent due to the dielectric material forming the transmission line. As another example, the plasma load of an RF transmission line affects RF losses. Therefore, the wires 710 connected at different positions along the propagation direction of the RF signal may experience different RF signal amplitudes. For example, referring to FIG. 7A, the RF signal transmitted at the first end 750 will attenuate as it travels down the length of the first bus 730. As a result, the RF signal amplitude at the wire 710 near the second end 751 will be smaller than the RF signal amplitude at the wire 710 near the first end 750 where the RF signal is being transmitted.

A standing wave generated by the reflection of the RF signal due to imperfect RF impedance matching / termination may also cause non-uniformity in the amplitude of the RF signal along the length of the first bus 730. For example, an RF signal transmitted at the first end 750 upon reaching the second end 751 may be reflected back to the first end 750 due to the lack of an impedance matching terminal, thereby generating a standing wave along the length of the first bus 730.

This non-uniformity in the amplitude of the RF signal across the length of the first bus 730 may cause plasma non-uniformity.

By using a recursive RF feed structure, the non-uniformity of the amplitude of the RF signal across the first bus 730 can be reduced. Referring back to FIG. 7D, the first bus 736 is configured to form a recursive RF feed structure to pass the first RF signal generated by the first RF power source to the wires 710, so that for all the wires 710, from the driving point 756 to the respective wires The signal path length of 710 and the losses experienced by the RF signal are approximately equal. This approximately equal path length can enable approximately equal RF signal amplitudes at the driven end (ie, the end connected to the first bus 736) of the wire 710. In some implementations, the non-uniformity of the amplitude of the RF signal is further alleviated by configuring a recursive RF feed structure such that each branch of the structure is connected to a wire of approximately equal total length. For example, from left to right, 7, 6, 5, and 4 wires are connected to individual branches of the recursive RF feed structure, respectively. When the electrode assembly 706 operates as an ICP source, this approximately equal overall length of each branch can help improve uniformity. In some implementations, each level of the feeding structure is recursively shielded by the corresponding ground plane, and the corresponding level of the vertical through-hole connection structure penetrating the ground plane.

In the case where the electrode assembly is driven by two RF signal sources, various factors affect the shape of the plasma region generated. Examples of factors include the frequency and phase relationship of two RF signals. Referring to FIG. 7B, for example, when the frequencies of the first and second RF signals driving the first bus 732 and the second bus 742 are the same and the phase difference is set to 0 degrees ("unipolar" or "single-ended"), the electrical The pulp region is pushed out of the gap between the coplanar wires 710, resulting in discontinuities or unevenness, for example, in some cases where the spacing between the cylindrical shells is small. When the phase difference of the RF signals driving the adjacent coplanar filaments 710 is set to 180 degrees ("differential"), the plasma region is more strongly confined between the coplanar filaments 710. Any phase difference between 0 and 360 degrees can be used to affect the shape of the plasma area.

Generally, the grounding of the workpiece support electrode 116 is a factor that affects the shape of the plasma region. The imperfect RF ground of electrode 116 combined with a 0 degree phase difference between the RF signals driving adjacent coplanar wires pushes the plasma area toward the top gap. However, if an adjacent coplanar wire (such as a coplanar wire) is driven with an RF signal having a 180 degree phase difference, the resulting plasma distribution is much less sensitive to imperfect RF grounding of the electrode 116. Without being bound by any particular theory, this may be because the RF current is returned through adjacent electrodes due to the differential nature of the drive signal.

The electrical configuration and characteristics of the aforementioned electrode assemblies (such as 400, 500, 502, 504, 600, 601, 700, 702, and 704) can be dynamically changed using RF switches coupled to various positions of the electrode assembly in various configurations.

Referring to FIG. 8A, the electrode assembly 800 includes a wire 810, a first bus 820, and a second bus 824. As shown, the buses 820 and 824 may have a corresponding third end 821 and a corresponding fourth end 822. Unless otherwise stated, the silk 810 is similar to the silks 610 and 300. Each wire 810 has a corresponding first end 811 and a corresponding second end 812. The first bus 820 and the second bus 824 may be located inside the chamber body 102, in the chamber top plate, or outside the chamber, and may be at individual ends of the wires 810 to along the buses 820 and 824 (such as along the bus The lengths of 820 and 824) form electrical connections between various locations.

The wire 810 can be divided into a first multiplicity 816 wire and a second multi-817 wire. In some implementations, the filaments 810 of the first multiple 816 and the second multiple 817 may be arranged in an alternating pattern along a direction perpendicular to its longitudinal axis, such that the coplanar filaments alternate between the first and second groups, as the picture shows.

The first end 811 of the wire of the first multiple 816 may be coupled to the first bus 820. The first end 811 of the wire of the second multiple 817 may be coupled to the second bus 822. The coupling between the wire 810 and the bus can be achieved using a simple wire or metal strip (if the length is short relative to a small portion of the RF frequency's wavelength), or by using an RF transmission line (such as a coaxial cable).

In some implementations, the electrode assembly 800 further includes a third bus 826 and a fourth bus 828. In such an implementation, the second end 812 of the wire of the first multiple 816 may be coupled to the third bus 824. The second end 812 of the wire of the second multiple 817 may be coupled to the fourth bus 826.

The buses 820, 824, 826, and 828 are configured to be electrically coupled to individual wires 810 coupled thereto. The RF transmission line that forms the bus may have a length that is comparable to or greater than a significant portion of the wavelength of the RF frequency (eg,> 1/10 wavelength) and has losses due to the plasma load of the intentional silk array, ie, absorption of RF power. Therefore, the wires 810 connected at different positions along the propagation direction of the RF signal may experience different RF signal amplitudes. For example, the RF signal transmitted at the third end 821 of the first bus 820 will attenuate as it propagates down the length of the first bus 820. As a result, the RF signal amplitude at the wire 810 near the second end 822 will be smaller than the RF signal amplitude at the wire 810 near the first end 821 where the RF signal is being transmitted. This non-uniformity in the amplitude of the RF signal across the length of the first bus 820 or 824 may cause plasma non-uniformity.

Generally speaking, the plasma region generated by the electrode assembly 800 over a relatively large area may contain substantial non-uniformities in the plasma density. For example, for a plasma area of 40 cm long x 40 cm wide, a significant difference in plasma uniformity can be observed between RF signal frequencies of 13.56 MHz and 60 MHz. When driven at a lower frequency (eg, 13.56 MHz), the plasma density can decrease away from the ends 811 and 812 toward the center of the wire 810. However, along the direction perpendicular to the longitudinal axis of the wire, the time average of the plasma density remains substantially spatially uniform. When driven at higher frequencies (such as 60 MHz), the plasma density becomes more uneven along both the filament and the longitudinal axis perpendicular to the filament. For example, a periodic distribution of local maximums and minimums can be formed in two directions. Without wishing to be bound by theory, this pattern of non-uniformity may be caused, at least in part, by the presence of standing waves.

By using an RF switch to dynamically change the electrical characteristics of the electrode assembly 800, it may be possible to reduce this non-uniformity. It may also be possible to intentionally introduce non-uniformities in the voltage signal to compensate for other sources of non-uniformity in the workpiece, such as non-uniform layer thicknesses, or plasma density (such as non-uniform gas distribution).

Referring to FIG. 8B, the switching electrode system 802 includes a first RF switch 830, a second RF switch 834, a third RF switch 836, a fourth RF switch 838, a first tap 840, and a second tap 842. Generally, the first and second taps 840 and 842 can be connected to various signals and potentials to generate a plasma, for example, to the first and second RF signals, RF ground.

Each RF switch includes a first terminal 831 and a second terminal 832. In general, the RF switch 830 operates bidirectionally, and the first and second ends 831 and 832 do not depend on a specific physical terminal of the RF switch, but are used to represent two different terminals of the RF switch. Various RF switching components can be used to provide RF switches 830, 834, 836, and 838. Examples of RF switching components include mechanical relays or switches, PIN diodes, saturable inductors / reactors, MOSFETs, electronic circuits including these components, and when combined with RF power generators with adjustable RF signal frequencies Frequency-dependent impedance circuit.

Generally, the first and second taps 840 and 842 can be positioned along individual lengths of the buses 820, 824, 826, and 828, for example, in the middle of the bus. In some implementations, the first tap 840 is located in the middle of the first bus 820, and the second tap 842 is located in the middle of the fourth bus 828.

In some implementations, the first and second taps 840 and 842 are differentially driven by two RF signals having the same frequency (eg, 60 MHz) and a relative phase difference of 180 degrees.

In general, the first and second terminals 831 and 832 of the RF switch may be coupled to the bus in various ways to achieve various effects. For example, individual first terminals of RF switches 830, 834, 836, and 838 are connected to the ends of buses 820, 824, 826, and 828, as shown. In such a configuration, the closing of any of the RF switches 830, 834, 836, and 838 causes the corresponding end ("corner") of the bus to be electrically connected or "short-circuited". The short circuit at the corner may cause a change in the RF reflection coefficient at the position, so that the amplitude and power coupling of the RF signal at a local area of the wire 810 near the shorted corner is reduced, thereby reducing the generation of local plasma. Shorts in the corners may also move and / or change the spatial distribution of the maximum and minimum values in the plasma density.

