JP2008016476A - Semiconductor manufacturing equipment - Google Patents

Abstract

Uniform plasma is generated over the entire electrode group.
A wafer is mounted on each of a plurality of stages of susceptor electrodes arranged in a processing chamber, and AC power is supplied by an AC power supply device connected to the plurality of stages of susceptor electrodes to plasma. 51, a batch type plasma processing apparatus that collectively plasma-treats a group of wafers placed on the plurality of stages of susceptor electrodes 50. The susceptor electrode 50 group is divided into a plurality of regions, and an AC power supply apparatus 60 is provided. The first rotary switch 70, the second rotary switch 80, and the switch changer 90 that operates the first rotary switch 70 and the second rotary switch 80 in synchronization are provided. The application timing of the discharge start voltage to the susceptor electrode group is sequentially switched for each divided region of the susceptor electrode group. Since the discharge start voltage can be appropriately applied for each divided region, uniform plasma can be generated in all susceptor electrode groups.
[Selection] Figure 3

Description

  The present invention relates to a semiconductor manufacturing apparatus and, for example, relates to an apparatus that can be effectively used for performing plasma processing on a semiconductor wafer (hereinafter referred to as a wafer) on which a semiconductor integrated circuit device (hereinafter referred to as an IC) is manufactured.

  In a method of manufacturing an IC, a plasma processing apparatus that uses plasma to form a thin film on a wafer, modify the surface, or etch the surface is used as a pair of susceptor electrodes between a pair of electrode columns. With each wafer mounted on each susceptor electrode, AC power is supplied between all susceptor electrodes, so that plasma processing is performed on each wafer at once. There is a batch type plasma processing apparatus configured to be applied. For example, see Patent Document 1.

JP 2006-49367 A

  However, in the above-described batch type plasma processing apparatus, if it is not possible to simultaneously apply a discharge start voltage between all susceptor electrodes, uniform plasma cannot be generated between all susceptor electrodes. It has been clarified by the present inventors that there is a problem that the plasma processing state becomes uneven between wafers.

  An object of the present invention is to provide a semiconductor manufacturing apparatus capable of generating uniform plasma over the entire electrode group.

Representative inventions disclosed in the present application are as follows.
(1) A substrate is disposed on each of the plurality of stages of electrodes disposed in the processing chamber, plasma is generated by supplying AC power to the plurality of stages of electrodes, and the substrates of the plurality of stages of electrodes are collectively collected. In semiconductor manufacturing equipment for plasma processing,
2. A semiconductor manufacturing apparatus, comprising: switching means for sequentially switching the supply timing of the AC power to the electrode group for each stage of the electrode group.
(2) The semiconductor manufacturing apparatus according to (1), wherein the switching unit is configured to switch every pair or a plurality of pairs of electrodes facing vertically.
(3) A substrate is disposed on each of the plurality of stages of electrodes disposed in the processing chamber, plasma is generated by supplying AC power to the plurality of stages of electrodes, and the substrates of the plurality of stages of electrodes are collectively collected. In a method for manufacturing a semiconductor device for plasma processing,
A method of manufacturing a semiconductor device, wherein the supply timing of the AC power to the electrode group is sequentially switched for each stage of the electrode group.

  According to (1), since the discharge start voltage can be appropriately applied between all the electrodes, uniform plasma can be generated over the entire electrode group.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In this embodiment, a semiconductor manufacturing apparatus according to the present invention is a batch type vertical hot wall type plasma processing apparatus (hereinafter referred to as a batch type plasma processing apparatus) that performs various plasma processes on a wafer in an IC manufacturing method. It is configured as.
In the present embodiment, for the sake of convenience, the case where the number of wafers in one batch process is 16 has been described. However, in practice, batches of about 5 to 150 can be handled. To do.

As shown in FIG. 1, in the batch type plasma processing apparatus 10 according to the present embodiment, an open cassette (hereinafter, referred to as a wafer carrier for storing and transporting the wafer 1 as a substrate to be processed) is used. 2) is used.
The batch type plasma processing apparatus 10 includes a housing 11. A front maintenance port 12 for maintenance is opened at the lower part of the front wall of the housing 11, and the front maintenance door 13 is built to open and close the front maintenance door 13.
A cassette loading / unloading port 14 is opened in the front maintenance door 13 so as to communicate between the inside and outside of the housing 11, and the cassette loading / unloading port 14 is opened and closed by a front shutter 15.

A cassette stage 16 is installed inside the casing 11 of the cassette loading / unloading port 14. The cassette 2 is loaded onto the cassette stage 16 by an in-process transfer device (not shown) and is also unloaded from the cassette stage 16.
The in-process transfer apparatus places the cassette 2 on the cassette stage 16 so that the wafer 1 in the cassette 2 is in a vertical posture and the wafer loading / unloading port of the cassette 2 faces upward.
The cassette stage 16 rotates the cassette 2 clockwise 90 degrees to the rear of the casing 11 so that the wafer 1 in the cassette 2 is in a horizontal posture and the wafer loading / unloading port of the cassette 2 faces the rear of the casing 11.

A cassette shelf 17 is installed at a substantially central portion in the front-rear direction in the housing 11. The cassette shelf 17 is provided with a plurality of stages of transfer shelves 18 in which a plurality of cassettes 2 are stored, and the cassette shelf 17 is configured to store a plurality of cassettes 2 in a plurality of stages and a plurality of rows.
Further, a spare cassette shelf 19 is provided above the cassette stage 16, and the spare cassette shelf 19 is configured to preliminarily store the cassette 2.

  A cassette carrying device 20 is installed between the cassette stage 16 and the cassette shelf 17. The cassette carrying device 20 includes a cassette elevator 20a that can be moved up and down while holding the cassette 2, and a cassette carrying mechanism 20b as a carrying mechanism. By the continuous operation of the cassette elevator 20a and the cassette carrying mechanism 20b, The cassette 2 is transported among the stage 16, the cassette shelf 17 and the spare cassette shelf 19.

A wafer transfer mechanism 21 is installed behind the cassette shelf 17. The wafer transfer mechanism 21 includes a wafer transfer device elevator 22 and a wafer transfer device 23 that is moved up and down by the wafer transfer device elevator 22.
The wafer transfer device elevator 22 is installed at the right end of the housing 11.
The wafer transfer device 23 is configured to move the tweezer holder 24 in a two-dimensional direction. In the tweezer holder 24, a plurality of (in this embodiment, five) tweezers 25 are arranged at equal intervals in the vertical direction. Arranged and held horizontally. However, the topmost tweezers 25 of the five tweezers 25 are configured to be able to advance and retreat independently.

As shown in FIG. 1, a clean unit 29 composed of a fan and a dustproof filter is installed above the cassette shelf 17. The clean unit 29 supplies clean air, which is a purified atmosphere, to the housing 11. It is comprised so that it may distribute | circulate inside.
For the sake of convenience, although not shown, a clean unit is also installed at the left end of the housing 11 on the side opposite to the wafer transfer apparatus elevator 22 side. It is configured to be distributed in space.

As shown in FIGS. 1 and 2, a processing furnace 30 is vertically installed on the upper rear side of the casing 11.
As shown in FIG. 2, the processing furnace 30 includes a process tube 31 that forms a processing chamber 32. The process tube 31 is made of a dielectric material such as quartz and is formed in a cylindrical shape with one end opened and the other end closed. The process tube 31 is vertically arranged so that the center line is vertical and is fixedly supported. ing.
The cylindrical hollow portion of the process tube 31 forms a processing chamber 32 in which a plurality of wafers 1 are accommodated, and the inner diameter of the process tube 31 is set to be larger than the maximum outer diameter of the wafer 1 to be handled.

A manifold 33 is in contact with the lower end surface of the process tube 31, and the manifold 33 is formed in a cylindrical shape having a flange projecting radially outward at both upper and lower ends using a dielectric. The manifold 33 is detachably attached to the process tube 31 for maintenance and inspection work and cleaning work on the process tube 31.
The manifold 33 is supported by the housing 11 so that the process tube 31 is installed vertically.
A lower end opening of the manifold 33 forms a furnace port 34 for taking in and out the wafer 1. The furnace port 34 is normally closed by a furnace port shutter 35.

  One end of an exhaust pipe 36 is connected to the side wall of the manifold 33, and the other end of the exhaust pipe 36 is connected to an exhaust device (not shown) so that the processing chamber 32 can be exhausted.

A gas supply pipe 37 for supplying a processing gas is vertically provided at a position different from the exhaust pipe 36 of the manifold 33 (position opposite to 180 degrees in the illustrated example), and the gas supply pipe 37 is made of a dielectric. Used to form an elongated circular pipe.
A plurality of air outlets 38 are arranged in the gas supply pipe 37 so as to be arranged in the vertical direction. The number of blowout ports 38 matches the number of wafers 1 to be processed, and the height position of each blowout port 38 is set so as to face the space between adjacent wafers 1, 1 above and below. .