Generally, electrical connections and couplings can be provided by wires, coaxial cables, waveguides, or through physical contact (such as forging, welding, one-piece manufacturing).

Generally, the uniformity of the process of the workpiece can be improved by averaging the exposure time of the plasma. One way to achieve time averaging of the plasma exposure is through the spatial distribution of non-uniformities in the moving plasma area. For example, by turning on and off ("modulation") RF switches coupled to the four corners of the electrode assembly, the plasma density distribution (non-uniformity) can be moved.

RF switches 830, 834, 836, and 838 can be modulated in various ways to achieve the required time-averaged plasma density. An example of a program for modulating an RF switch is to cyclically connect point pairs on different buses. For example, the system can operate as follows: (1) turn off the RF switch 830 for the first duration and then turn on, (2) turn off the RF switch 834 for the second duration and then turn on, and (3) turn off the RF switch 836 for the third duration (4) Turn the RF switch 838 off for a fourth duration. The first to fourth durations can be determined based on the required program repetition rate. For example, the repetition rate can be set to be much faster than the time scale of certain effects, such as device charging. For example, in a program with 4 states, the duration of each state including the dead time can be set to 50 μs to achieve a repetition rate of 5 kHz.

In some implementations, the dead time is inserted between steps of the program. The dead time can provide "break before make" contact to prevent shorting of two or more generators in some configurations. In some implementations, the closing of the switches may overlap in time. For example, two switches can be modulated simultaneously, such as paired diagonal switches (830-838, 834-836) and pairs of adjacent switches (830-834 and 836-838, 832-836, and 834-838) . As another example, all four switches can be turned on and off simultaneously.

Referring to FIG. 8C, an example of a switching electrode system 804 is shown. Unless otherwise specified, the switched electrode system 804 is similar to the system 802. The switching electrode system 804 includes a first RF switch group 850, a second RF switch group 854, a third RF switch group 856, and a fourth RF switch group 858. The first RF switch group 850 includes sub switches 860a and 860b, the second RF switch group 854 includes sub switches 860c and 860d, the third RF switch group 836 includes sub switches 860e and 860f, and the fourth RF switch group 838 includes sub switches 860g And 860h. The sub-switch is similar to the RF switch 830.

The first terminal 831 of the sub-switch is connected to the terminals of the buses 820, 824, 826, and 828. In some implementations, the second terminal 832 of the sub-switch is connected to the RF ground. In such a configuration, the closing of any one of the sub-switches electrically couples individual ends of the bus to RF ground or grounds the ends of the bus. Grounding the end of the bus may reduce the amplitude of the RF signal in a local area of the wire 810 near the RF ground end of the bus, and cause a reduction in the amplitude of the electric field in the area or a lower power coupling. A reduction in the magnitude of the electric field may result in a reduction in plasma generation in this area.

The RF switch group and individual sub-switches can be modulated in various ways to provide modulation of the plasma density distribution. For example, each RF switch group can be operated as a single unit, where the sub-switches of the RF switch group are turned on and off as a single unit. As another example, the sub-switches of each RF switch group can be independently turned on and off.

The switch can be tuned in a variety of different procedures in a manner similar to the various procedures described with respect to FIG. 8B. For example, you can operate a switching electrode system by turning off one switch group at a time (optionally with a time delay), turning off the switch groups cyclically during different groups of off time, alternating the switch groups, or turning them on simultaneously And turn off all switches.

As another example, the system can operate as follows: (1) turn off the first and third RF switch sets 850 and 856 for a first duration and then turn on, (2) turn on all switches, and (3) turn off the second and fourth RF Switch groups 854 and 858 are turned on for a second duration and then turned on.

As yet another example, the system can operate as follows: (1) turn off the first switch group 850 for the first duration and then turn on, (2) turn off the second switch group 854 for the second duration and then turn on, (3) turn off the third The switch group 856 is turned on for a third duration and then turned on, (4) the fourth switch group 858 is turned off for a fourth duration and then turned on, (5) all switch groups are turned on, and (6) all switch groups are turned off.

In some implementations, RF switches can be used to dynamically reconfigure the feed of RF signals to various locations on the bus. Referring to FIG. 8D, an example of a switching electrode system 806 is shown. Unless otherwise stated, the switched electrode system 806 is similar to the system 804 and can operate in a similar manner.

The first multiplex 816 is driven with RF signals at taps 844 and 846. The RF signals driving the taps 844 and 846 may be the same frequency or different frequencies. For the same frequency, the phase relationship between the two signals can be any value between 0, 180, or 0 to 360. For some implementations, the phase relationship can be adjusted over time. As shown, the second terminals 832 of the sub-switches 860a, 860c, 860f, and 860h are connected to the corresponding taps 844 and 846.

In such a configuration, the corresponding sub-switches can be used to modulate the ground characteristics of the second multiple 817, and the RF signal can be transmitted from different locations (eg, from terminals 821 and 822) to the buses 820 and 826. The combination of grounding characteristics and modulation of the RF signal distribution can be used to modulate the plasma density to improve processing uniformity by time averaging.

In such a configuration, it may be advantageous to maintain at least one of the sub-switches 860 in an off state to provide a continuous RF signal supply to the component 800.

Referring to FIG. 8E, an example of a switching electrode system 808 is shown. Unless otherwise stated, the switched electrode system 808 is similar to the system 804 and can operate in a similar manner. The second terminal 832 of the sub-switch is connected to a single tap 848. A symmetrical distribution network as shown can be used to improve the uniformity of the RF signals delivered to the four corners of the system 808. The sub-switches can be tuned in various ways previously described to change the plasma distribution and improve processing uniformity.

In some implementations, switches can be distributed across the bus to allow finer control of instantaneous plasma uniformity, thereby improving time-averaged plasma uniformity. Referring to FIG. 8F, an example of a switching electrode system 801 is shown. Unless otherwise stated, the switched electrode system 801 is similar to the system 808 and can operate in a similar manner. The first bus 820 is coupled to a first RF switch group 870, such as three or more sub-switches. Each RF switch group includes a plurality of sub-switches 860. The first terminals of the sub-switches 860 of the first RF switch group 870 are electrically coupled to the first bus at various positions across the length of the first bus 820. In some implementations, the coupling points are approximately equally spaced, as shown. The second terminal of the sub-switch 860 of the first RF switch group 870 is electrically coupled to the tap 848 to receive an RF signal.

The second, third, and fourth buses 824, 826, and 828 are connected to the second, third, and fourth RF switch groups 874, 876, and 878, respectively, each of which is similar to the first bus 820 and the first RF switch group 870 way to connect.

In such a configuration, additional hierarchical control over the transmission position of RF signals along the length of the bus can result in improved time-averaged plasma uniformity.

Generally, the number of sub-switches included in the RF switch group can be determined based on, for example, the length of the bus, the size of the plasma area, the RF signal frequency and power, and the chamber pressure.

In some implementations, RF switches can be used to dynamically reconfigure RF signal feed and ground positions to provide a mode-selectable plasma source that can switch between the main CCP mode and the main ICP mode . Referring to FIG. 9A, an example of a switching electrode system 900 is shown. Unless otherwise stated, the switched electrode system 900 is similar to the system 802 and can operate in a similar manner. The first terminals 831 of the RF switches 830 and 834 are connected to respective third terminals 821 and 822 of the second bus 824, and the first terminals 831 of the RF switches 836 and 838 are connected to respective third terminals of the third bus 826 821 and fourth end 822, as shown. The second terminal 832 is connected to the RF ground.

The RF switches 830, 834, 836, and 838 can be controlled in various ways to change the main mode of plasma generation by the switchable electrode assembly 900. For example, by turning off all four RF switches, RF current flows along the length of the wire 810, generating a magnetic field and generating a mainly inductively coupled plasma. By turning on all four switches, the RF current is reduced, and the component 900 generates a primarily capacitively coupled plasma.

In some implementations, the first and second RF signals driving the respective taps 840 and 842 have a phase difference of 180 degrees, ie, differential driving. In this case, the alternating wires 810 belonging to the first and second multiples 816 and 817 are fed from opposite ends of the RF signal having a phase difference of about 180 degrees, resulting in the generation of an auxiliary RF magnetic field. In some implementations, the first and second RF signals driving the respective taps 840 and 842 have a phase difference of about 0 degrees. In this case, the alternating wires 810 belonging to the first and second multiples 816 and 817 are fed from opposite ends of an RF signal having a phase difference of about 0 degrees, resulting in the generation of opposite RF magnetic fields.

In some implementations, switches can be distributed across the bus to allow finer control of instantaneous plasma uniformity, thereby improving time-averaged plasma uniformity. Referring to FIG. 9B, an example of the switching electrode assembly 902 is shown. Unless otherwise stated, the switchable electrode assembly 902 is similar to the system 801. The first bus 820 is coupled to a first RF switch group 870 including a plurality of sub-switches 860.

The first terminals of the sub-switches 860 of the first RF switch group 870 are electrically coupled to the first bus at various positions across the length of the first bus 820. In some implementations, the coupling points are approximately equally spaced, as shown. The second terminal of the sub-switch 860 of the first RF switch group 870 is electrically coupled to the tap 940 to receive the first RF signal.

The second bus is connected to the second RF switch group 874 at the first terminal of the sub-switch, and the second terminal of the sub-switch is connected to the RF ground.

The third bus is connected to the third RF switch group 876 at the first terminal of the sub-switch 860, and the second terminal 832 of the sub-switch 860 of the third RF switch group 876 is connected to the RF ground.

The fourth bus is connected to the fourth RF switch group 878 at the first terminal of the sub-switch, and the second terminal of the sub-switch is electrically coupled to the tap 942 to receive the second RF signal.

The first and second RF signals driving the taps 940 and 942 may be at the same frequency or different frequencies. For the same frequency, the phase relationship between the two signals can be any value between 0, 180, or 0 to 360. For some implementations, the phase relationship can be adjusted over time.

The RF switch groups 870, 874, 876, and 878 can be controlled in various ways to change the main mode of plasma generation through the switchable electrode assembly 902. For example, by turning off at least one sub-switch from each of the first group 870 and the fourth group 878, and turning on the second and third RF switch groups 874 and 876, the component 902 generates a primarily capacitively coupled plasma.

As another example, by turning off at least one sub-switch from each of the first group 870 and the fourth group 878, and turning off all sub-switches of the second and third RF switch groups 874 and 876, the component 902 generates a main Inductively coupled plasma. In some implementations, the first and second RF signals driving the respective taps 940 and 942 have a phase difference of 180 degrees, ie, differential driving. In this case, the alternating wires 810 belonging to the first and second multiples 816 and 817 are fed from opposite ends of the RF signal having a phase difference of about 180 degrees, resulting in the generation of an auxiliary RF magnetic field. In some implementations, the first and second RF signals driving the respective taps 940 and 942 have a phase difference of about 0 degrees. In this case, the alternating wires 810 belonging to the first and second multiples 816 and 817 are fed from opposite ends of an RF signal having a phase difference of about 0 degrees, resulting in the generation of opposite RF magnetic fields.

In some processing applications, an ICP that uses an opposite RF magnetic field that can deposit RF power in the plasma in a manner approximately parallel to a silk band can provide a more uniform plasma, especially when the workpiece is near a plasma source (such as Electrode assembly), that is, the small bottom gap 132. Therefore, it may be beneficial to have the ability to change the phase relationship of the first and second RF signals.

In general, individual sub-switches of the first and fourth groups 870 and 878 can be adjusted to change the plasma density distribution. In addition, in the case where the switching electrode assembly 902 is configured to generate a main inductively coupled plasma, the sub-switches of the second and third groups 874 and 876 can be individually adjusted to further change the plasma density distribution.

Generally speaking, although the digital display bus is driven near the center and the terminal is floating or has a ground terminal, it is in other locations (such as driven end, termination) It may be advantageous to be driven or terminated.

In general, where the second terminal of the RF switch is connected to the RF ground, a variable impedance can be placed in series with the RF ground to provide a variable RF terminal impedance to further control the change in plasma density.

Generally, although the illustration shows a tap connected to the center of the corresponding bus, the tap used to apply RF power to the electrode assembly may be located at one or more ends, centers, or other locations on the bus.

Switches can be used to improve the time-averaged plasma uniformity of a wedge-shaped electrode assembly. Referring to FIG. 10, an example of the switching electrode assembly 1000 is shown. The switching electrode assembly 1000 includes a wedge-shaped electrode assembly 1010. Unless otherwise specified, wedge-shaped electrode assembly 1010 is similar to wedge-shaped electrode assembly 704. The assembly 1010 includes a wedge-shaped top electrode 624, which may be grounded. The switchable electrode assembly 1000 includes a first RF switch 1030, a second RF switch 1034, a third RF switch 1036, a fourth RF switch 1038, and a tap 1040. The RF switch is similar to the RF switch 830. A first terminal of the RF switches 1030 and 1034 is connected to the first terminal 754 of the component 1010, and a first terminal of the RF switches 1036 and 1038 is connected to the second terminal 755 of the component 1010. The second terminals of the first and fourth RF switches 1030 and 1038 are connected to each other and to the tap 1040, and the second terminals of the second and third RF switches 1034 and 1036 are connected to the RF ground.

The first and fourth RF switches 1030 and 1038 may be turned on and off to selectively feed RF signals to the first end 754, the second end 755, or both ends of the component 1010. The second and third RF switches 1034 and 1036 can be turned on and off to selectively ground either the first end 754 or the second end 755 of the component 1010.

RF switches can be tuned in various ways to improve time-averaged plasma uniformity. The following is an example of the program: (1) Turn off the RF switch 1030 for the first duration, and turn on the switches 1034, 1036, and 1038 (such as up to 30 microseconds), (2) Turn off 1030, 1036, and turn on 1034, 1038 (such as 40 microseconds), and then (3) turn off 1036 and turn on 1030, 1034, and 1036 (for example, up to 30 microseconds). Alternatively, the unpowered terminal may be grounded after a short delay after the RF signal is applied to the other terminal, and the ground terminal may not be grounded before the RF signal is applied to the terminal.

The following is another example of the program: (1) 1030 = ON, 1038, 1034, 1036 = OFF for 30 microseconds, (2) 1030, 1038 = ON, 1034, 1036 = OFF for 40 microseconds, (3) 1038 = ON, 1034, 1030, 1036 = OFF for 30 microseconds, and then repeat the cycle many times until the process steps are completed or the cycle is reversed alternately. Alternatively, the non-powered end may be grounded after a short delay after power is applied to the other end, and the grounded end may not be grounded before power is applied to that end.

In general, the wedge-shaped electrode assembly 1010 may be similar to an electrode. Generally speaking, the switch can be applied to other electrode components, such as 600, 601, 700, 702, 704.

Various circuit implementations can be used to provide RF switches suitable for switching RF signals for plasma generation. There are various considerations for implementing RF switches (such as RF switch 830, sub-switch 860) to be used in a switched electrode system. Examples of these considerations include RF power processing capability, switching speed, ON-state impedance, OFF-state impedance, and bidirectionality.

Generally, when the impedance between the two terminals of the switch is low, the switch is considered to be "ON" or closed, and when the impedance is high, the switch is considered to be "OFF" ) "Or open.

PIN diode switches can be used to provide suitable RF switches. 11A, the PIN diode switch 1100 includes a PIN diode 1110, a first capacitor 1120 having a capacitance C1, a second capacitor 1122 having a capacitance C2, and an inductor 1140 having an inductance L1. The switch 1100 has a first terminal 1131, a second terminal 1132, and a control terminal 1134. The first terminal 1131 may provide a first terminal 831, and the second terminal 1132 may provide a second terminal 832 of the RF switch 830.

The first capacitor 1120 and the inductor 1150 may be connected in parallel between the first terminal 1131 and the second capacitor 1122. Then, the PIN diode 1110 may be connected in parallel with the first capacitor 1120, the inductor 1150, and the second capacitor 1122 between the first terminal 1131 and the second terminal 1132. The control terminal 1134 may be connected between the second capacitor 1122 and the first capacitor 1120.

The PIN diode 1110 is a diode having a wide undoped intrinsic semiconductor region between a p-type semiconductor and an n-type semiconductor region, and a fast switch that can be very suitable for high-power RF signals. PIN diodes have anode (+) and cathode (-), and when a forward bias is established between the anode and cathode (such as> 0.7 V and / or diode current> 100 mA), can be provided for RF Low impedance conduction path of the signal, such as <1 ohm.

The PIN diode switch 1100 operates based on the following working principle. The impedance of the PIN diode 1110 can be controlled by providing a control signal to the control terminal 1134. The control signal is a quasi static voltage switched between a first level (such as 0.7V) and a second level (such as -2kV). Due to the quasi-static nature of the control signal, the control voltage and any resulting diode current can be conducted through the inductor 1140. In addition, the second capacitor 1122 prevents the control voltage from reaching the cathode. By providing the anode with a negative control voltage (eg -2kV) that is sufficiently large relative to the cathode, the PIN diode 1110 can be set to the "OFF" state, presenting a high impedance between its cathode and anode. When a sufficiently large positive control voltage (such as 0.7V) is applied, the PIN diode 1110 can be set to the "ON" state, presenting a low impedance path (such as <1 ohm) for the RF signal between the terminals 1131 and 1132. .

The first capacitor 1120 and the inductor 1140 connected in parallel form a parallel LC resonator 1150 as shown in the figure. Resonator 1150 has Determine the resonant frequency. At the resonance frequency f ₀ , the resonator 1150 exhibits a high impedance close to an open circuit (eg,> 1000 ohms), which depends on the quality factor of the resonator. By selecting the values of C1 and L1 such that the resonance frequency is aligned with the frequency of the RF signal existing at the terminal 1131 or 1132, the RF signal can be prevented from passing through the resonator 1150.

Generally, the capacitance C2 of the second capacitor 1122 can be set to provide a low impedance path at the frequency of the RF signal.