  A heater 39 for uniformly heating the entire processing chamber 32 is provided outside the process tube 31 in a concentric circle so as to surround the periphery of the process tube 31. It is in the state where it was installed.

As shown in FIG. 1, a boat elevator 40 is installed in the casing 11 immediately below the processing furnace 30, and the arm 41 of the boat elevator 40 has a seal that closes the furnace port 34 during processing. The cap 42 is supported horizontally.
The seal cap 42 is formed in a disk shape substantially equal to the outer diameter of the manifold 33, and is configured to be hermetically sealed and closed by being raised by the boat elevator 40.

On the seal cap 42, a boat (conveying jig) 43 that holds a plurality of wafers 1 and carries it in / out of the processing chamber 32 is vertically supported and supported.
The boat 43 includes a pair of upper and lower end plates 44 and 45 and a plurality of (four in the present embodiment) holding pillars 46 that are provided between the both end plates 44 and 45 and arranged vertically. Yes.
The holding column 46 is configured to also serve as a feeder that supplies power to a susceptor electrode described later. Each holding column (hereinafter referred to as an electrode column) 46 is formed using silicon carbide (SiC) as a conductive material that does not become a metal contamination source of the wafer 1.

In each electrode support 46, a plurality of susceptor electrodes 50 (16 in the present embodiment) are arranged at equal intervals in the vertical direction and held horizontally.
The distance between the upper and lower susceptor electrodes 50, 50 is determined in consideration of the dimensions necessary for the transfer of the wafer 1 by the tweezer 25 of the wafer transfer device 23 and the action of plasma processing described later.

The susceptor electrode 50 is formed in a circular (see FIG. 1) flat plate shape using silicon carbide as a conductive material that does not contaminate the wafer 1 with metal, and the outer diameter is larger than the outer diameter of the wafer 1. It is set (see FIG. 4).
Note that silicon (Si) may be used as another material for the electrode support 46 and the susceptor electrode 50.

As shown in FIG. 3, the susceptor electrodes 50 are electrically connected to an AC power supply device 60 including an AC power supply 61, a matching unit 62, a matching unit side energization circuit 63, and an AC power supply side energization circuit 64. ing.
The AC power supply device 60 includes a first rotary switch (hereinafter referred to as a first switch) 70, a second rotary switch (hereinafter referred to as a second switch) 80, a first switch 70, and a second switch as switching means. And a switch changer 90 that operates in synchronization with the control unit 80.

The first switch 70 is provided in parallel with the matching unit side energization circuit 63 and includes one fixed side contact 71, four movable side contacts 72, 73, 74, 75 and one movable iron piece 76. ing.
The four movable contact points 72 to 75 are arranged at equal intervals on a concentric circle with the fixed contact point 71 as the center.
One end of the movable iron piece 76 is electrically connected to the fixed-side contact 71 and is configured to be rotated in one direction around the fixed-side contact 71 by the switch switch 90. The other end of the movable iron piece 76 is adapted to be switched by sliding the four movable side contacts 72 to 75 with rotation.

The second switch 80 is provided in parallel with the AC power supply side energization circuit 64, and includes one fixed contact 81, four movable contacts 82, 83, 84, 85, and one movable iron piece 86. Yes.
The four movable contacts 82 to 85 are arranged at equal intervals on a concentric circle with the fixed contact 81 as the center.
One end of the movable iron piece 86 is electrically connected to the fixed-side contact 81 and is configured to be rotated in one direction around the fixed-side contact 81 by the switch switch 90. The other end portion of the movable iron piece 86 is adapted to be switched by sliding the four movable side contacts 82 to 85 with rotation.

  The switch changer 90 is configured to synchronize and rotate the movable iron piece 76 of the first switch 70 and the movable iron piece 86 of the second switch 80 to synchronize the first switch 70 and the second switch 80. Has been.

A matching unit side energization circuit 63 is connected to the fixed side contact 71 of the first switch 70, and an AC power source side energization circuit 64 is connected to the fixed side contact 81 of the second switch 80.
The first-stage susceptor electrode 50 and the third-stage susceptor electrode 50 are connected to the electric circuit F1 connected to the first movable-side contact 72 of the first switch 70. The fifth-stage susceptor electrode 50 and the seventh-stage susceptor electrode 50 are connected to the electric circuit F <b> 2 connected to the second movable contact 73 of the first switch 70. The ninth-stage susceptor electrode 50 and the eleventh-stage susceptor electrode 50 are connected to the electric circuit F3 connected to the third movable-side contact 74 of the first switch 70. The thirteenth stage susceptor electrode 50 and the fifteenth stage susceptor electrode 50 are connected to the electric circuit F4 connected to the fourth movable contact 75 of the first switch 70.

  The second-stage susceptor electrode 50 and the fourth-stage susceptor electrode 50 are connected to the electric circuit S1 connected to the first movable contact 82 of the second switch 80. The sixth-stage susceptor electrode 50 and the eighth-stage susceptor electrode 50 are connected to the electric circuit S2 connected to the second movable contact 83 of the second switch 80. The tenth-stage susceptor electrode 50 and the twelfth-stage susceptor electrode 50 are connected to the electric circuit S3 connected to the third movable contact 84 of the second switch 80. A fourteenth stage susceptor electrode 50 and a sixteenth stage susceptor electrode 50 are connected to the electric circuit S4 connected to the fourth movable contact 85 of the second switch 80.

The pair of susceptor electrodes 50 and 50 adjacent to each other in the odd-numbered stage and the even-numbered stage constitute a pair of parallel plate electrodes. These are connected in parallel by the side energization circuit 64.
For example, the first-stage susceptor electrode 50 and the second-stage susceptor electrode 50 constitute a first set of parallel plate electrodes, and the third-stage susceptor electrode 50 and the fourth-stage susceptor electrode 50 are a second set. The parallel plate electrode is configured.

Between the first set of susceptor electrodes 50, 50 and between the second set of susceptor electrodes 50, 50, the electric circuit F 1 connected to the first movable contact 72 of the first switch 70 and the second switch 80 AC power is supplied by the electric circuit S1 connected to the one movable contact 82.
Between the third set of susceptor electrodes 50, 50 and between the fourth set of susceptor electrodes 50, 50, the electric circuit F 2 connected to the second movable contact 73 of the first switch 70 and the second switch 80 AC power is supplied by the electric circuit S2 connected to the second movable contact 83.
Between the fifth set of susceptor electrodes 50, 50 and between the sixth set of susceptor electrodes 50, 50, the electric circuit F 3 connected to the third movable-side contact 74 of the first switch 70 and the second switch 80 AC power is supplied by the electric circuit S3 connected to the three movable contacts 84.
Between the seventh set of susceptor electrodes 50, 50 and between the eighth set of susceptor electrodes 50, 50, the electric circuit F 4 connected to the fourth movable contact 75 of the first switch 70 and the second switch 80 AC power is supplied by the electric circuit S4 connected to the four movable contacts 85.
As the AC power, an AC power source having a low frequency from several kHz to a high frequency such as 13.56 MHz is used.

  Next, the plasma processing method in the manufacturing method of IC by the batch type plasma processing apparatus 10 which concerns on the said structure is demonstrated.

As shown in FIG. 1, the cassette loading / unloading port 14 is opened by the front shutter 15 before the cassette 2 is supplied to the cassette stage 16.
Thereafter, the cassette 2 is loaded from the cassette loading / unloading port 14 and mounted on the cassette stage 16 so that the wafer 1 is in a vertical posture and the wafer loading / unloading port of the cassette 2 faces upward.
Thereafter, the cassette 2 is moved 90 degrees clockwise and vertically to the rear of the housing 11 so that the wafer 1 in the cassette 2 is placed in a horizontal posture by the cassette stage 16 and the wafer loading / unloading port of the cassette 2 faces the rear of the housing 11. Rotated degrees.
Next, the cassette 2 is automatically transported and delivered by the cassette transport device 20 to the designated shelf position of the cassette shelf 17 or the spare cassette shelf 19.

After being temporarily stored, the cassette 2 is transferred from the cassette shelf 17 to the spare cassette shelf 19 to the transfer shelf 18 by the cassette transfer device 20 or directly transferred to the transfer shelf 18.
When the cassette 2 is transferred to the transfer shelf 18, the wafer transfer device 23 picks up the five wafers 1 in the cassette 2 at a time through the wafer loading / unloading port of the cassette 2 by the five tweezers 25, and the wafers. 1 is transferred from the cassette 2 to the boat 43, and five wafers 1 are transferred from the five tweezers 25 onto the five-stage susceptor electrode 50 of the boat 43 at a time.
When the five wafers 1 are transferred onto the five-stage susceptor electrode 50 at a time, the wafer transfer device 23 returns the tweezers 25 to the cassette 2, and the next five wafers 1 are transferred at once by the five tweezers 25. Pick up.
By repeating the above operation, the wafer transfer device 23 sequentially transfers the wafers 1 on the susceptor electrode 50 group up to the lowest level (sixteenth level in this embodiment). go.
Finally, when the wafer 1 remains, the necessary wafer 1 is transferred to the susceptor electrode 50 by using a tweezer 25 that can move independently.