In some implementations, the first capacitor 1120 is a variable capacitor ("capacitor") with an adjustable capacitance C1 that can be changed to optimize the resonance of the parallel LC circuit formed by the first capacitor 1120 and the inductor 1140 to interact with Frequency alignment of RF signals.

In some implementations, a control signal buffer amplifier 1136 may be provided to buffer and / or amplify the control signal applied at the control terminal 1134 to the anode of the PIN diode 1110.

Generally, multiple PIN diode switches can be used in combination to achieve a range of impedance values between the first and second terminals 1131 and 1132. The control signal can also be set between the first and second levels to provide a variable impedance.

In some implementations, the first terminal 1131 is connected to a bus (such as the bus 820), and the second terminal 1132 is connected to the RF ground to form a path to the RF ground. In some implementations, the first terminal is connected to a first bus (such as bus 820) and the second terminal 1132 is connected to a second bus (such as bus 824). In this case, the switch can be considered "floating", The potential of the second terminal 1132 is defined by an external factor.

As another example, a saturable inductor switch can be used to provide a suitable RF switch. 11B, the saturable inductor switch 1102 includes a saturable inductor 1160, a first capacitor 1124 having a capacitance C1, and a second capacitor 1126 having a capacitance C2. The switch 1102 includes a first terminal 1131, a second terminal 1132, and a control terminal 1135. The first terminal 1131 may provide a first terminal 831, and the second terminal 1132 may provide a second terminal 832.

The saturable inductor 1160 has a primary winding 1162 having an inductance L1 and a control winding 1164 having an inductance L2. In some literature, saturable inductors may also be referred to as saturable inductors or magnetic amplifiers. A saturable inductor is an inductor with a magnetic core that allows the current to flow through the control winding 1164 to intentionally saturate the magnetic core. Once saturated, the inductance L1 of the primary winding 1162 will drop significantly. The reduced inductance of the primary winding reduces the impedance of the RF signal, which can be used to implement switching.

The primary winding 1162 of the inductor 1160 may be connected in series with the second capacitor 1126, and the first capacitor 1124 may be connected in parallel with the primary winding 1162 and the second capacitor 1126 between the first terminal 1131 and the second terminal 1131. The control terminal 1135 is connected to a control winding 1164, which can then be connected to ground.

The saturable inductor switch 1102 operates based on the following operating principles. The first capacitor 1124 connected in parallel with the series combination of the primary winding 1162 and the second capacitor 1126 forms a parallel LC resonator, which operates similarly to the LC resonator 1150. For example, you can set the values of C1, C2, and L1 so that when the control signal is set to "OFF" or low state, the resonance of the switch 1102 occurs at the RF signal frequency (such as 60MHz), and there is no A current flows through the control winding 1164. In this state, the switch 1102 is in an "open circuit" state and exhibits high impedance between the first and second terminals 1131 and 1132. When the control signal applied to the control terminal 1135 is set to "ON" or high state, the magnetic field generated by the current flowing through the secondary winding 1164 saturates the core of the saturable inductor 1160, thereby reducing the primary winding 1162's Inductance L1. The reduction of the inductance L1 changes the resonance frequency of the switch 1102, and presents a low impedance between the first and second terminals 1131 and 1132 at the same RF signal frequency. This low-impedance state can be used as the closed-circuit state of the switch 1102.

In some implementations, a control signal buffer amplifier 1137 may be provided to amplify and / or buffer the control signal applied at the control terminal 1135 so that a current sufficient to saturate the saturable inductor 1160 may be applied to the control winding 1164.

In some implementations, a low-pass filter 1138 may be provided between the control signal terminal 1135 and the control winding 1164 to mitigate noise coupling from the control signal and / or RF signal propagating to the control signal terminal.

Generally, by adjusting the control signal to provide a range of current to the control winding 1164, the switching of the switch presented between the first terminal 1131 and the second terminal 1132 can be controlled between the "ON" state and the "OFF" state. impedance.

In some implementations, the first terminal 1131 is connected to a bus (such as bus 820), and the second terminal 1132 is connected to RF ground. In some implementations, the first terminal is connected to a first bus (such as bus 820) and the second terminal 1132 is connected to a second bus (such as bus 824).

The impedance presented by the aforementioned switches 1100 and 1102 and their switching states are controlled by the application of a control signal. However, in some implementations, the characteristics of the switch can remain static, but the frequency of the RF signal can be adjusted so that the switch presents an "open circuit" or "closed circuit" state to RF signals with different frequencies. For example, the frequency-dependent impedance of a circuit can be used to provide such a frequency-based switch.

Referring to FIG. 12A, the frequency-based switch 1200 includes a first capacitor 1220 having a capacitance C1, a second capacitor 1222 having a capacitance C2, a first inductor 1240 having an inductance L1, and a second inductor 1242 having an inductance L2. The switch 1200 has a first terminal 1231 and a second terminal 1232.

The first capacitor 1220 and the first inductor 1240 may be connected in series, and the second capacitor 1222 and the second inductor 1242 may be connected in series. The pair of circuits may be connected in parallel between the first terminal 1231 and the second terminal 1232.

The combination of L1, C1, L2, and C2 can be set so that at the first frequency (such as 58MHz), a low impedance (such as <0.1 ohm) appears between the first and second terminals 1231 and 1232, and at the second frequency (Such as 62MHz), high impedance (such as> 100 ohms). For example, the following values of L1 = L2 = 0.1μH, C1 = 75.3pF, and C2 = 58.6pF can provide low-impedance resonance at 58MHz and high-impedance resonance at 62MHz.

Without wishing to be bound by theory, a low-impedance resonance can be provided by a series LC resonance, and a high-impedance resonance can be provided by a parallel LC resonance.

Capacitance and inductance can be set to form a frequency-based switch that has approximately complementary responses to the examples provided above. For example, the following values L1 = L2 = 0.1μH, C1 = 65.9pF, C2 = 87.8pF can provide low-impedance resonance at 62 MHz and high-impedance resonance at 58 MHz, which are approximately complementary or opposite to the first example response. This complementary behavior can be used to form various frequency-switching electrode systems.

In some implementations, discrete capacitors and inductors can be implemented with distributed circuit elements (such as transmission line segments, stubs).

Referring to FIG. 12B, the frequency-switching electrode system 1202 includes an electrode assembly 800, a first frequency-based switch 1200a, a second frequency-based switch 1200b, and a tap 1260. RF signals of different frequencies can be provided to the tap 1260, for example, using a variable frequency RF generator with a matching network and an isolator or circulator in series.

In this configuration, the frequency of the RF signal supplied through the tap 1260 can be alternated from the first frequency to the second frequency, so that more RF signals are coupled to the left side of the electrode assembly 800 through the switch 1200a, or through the switch 1200b Coupling to the right side of the electrode assembly 800. Alternatively, the frequency of the RF signal provided through the tap 1260 may be driven, such as with a ramp function, to change between the first frequency and the second frequency.

For example, by setting the component values to L1a = L2a = 0.1 μH, C1a = 75.3pF, C2a = 58.6pF, the first switch 1200a can provide low impedance resonance at 58 MHz and high impedance resonance at 62 MHz. The component values of the second switch 1200b can be set to L1 = L2 = 0.1 μH, C1 = 65.9pF, C2 = 87.8pF to provide low-impedance resonance at 62MHz and high-impedance resonance at 58MHz. In such a configuration, by switching the frequency of the RF signal to a first frequency (eg, 58 MHz), most of the RF signals can be coupled to the left side of the electrode assembly 800 through the first switch 1200a, and by changing the frequency of the RF signal Switching to the second frequency (such as 62 MHz), most RF signals can be coupled to the right side of the component 800 through the second switch 1200b. When the frequency is in the middle between the two frequencies, approximately at about 60 MHz, the power is approximately similarly coupled at both ends, and high center non-uniformity may result.

In some implementations, a transmission line segment can be used to change the frequency-dependent impedance of the switch 1200. For example, considering the speed factor of the transmission line, a quarter-wavelength transmission line segment may be used to connect the corners of the electrode assembly 800 to the terminals of the switches 1200a and 1200b. By using a quarter-wavelength transmission line, the impedances presented at the first and second frequencies can be exchanged. For example, the low impedance of series resonance can be converted to a high impedance of about 1000 ohms, and the high impedance of parallel resonance can be converted to a low impedance of about 1 ohm.

In some implementations, the frequency-based switch 1200 can be used as a frequency-selective terminal to provide impedance matching terminals at different frequencies to control the coupling of RF signals into the electrode assembly. Referring to FIG. 12C, the frequency switching electrode system 1204 includes an electrode assembly 800, a first frequency selective terminal 1250a, a second frequency selective terminal 1250b, and a tap 1260. Unless otherwise stated, the frequency selection terminals 1250a and 1250b may be provided by a frequency-based switch 1200 and operate in a similar manner.

In some implementations, the component values of the frequency-selective terminals 1250a and 1250b may be set so that at the first frequency, the terminal 1250a presents the characteristic impedance of the RF generator and the transmission line, and the terminal 1250b presents a high impedance. In such a configuration, the terminal 1250a provides an impedance-matched terminal to the RF ground, minimizing RF signal reflection and coupling of the RF signal to the left side of the electrode assembly 800. At the same time, the high impedance presented by the terminal 1200b allows RF signals to be coupled to the right side of the electrode assembly 800.

In some implementations, the component values of the frequency selective terminals 1250a and 1250b may be set such that at the first frequency, the terminal 1250a presents a low impedance path to RF ground, and the terminal 1250b presents a high impedance. In such a configuration, the low impedance path provided by the terminal 1250a to the RF ground minimizes the RF signal coupled to the left side of the electrode assembly 800. At the same time, the high impedance presented by the terminal 1200b allows RF signals to be coupled to the right side of the electrode assembly 800.

In general, frequency-based switches and frequency-selective terminations can be coupled to various locations along the bus. For example, an additional pair of coupling points to a tap may be provided at approximately the center of the bus, and additional switches or terminations may be provided at those coupling points.

In general, frequency switching is not limited to two states corresponding to a high-impedance state and a low-impedance state, but can be advantageously operated continuously between or outside the first and second switching frequencies.

In general, various combinations of frequency-based switches with various resonance frequencies can be used to extend frequency-based switching to 3, 4 or more frequencies.

In some plasma chambers, the workpiece moves through the plasma processing area on, for example, a linear or rotating workpiece support. In such a chamber, a moving workpiece support can be DC grounded through, for example, a rotating mercury coupling, a brush, or a slip ring. However, moving workpiece supports may not be adequately grounded at RF. The RF ground path should have a much lower impedance than the plasma to make it an adequate RF ground. The lack of an adequate RF ground path may make it difficult to control the ion energy at the workpiece and reduce process repeatability.

Therefore, there is a need for a plasma source having the following characteristics: it can effectively produce a uniform plasma with the required characteristics (plasma density, electron temperature, ion energy, dissociation, etc.) on the size of the workpiece; it can uniformly adjust the operating window Properties (such as pressure, power, gas composition); it has stable and repeatable electrical properties even when the workpiece moves; and it does not produce excessive metal contaminants or particles.

Fig. 13 is a schematic side view of another example of a plasma reactor. The plasma reactor 2100 has a chamber body 2102 which surrounds an internal space serving as a plasma chamber. The chamber body 2102 may have one or more side walls 2102a, a top plate 2102b, and a bottom plate 2102c. The internal space 2104 may be cylindrical, such as for processing round semiconductor wafers. The plasma reactor includes a top electrode array assembly 2106 on top of the plasma reactor 2100. The top electrode array assembly 2106 may be adjacent to the top plate (as shown in FIG. 13), or suspended in the internal space 2104 and separated from the top plate, or form a part of the top plate. Some parts of the side wall and the bottom plate of the chamber body 2102 may be separately grounded.

The gas distributor is located near the top plate of the plasma reactor 2100. The gas distributor may include one or more ports 2110 in the side wall 2102, which are connected to a process gas supply 2112. Alternatively or in addition, the gas distributor may be integrated with the top electrode assembly 2106 into a single component. For example, a channel connected to the process gas supply 2112 may be formed by a dielectric plate in the assembly 2112 to provide an opening in the top plate of the plasma chamber. The gas supply 2112 delivers one or more process gases to a gas distributor 2110, and the composition of the process gas may depend on the process to be performed, such as deposition or etching.

A vacuum pump 2113 is connected to the internal space 2104 to evacuate the plasma reactor. For some processes, the chamber operates in the Torr range, and the gas distributor supplies argon, nitrogen, oxygen, and / or other gases.

Depending on the chamber configuration and the supplied processing gas, the plasma reactor 100 may provide ALD equipment, etching equipment, plasma processing equipment, plasma enhanced chemical vapor deposition equipment, plasma doping equipment, or plasma surface cleaning equipment.

The plasma reactor 2100 includes a workpiece support 2114 (such as a base) for supporting the workpiece, and a top surface supporting the workpiece is exposed to a plasma formed in the chamber 2104. The work support 2114 has a work support surface 2114a facing the top electrode 2108. In some implementations, the workpiece support 2114 includes a workpiece support electrode 2116 inside the support 2114, and a workpiece bias voltage supply 2118 is connected to the workpiece support electrode 2116. The voltage supply 2118 may apply a voltage to clamp the workpiece 2115 to the support 2114 and / or supply a bias voltage to control characteristics of the generated plasma, including ion energy. In some implementations, the RF bias power generator 2142 is AC coupled to the workpiece support electrode 2116 of the workpiece support 2114 through the impedance matching 2144.

In addition, the support 2114 may have an internal channel 2119 for heating or cooling the workpiece 2115, and / or an embedded resistance heater (2119).

The electrode assembly 2106 is positioned at the top plate of the chamber 2104. The electrode assembly 2106 includes a plurality of conductors 2120 that extend laterally above the workpiece support 2114. The conductor 2120 is coplanar, at least in the area above the expected position of the workpiece on the support 2114. For example, in this area, the conductor may extend parallel to the support surface 2114a. The plurality of conductors 2120 may be arranged as an array of parallel lines. In some implementations, the conductor may have a "U-shape" with both ends connected to respective buses on the same side of the cavity 2104. Alternatively, the conductor may be arranged in a staggered spiral (staggered circular spiral or staggered rectangular spiral). The longitudinal axis of the conductor 2120 may be arranged at a non-zero angle (eg, an angle greater than 20 degrees) with the moving direction of the workpiece 10 below the electrode assembly 2106. For example, the longitudinal axis of the conductor 2120 may be substantially perpendicular to the moving direction of the workpiece 10.

A gap 2132 is formed between the workpiece support 2114 and the electrode assembly 2106. For high pressure (such as 1-10 Torr), the gap 2132 may be 2-25mm. Fixing the workpiece may require a larger minimum gap, such as about 5 mm, depending on the electrode-to-electrode spacing on the source and the thickness of the dielectric cover. At lower pressures (eg, less than 100mTorr), the gap 2132 can be from 1 cm to 50 cm.

In some implementations, the fluid supply 2146 circulates fluid through the electrode assembly 2106. In some implementations, the heat exchanger 2148 is coupled to the fluid supply 2146 to remove heat or supply heat to the fluid.

The electrode assembly 2106 is driven by an RF power source 2122. The RF power source 2122 may apply power to the conductor 2120 of the electrode assembly 2106 at a frequency such as 1 to 300 MHz. For some processes, the RF power supply 2122 provides a total RF power greater than 2 kW at a frequency of 60 MHz.

In some implementations, a heat sink 2150 (such as an aluminum plate) is attached to the top plate 2102b of the chamber body 2102. The channel 2152 may be formed through the radiator 2150 and a coolant may be circulated through the channel 2152. A heat exchanger 2154 may be connected to the channel 152 to remove heat or supply heat to the coolant.

14A-14C are schematic views of another example of a plasma reactor. In this example, the operation is the same as in FIG. 13 unless otherwise stated, and the multi-chamber processing tool 200 includes a plasma reactor 100.

The processing tool 2200 has a main body 2202 surrounding the internal space 2204. The main body 2102 may have one or more side walls 2202a, a top plate 2202b, and a bottom plate 2202c. The internal space 2204 may be cylindrical.

The processing tool 2200 includes a workpiece support 2214 (such as a base) for supporting one or more workpieces 10 (such as a plurality of workpieces). The work support 2214 has a work support surface 2214a. The workpiece support 2214 may include a workpiece support electrode 2116, and a workpiece bias voltage source 2118 may be connected to the workpiece support electrode 2116.

The space between the top of the workpiece support 2214 and the top plate 2202b may be divided into a plurality of chambers 2204a-2204d by an obstacle 2270. The obstacle 2270 may extend radially from the center of the workpiece support 2214. Although four chambers are shown, there may be two, three, or more than four chambers.

The workpiece can be rotated about the shaft 2260 by the motor 2262. As such, any workpiece 10 on the workpiece support 2214 will be sequentially carried through the chambers 2204a-2204d.

The chambers 2204a-2204d may be at least partially isolated from each other by a pump-purification system 2280. The pump-purification system 2280 may include a plurality of channels formed through the barrier 2210, which allow a purge gas (such as an inert gas, such as argon) to flow into the space between adjacent chambers, and / or direct the gas from the adjacent chambers. The space between the chambers is pumped out. For example, the pump-purification system 2280 may include a first channel 2282, such as by a pump forcing purge gas through the first channel 2282 to enter a space 2202 between the obstacle 2272 and the workpiece support 2214. Either side of the first channel 2282 (relative to the direction of movement of the workpiece support 2214) may be side-connected to the second channel 2284 and the third channel 2286. The second channel 2284 and the third channel 2286 are connected to a pump to suck gas (including Purge gas and any gas from an adjacent chamber (such as chamber 2204a). Each channel may be an elongated slot that extends generally radially.

At least one of the chambers 2204a-2204 provides a plasma chamber for the plasma reactor 2100. The plasma reactor includes a top electrode array assembly 2106 and an RF power source 2122, and may also include a fluid supply 2146 and / or a heat exchanger. The process gas may be supplied through a port 2210 positioned to the chamber 2104 along one or two obstacles 2270. In some implementations, the port 2210 is positioned only on the front side of the chamber 2104 (relative to the direction of movement of the workpiece support 2214). Alternatively or in addition, the processing gas may be supplied through a port of the side wall 2202a of the tool body 2202.

FIG. 15A illustrates an example of the electrode assembly 2106. The electrode assembly 2106 includes a dielectric top plate 2130, a plurality of conductors 2120, and a dielectric bottom plate 2132. As described above, the conductor 2120 may be arranged as a parallel linear strip that extends laterally above the workpiece support 2114. The dielectric top plate 2130 may be a ceramic material.

The dielectric backplane 2132 provides a window for RF power, ie, is substantially transparent to RF radiation at the frequency used to generate the plasma. For example, the base plate 2132 may be quartz or silicon nitride. The bottom plate can protect the plasma process and the workpiece environment from metal contamination or particle formation, otherwise it may occur if the conductor or ceramic is exposed to the plasma. The base plate 2132 may be a consumable element that is periodically replaced. The bottom plate can be relatively thin, such as 0.25mm-2mm, such as 0.5mm.

The conductor may have a width of 1-5 mm, and the interval W between the conductors 120 may be 0.5 to 3 mm. The conductor may be wider than the gap, such as about twice as wide.

The thickness T of the lower dielectric plate 2132 should be less than twice the interval W between the conductors 2120, for example, less than the interval W between the conductors. Under higher pressure, the gap between the lower dielectric plate 2132 and the upper dielectric plate 2130 should be "small", such as less than 0.5 mm, such as less than 0.25 mm, to avoid plasma from occurring behind the plate.

The conductor 2120 may be directly formed on the lower surface of the dielectric top plate surface 2130. For example, the conductor 2120 may be formed by depositing a thin layer across the bottom surface (such as electroplating, sputtering, or CVD), and then patterning by etching to form the strip line structure. The conductor may then be covered by a dielectric bottom dielectric plate 2132.

The conductor 2120 may also be embedded (ie buried) under the surface of the dielectric top plate. For example, the top plate 2130 may be a ceramic structure having a structure similar to an electrostatic wafer chuck. For buried conductors, the dielectric backplane becomes optional, but it can still be used as a dielectric cover (such as quartz) to protect the bottom surface of the top plate.

In an exemplary implementation, 45 pairs (a total of 90) of parallel conductors 2120 are deposited on a square structure ceramic top plate 2130. The conductor 2120 has a line width of 3 mm each, with an interval of 1.5 mm (therefore the conductors are arranged at a pitch of 4.5 mm). The conductor may be 400 mm long, have a vertical feedthrough line through the ceramic top plate 2130, and an electrical connection formed on the back surface at atmospheric pressure. Every other electrode is connected to the bus on one side, and the remaining (alternating) electrodes are each connected to the bus on the other side, forming two arrays. RF power at 60 MHz and 180 degrees out of phase is connected across the two arrays.

Referring to FIG. 15B, a plurality of grooves 2136 may be formed in the bottom surface 2130a of the dielectric top plate 2130, and the conductor 2120 may be fitted in the grooves. The grooves 2136 may be arranged as parallel linear stripes.

In some implementations, each conductor 2120 is part of a wire 2150. The filaments 2150 may fit into their respective grooves 2136. The filament 2150 may include a shell surrounding and protecting the conductor 2120. The filaments 2150 may be provided by various filaments 300 described with reference to FIGS. 3A-C.

Referring to FIG. 15C, in some implementations, the conductor 2120 may be provided by a conductive coating on the top plate 2130. For example, the conductor 2120 may be a strip line electrode plated on the ceramic top plate 2130. Each conductor 2120 may be a coating on one or more inner surfaces of an individual slot 2136. The space between the conductor 2120 and the bottom plate 2132 may provide a conduit 2450. The conduit 2450 may carry a fluid as described in FIG. 3A.

The plasma simulation was performed using a 2-D model to study the dependence of plasma parameters on gas pressure. The computing domain has more than two half-pairs of electrodes. Assume that the process conditions are 1450sccm Argon + 50sccm N ₂ , 6 Torr per source, and 200W per pair of half electrodes. The simulation indicates that the plasma density is usually higher in the area below the electrode. Ar + density is similar to electron density (N ₂ + density is much lower), mainly due to the high ratio of argon to N ₂ gas supply.

Specific embodiments of the invention have been described. Although this specification contains many specific implementation details, many other variations are possible. For example: · The workpiece can be moved linearly through a series of chambers, such as on a belt or linearly actuated platform, rather than a rotating platform. In addition, the workpiece may be stationary, as the workpiece support does not move relative to the wire. Connect RF power to the conductor bus at the center, end, or other location or combination of locations on the bus. • Grounding of the electrode bus can be performed at the center, end, or other location or combination of locations of the bus. · RF power supply can apply signals in RF, VHF, UHF or microwave range.

Other embodiments are within the scope of the following patent applications.

100‧‧‧ processing tools

102‧‧‧ chamber body

104‧‧‧Internal space

106‧‧‧ support

108‧‧‧Top electrode

110‧‧‧Gas distributor

112‧‧‧Gas supply

113‧‧‧Vacuum pump

114‧‧‧Workpiece support

114a‧‧‧Workpiece support surface

115‧‧‧Workpiece

116‧‧‧Workpiece support electrode

118‧‧‧ Workpiece bias voltage supply

119‧‧‧ Internal passage

120‧‧‧Indoor electrode assembly

122‧‧‧RF Power

123‧‧‧ opening

124‧‧‧balanced unbalanced converter

130‧‧‧ Dielectric Roof

132‧‧‧ bottom clearance

133‧‧‧ bottom inner space

140‧‧‧RF ground

142‧‧‧RF Bias Power Generator

144‧‧‧Impedance matching

146‧‧‧fluid supply

148‧‧‧Heat exchanger

150‧‧‧axis

152‧‧‧Actuator

154‧‧‧Drive shaft

200‧‧‧ processing tools

202‧‧‧ cylindrical body

204‧‧‧Interior space

206‧‧‧Support

208‧‧‧Top electrode

210‧‧‧Gas inlet

220‧‧‧electrode assembly

220a‧‧‧electrode assembly

220b‧‧‧electrode assembly

221‧‧‧ outer wall

221a‧‧‧Top plate

260‧‧‧Herald Station

260a‧‧‧First precursor station

270‧‧‧Radial spacer

280‧‧‧ precursor processing area

280a‧‧‧ precursor processing area

280b‧‧‧Second precursor treatment area

281‧‧‧Gas isolation zone

282‧‧‧The first pumping area

283‧‧‧purification zone

284‧‧‧Second pumping area

285a‧‧‧plasma treatment area

285b‧‧‧Second plasma treatment area

300‧‧‧ silk

302‧‧‧silk

304‧‧‧silk

310‧‧‧Conductor

320‧‧‧ cylindrical shell

330‧‧‧channel

340‧‧‧Hollow passage

400‧‧‧Indoor electrode assembly

402‧‧‧Support

410‧‧‧pitch

412‧‧‧ Plasma area

414‧‧‧ Upper plasma area

416‧‧‧ Lower plasma area

422‧‧‧RF Power

422a‧‧‧First Terminal

422b‧‧‧Second Terminal

510‧‧‧First electrode subassembly

520‧‧‧Second electrode subassembly

522‧‧‧First electrode subassembly

524‧‧‧First electrode subassembly

530‧‧‧First bus

532‧‧‧Second electrode subassembly

534‧‧‧Second electrode subassembly

540‧‧‧Second bus

550‧‧‧ Third bus

560‧‧‧ Fourth bus

580‧‧‧Adjustable impedance

590‧‧‧Feeding

592‧‧‧X-shaped current separator

600‧‧‧ electrode assembly

601‧‧‧electrode assembly

602‧‧‧ the first end

604‧‧‧second end

605‧‧‧ Bisector

610‧‧‧ Coplanar

620‧‧‧Frame

622‧‧‧ incision

624‧‧‧ wedge electrode

625‧‧‧upper

626‧‧‧ inside wall

627‧‧‧ opening

650‧‧‧Processing tools

700‧‧‧ electrode assembly

702‧‧‧electrode assembly

704‧‧‧electrode assembly

706‧‧‧electrode assembly

710‧‧‧silk

712‧‧‧ Coplanar

714‧‧‧ Coplanar

730‧‧‧First bus

732‧‧‧First bus

734‧‧‧First bus

736‧‧‧First bus

740‧‧‧Second bus

742‧‧‧Second bus

746‧‧‧Second bus

751‧‧‧second end

752‧‧‧ the first end

753‧‧‧second end

754‧‧‧ the first end

755‧‧‧second end

756‧‧‧Drive Point

800‧‧‧ electrode assembly

801‧‧‧Switching electrode system

802‧‧‧Switching electrode system

804‧‧‧Switching electrode system

806‧‧‧Switching electrode system

808‧‧‧Switching electrode system

810‧‧‧silk

811‧‧‧ the first end

812‧‧‧second end

816‧‧‧The first multiple

817‧‧‧Multiple

820‧‧‧First bus

821‧‧‧ third end

822‧‧‧Second bus

824‧‧‧Third bus

826‧‧‧ Fourth bus

828‧‧‧ Fourth bus

830‧‧‧First RF switch

831‧‧‧First terminal

832‧‧‧Second Terminal

834‧‧‧Second RF switch

836‧‧‧Third RF switch

838‧‧‧Fourth RF switch

840‧‧‧first tap

842‧‧‧Second Tap

844‧‧‧ Tap

846‧‧‧ Tap

848‧‧‧ Tap

850‧‧‧The first RF switch group

854‧‧‧Second RF switch group

856‧‧‧The third RF switch group

858‧‧‧Fourth RF switch group

860‧‧‧Sub switch

860a-860h‧‧‧Sub switch

870‧‧‧The first RF switch group

874‧‧‧Second RF switch group

876‧‧‧The third RF switch group

878‧‧‧Fourth RF switch group

900‧‧‧ Switching electrode system

902‧‧‧Switching electrode assembly

940‧‧‧ Tap

942‧‧‧Tap

1000‧‧‧ Switching electrode assembly

1010‧‧‧ Wedge-shaped electrode assembly

1030‧‧‧First RF Switch

1034‧‧‧Second RF Switch

1036‧‧‧Third RF Switch

1038‧‧‧Fourth RF switch

1040‧‧‧ Tap

1100‧‧‧PIN Diode Switch

1102‧‧‧Saturable inductor switch

1110‧‧‧PIN Diode

1120‧‧‧First capacitor

1122‧‧‧Second capacitor

1124‧‧‧First capacitor

1126‧‧‧Second capacitor

1131‧‧‧First Terminal

1132‧‧‧Second Terminal

1134‧‧‧Control terminal

1135‧‧‧Control terminal

1136‧‧‧Control signal buffer amplifier

1137‧‧‧Control signal buffer amplifier

1138‧‧‧Low-pass filter

1140‧‧‧Inductor

1150‧‧‧Inductor

1160‧‧‧Saturable inductor

1162‧‧‧Primary winding

1164‧‧‧Control winding

1200‧‧‧Frequency based switch

1200a‧‧‧The first frequency-based switch

1200b‧‧‧Second frequency-based switch

1204‧‧‧frequency switching electrode system

1220‧‧‧First capacitor

1222‧‧‧Second capacitor

1231‧‧‧First Terminal

1232‧‧‧Second Terminal

1240‧‧‧First inductor

1242‧‧‧Second inductor

1250a‧‧‧First frequency selective terminal

1250b‧‧‧Second Frequency Selective Terminal

1260‧‧‧ Tap

2100‧‧‧plasma reactor

2102‧‧‧Main body

2102a‧‧‧ sidewall

2102b‧‧‧Top plate

2102c‧‧‧Backplane

2104‧‧‧Internal space

2106‧‧‧electrode assembly

2110‧‧‧Port

2112‧‧‧Gas supply

2113‧‧‧Vacuum Pump

2114‧‧‧Workpiece support

2114a‧‧‧Workpiece support surface

2116‧‧‧Workpiece support electrode

2118‧‧‧ Workpiece bias voltage supply

2119‧‧‧Internal passage

2120‧‧‧plurality of conductors

2122‧‧‧RF Power

2130‧‧‧ Dielectric Roof

2130a‧‧‧ bottom surface

2132‧‧‧ floor

2136‧‧‧slot

2142‧‧‧RF Bias Power Generator

2144‧‧‧Impedance matching

2146‧‧‧ Fluid Supply

2148‧‧‧Heat exchanger

2150‧‧‧ Radiator

2152‧‧‧channel

2154‧‧‧Heat exchanger

2200‧‧‧Processing tools

2202‧‧‧ main body

2202a‧‧‧ sidewall

2202b‧‧‧Top plate

2202c‧‧‧ floor

2204‧‧‧Internal space

2204a-2204d‧‧‧ chamber

2210‧‧‧Barriers

2214‧‧‧Workpiece support

2214a‧‧‧Workpiece support surface

2260‧‧‧axis

2262‧‧‧Motor

2270‧‧‧ obstacle

2272‧‧‧ obstacle

2280‧‧‧Pump-Purification System

2282‧‧‧First channel

2284‧‧‧Second Channel

2286‧‧‧third channel

2450‧‧‧ Catheter

H ₁ ‧‧‧First clearance height

H ₂ ‧‧‧Second Gap Height

R ₁ ‧‧‧inner radius

R ₂ ‧‧‧ outer radius

S‧‧‧ interval

θca‧‧‧center angle

The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the present invention will be apparent from the description, drawings, and scope of patent application.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic side view of an example of a processing tool including a plasma chamber.

FIG. 2A is a schematic top view of an example of a processing tool including a plasma chamber.

2B-2C are cross-sectional side views of the processing tool of FIG. 2A along section lines B-B and C-C, respectively.

3A-3C are schematic cross-sectional perspective views of various examples of wires of an electrode assembly in a chamber.

FIG. 4A is a schematic top view of a portion of an electrode assembly in a chamber.

4B-C are cross-sectional schematic side views of an electrode assembly in a chamber with different plasma region states.

5A-D are schematic top views of various examples of electrode assembly configurations in a chamber.

FIG. 6A is a schematic top view of an example of a processing tool.

FIG. 6B is a schematic top view of an example of a wedge-shaped electrode assembly.

6C is a schematic top view of an example of a frame of a wedge-shaped electrode assembly.

6D is a cross-sectional side view of an example of a frame of a wedge-shaped electrode assembly.

FIG. 6E is a schematic top view of an example of a wedge-shaped electrode assembly.

7A-7D are conceptual diagrams of an example of an electrical configuration of a wedge-shaped electrode assembly.

FIG. 8A is a schematic top view of an example of an electrode assembly.

8B-8F are conceptual schematic diagrams of an example of an electrical configuration of a switching electrode assembly.

9A-9B are conceptual diagrams of an example of a mode-selectable switching electrode system.

FIG. 10 is a conceptual diagram of an example of a switched wedge electrode system.

FIG. 11A is a schematic diagram of an example of a PIN diode switch.

FIG. 11B is a schematic diagram of an example of a saturable inductive switch.

FIG. 12A is a schematic diagram of an example of a frequency-based switch.

12B-C are conceptual diagrams of an example of an electrical configuration of a frequency-switching electrode system.

FIG. 13 is a schematic side view of an example of a plasma reactor.

Fig. 14A is a schematic top view of another example of a plasma reactor.

14B and 14C are schematic side views of the plasma reactor of FIG. 14A along lines 14B-14B and 14C-14C, respectively.

15A-15C are schematic cross-sectional views of an electrode assembly.

The same numeral numbers in different figures represent the same elements.

Domestic hosting information (please note in order of hosting institution, date, and number) None

Information on foreign deposits (please note in order of deposit country, institution, date, and number) None

Claims (50)

A processing tool for a plasma process includes: a chamber body having an internal space, the internal space providing a plasma chamber, the chamber body having a top plate and a top plate; An opening on the opposite side, a workpiece support, which holds a workpiece such that at least a portion of a front surface of the workpiece faces the opening; an actuator, the actuator in the chamber body and A relative movement is generated between the workpiece supports, such that the opening moves laterally across the workpiece; a gas distributor that delivers a processing gas to the plasma chamber; a An electrode assembly comprising a plurality of coplanar wires, the plurality of coplanar wires extending laterally through the plasma chamber between the workpiece support and the top plate, each of the plurality of wires comprising a A conductor; and a first RF power source that provides a first RF power to the conductors of the electrode assembly to form a plasma. The processing tool according to claim 1, wherein the workpiece support is rotatable about a rotation axis, and the actuator rotates the workpiece support so that the rotation of the support carries the workpiece across the opening. The processing tool according to claim 2, wherein the plurality of coplanar wires extend across a wedge-shaped region. The processing tool according to claim 3, wherein the workpiece is completely fit in the wedge-shaped region such that the entire front surface of the workpiece is exposed to the plasma during operation. The processing tool according to claim 3, wherein the workpiece is larger than the wedge-shaped area, such that in operation, a wedge-shaped portion of the front surface of the workpiece is exposed to plasma. The processing tool according to claim 3, wherein the opening is wedge-shaped. The processing tool according to claim 3, wherein the plurality of coplanar wires include linear wires, and different wires have different lengths so as to define the wedge-shaped region. The processing tool according to claim 7, wherein the plurality of coplanar wires extend in parallel. The processing tool according to claim 7, wherein different wires are oriented at different angles. The processing tool according to claim 9, wherein the plurality of coplanar wires are oriented such that a plasma density generated in the wedge region is lower at a vertex of the wedge region than at a base of the wedge region. The processing tool according to claim 3, wherein the plurality of coplanar wires are oriented to have a longitudinal axis at a non-zero angle with respect to a moving direction of the portion of the substrate below the opening. The processing tool according to claim 11, wherein the non-zero angle is greater than 10 °. The processing tool according to claim 1, wherein a gap between the coplanar wires is sufficient to avoid a plasma region pinch between an area above and below the electrode assembly in the chamber. The processing tool according to claim 1, wherein a bottom of the chamber is opened. The processing tool according to claim 1, wherein the ends of the conductors of the plurality of coplanar wires are connected to the first RF power source by a recursive RF feed structure. The processing tool according to claim 1, wherein the opposite ends of the conductors of the plurality of coplanar wires are connected to a common bus, and the bus is connected to the first RF power source at two opposite positions. A plasma reactor includes: a chamber body having an internal space, the internal space providing a plasma chamber; a gas distributor, the gas distributor delivering a processing gas to the plasma A chamber; a pump that is coupled to the plasma chamber to evacuate the chamber; a workpiece support that holds a workpiece; an electrode assembly in the chamber that includes a plurality of wires, The plurality of wires extend laterally through the plasma chamber between a top plate of the plasma chamber and the workpiece support, and each wire includes a conductor surrounded by a cylindrical insulating shell, wherein the plurality of wires The filament comprises a first multiple filament and a second multiple filament, the second multiple filament and the first multiple filament are arranged in an alternating pattern, a first bus and a second bus, the first bus is coupled The first multifilament, the second bus is coupled to the second multifilament; an RF power source that applies an RF signal to the electrode assembly in the chamber; and at least one RF switch, the at least one RF switch Configured to controllably connect the first bus to the Each one who is electrically coupled and decoupled: i) ground, ii) RF power supply, or iii) the second bus. The plasma reactor of claim 17, wherein the at least one RF switch includes a plurality of RF switches connected in parallel between the first bus and one of the following: i) ground, ii) the RF Power supply or iii) the second bus. The plasma reactor according to claim 17, wherein the at least one RF switch is configured to controllably couple and decouple the first bus and the second bus electrically. The plasma reactor according to claim 19, wherein the at least one RF switch includes a plurality of switches connected in parallel between different pairs of positions on the first bus and the second bus to controllably control the first A bus is electrically coupled and decoupled from the second bus. The plasma reactor according to claim 17, wherein the at least one RF switch includes a first switch, the first switch is configured to controllably couple and decouple the first bus to ground, and includes at least one A second RF switch configured to controllably couple and decouple the second bus from ground. The plasma reactor according to claim 21, wherein the at least one RF switch includes a first plurality of switches connected in parallel between different positions on the first bus and ground, and the at least one second switch includes A second plurality of switches connected in parallel between different positions on the second bus and the ground. The plasma reactor according to claim 22, wherein different positions on the first bus include opposite ends of the first bus, and different positions on the second bus include opposite ends of the second bus. The plasma reactor according to claim 17, wherein the at least one RF switch includes a first switch configured to controllably electrically couple and decouple the first bus from the RF power source, and Including at least one second RF switch configured to controllably electrically couple and decouple the second bus from the RF power source. The plasma reactor according to claim 24, wherein the at least one RF switch includes a first plurality of switches connected in parallel between the different positions on the first bus and the RF power source, and the at least one second switch It includes a second plurality of switches connected in parallel between the different positions on the second bus and the RF power source. The plasma reactor according to claim 24, wherein the at least one RF switch includes a first plurality of switches connected in parallel between the different positions on the first bus and the RF power source, and the at least one second switch It includes a second plurality of switches connected in parallel between different positions on the second bus and the ground. The plasma reactor according to claim 25 or 26, wherein different positions on the first bus include opposite ends of the first bus, and different positions on the second bus include opposite ends of the second bus. The plasma reactor according to claim 17, comprising: a third bus and a fourth bus, the third bus is coupled to the first multifilament, and the fourth bus is coupled to the second multifilament, The plurality of wires have a plurality of first ends and a plurality of second ends, and the first ends of the respective wires are closer to a first side wall of the plasma chamber than the second ends of the respective wires, and the first A bus is coupled to the first ends of the first multi-filament, the second bus is coupled to the first ends of the second multi-filament, and the third bus is coupled to the first multi-filament The second ends of the filament and the fourth bus are coupled to the second ends of the second multifilament. The plasma reactor according to claim 28, wherein the at least one RF switch is configured to controllably electrically couple and decouple the first bus from the second bus, and includes at least one second RF switch, the The second RF switch is configured to controllably couple and decouple the third bus from the fourth bus. The plasma reactor of claim 28, wherein the at least one RF switch includes a first switch, the first switch is configured to controllably couple and decouple the first bus to ground, and includes at least one A second RF switch configured to controllably couple and decouple the third bus from ground. The plasma reactor of claim 28, wherein the at least one RF switch includes a first switch, the first switch is configured to controllably couple and decouple the first bus to ground, and includes at least one A second RF switch, at least one third RF switch, the second RF switch is configured to controllably couple and decouple the second bus from the RF source, and the third RF switch is configured to controllably The third bus is electrically coupled and decoupled from the ground, and includes at least one fourth RF switch configured to controllably electrically couple and decouple the fourth bus from the RF source. The plasma reactor according to claim 28, wherein the at least one RF switch includes a first switch configured to controllably electrically couple and decouple the first bus from the RF source, and Including at least one second RF switch and at least one third RF switch, the second RF switch is configured to electrically control and couple the second bus to the RF source, and the third RF switch is configured to be controllable. Electrically coupling and decoupling the third bus from the RF source and including at least one fourth RF switch configured to controllably electrically couple and decouple the fourth bus from the RF source . A plasma reactor includes: a chamber body having an internal space, the internal space providing a plasma chamber; a gas distributor, the gas distributor delivering a processing gas to the plasma A chamber; a pump that is coupled to the plasma chamber to evacuate the chamber; a workpiece support that holds a workpiece; an electrode assembly in the chamber that includes a plurality of wires, The plurality of wires laterally extend through the plasma chamber between a top plate of the plasma chamber and the workpiece support, and each wire includes a conductor surrounded by a cylindrical insulating shell, a bus, and The bus is outside the chamber and is coupled to the opposite ends of the plurality of wires; an RF power source that applies an RF signal to the electrode assembly in the chamber; and a plurality of RF switches that can be configured to control Ground electrically couples and decouples a plurality of different locations on the bus from one of: i) ground or ii) the RF power source. A plasma reactor includes: a chamber body having an internal space, the internal space providing a plasma chamber; a gas distributor, the gas distributor delivering a processing gas to the plasma A chamber; a workpiece support that holds a workpiece; an electrode assembly that includes a plurality of conductors that are spaced apart from the workpiece support in a parallel coplanar array and laterally A ground extending across the workpiece support; a first RF power source that provides a first RF power to the electrode assembly; and a dielectric backplane, the dielectric backplane being positioned between the electrode assembly and the workpiece support In between, the dielectric backplane provides an RF window between the electrode assembly and the plasma chamber. The plasma reactor according to claim 34, comprising a dielectric top plate, wherein the plurality of conductors are positioned between the dielectric top plate and the dielectric window. The plasma reactor according to claim 35, wherein the dielectric top plate is a ceramic body, and the dielectric bottom plate is quartz or silicon nitride. The plasma reactor according to claim 35, wherein a lower surface of the bottom plate has a plurality of parallel grooves, and wherein the plurality of parallel coplanar conductors are positioned in the plurality of parallel grooves. The plasma reactor according to claim 37, comprising a plurality of wires in the plurality of slots, each wire comprising a conductor and a non-metallic shell surrounding the conductor. The plasma reactor of claim 37, wherein the shell forms a conduit, and the conductor is suspended in the conduit and extends through the conduit. The plasma reactor of claim 37, wherein the conductor comprises a hollow conduit. The plasma reactor of claim 35, wherein the plurality of conductors are coated on the dielectric top plate. The plasma reactor of claim 35, wherein the plurality of conductors are embedded in the dielectric top plate. The plasma reactor according to claim 34, wherein the plurality of conductors includes a first multiple conductor and a second multiple conductor, the second multiple conductors are arranged in an alternating pattern with the first multiple conductor, and The RF power supply is configured to apply a first RF input signal to the first multiple conductor and a second RF input signal to the second multiple conductor. The plasma reactor according to claim 43, wherein the RF power source is configured to generate the first RF signal and the second RF signal at the same frequency. The plasma reactor of claim 44, wherein the RF power source is configured to provide an adjustable phase difference between the first RF signal and the second RF signal. The plasma reactor according to claim 43, wherein the plurality of conductors have a plurality of first ends on a first side of the plasma chamber, and have a second end on an opposite second side of the plasma chamber Plural second ends. The plasma reactor of claim 46, wherein the RF power source is configured to apply the first RF input signal to the first end of the first multi-conductor, and apply the second RF input signal to the The second end of the second multiple conductor. The plasma reactor of claim 47, wherein the second end of the first multiple conductor is floating and the first end of the second multiple conductor is floating. The plasma reactor of claim 47, wherein the first ends of the first multiple conductor are connected to a first common bus, and the second ends of the second multiple conductor are connected to a first Two shared buses. The plasma reactor of claim 47, wherein the second ends of the first multifilament are grounded, and the first ends of the second multifilament are grounded.