The boat 43 on which the wafer 1 is transferred onto the susceptor electrode 50 at a predetermined stage is lifted by the boat elevator 40 and loaded into the processing chamber 32 of the processing furnace 30 as shown in FIG. 4 (boat loading). )
When the boat 43 reaches the upper limit, the seal cap 42 closes the furnace port 34 in a sealed state, so that the processing chamber 32 is hermetically closed.
When closed hermetically, the processing chamber 32 is exhausted by the exhaust pipe 36 and heated to a predetermined temperature (for example, about 800 ° C.) by the heater 39.
At this time, since the heater 39 has a hot-wall structure, the temperature of the processing chamber 32 is maintained uniformly throughout, and therefore the temperature distribution of the group of wafers held in the boat 43 is uniform over the entire length. At the same time, the temperature distribution in the surface of each wafer 1 is uniform and the same.

  After the temperature in the processing chamber 32 reaches a preset value and stabilizes, the processing gas 48 is supplied into the processing chamber 32 from the gas supply pipe 37, and the pressure in the processing chamber 32 becomes a preset value. When reaching, the AC power supply device 60 supplies AC power having a phase difference of 180 degrees to the susceptor electrodes 50 of each stage.

As shown in FIG. 4, uniform and flat plasma 51 is generated on the entire bottom surface of the susceptor electrode 50 facing the active area side of the wafer 1.
Since this uniform and flat plasma 51 is generated on the active area side of the wafer 1, the main surface on the active area side of the wafer 1 is uniformly subjected to plasma processing over the entire surface.

The processing gas 48 supplied to the gas supply pipe 37 is blown out from the outlets 38 to the upper space of the wafer 1 at each stage, and the reaction is activated by the plasma 51 generated on the lower surface of each susceptor electrode 50. Become.
Particles activated by the susceptor electrode 50 at each stage (hereinafter referred to as active particles) come into contact with the main surface on the active area side of the wafer 1 placed on the susceptor electrode 50 at each stage and contact the wafer 1. Apply plasma treatment.
At this time, as described above, the temperature distribution of the wafer 1 is maintained uniformly over the entire length of the boat 43 and within the wafer surface, and the contact distribution of the active particles with the wafer 1 by the uniform and flat plasma 51 is different in each stage. Since the wafers 1 are equal and uniform in the wafer surface of the wafers 1 of the respective stages, the plasma processing state of the wafers 1 by the plasma reaction of the active particles is between the wafers 1 of the respective stages and the wafers of the respective stages. It becomes a uniform state within one wafer surface.

  When the processing time set in advance elapses, the supply of the processing gas 48, the heating of the heater 39, the application of AC power, the exhaust of the exhaust pipe 36, etc. are stopped, and then the seal cap 42 is lowered by the boat elevator 40. As a result, the furnace port 34 is opened and the boat 43 is unloaded from the furnace port 34 to the outside of the processing chamber 32 (boat unloading).

The wafer 1 carried out of the processing chamber 32 is stored in the cassette 2 by a procedure reverse to the operation of the wafer transfer device 23 described above.
By repeating the above operation, a plurality of wafers 1 are batch processed.

By the way, in the above batch processing, since about 100 wafers are arranged in parallel, a large-capacity capacitor is equivalently inserted into the AC power supply device 60 which is a plasma generation circuit.
Specifically, considering a case where 100 wafers having a diameter of 300 mm are installed, one side of a parallel plate capacitor is a square capacitor of 2.7 m. Since the capacitance of the parallel plate capacitor is proportional to the area of the capacitor, for example, when the distance between the parallel plates is 10 mm, it becomes 6.24 × 10 ⁻⁹ F.
When the capacitance increases in this way, the impedance decreases, and if it is attempted to apply a voltage for starting discharge to that portion, it is necessary to input a large amount of power.
For example, when considering a discharge at a distance between electrodes of 10 mm and a pressure in the processing chamber of about 100 Pa, according to Paschen's law, the discharge starts by applying a voltage of 400 to 500 V or more to the portion. Become. When the internal resistance is 50Ω, it is necessary to apply a voltage of 10,000 V or more to the whole, and the power also increases.
If 100 wafers are installed at an interval of 10 mm, an area close to 1 m is discharged at a time. If the discharge start voltage cannot be applied to all electrodes at the same time, a region where the discharge does not start occurs, causing discharge spots and the like, so that uniform plasma cannot be generated between all the electrodes. There is a fear.

  Therefore, in this embodiment, the 16 susceptor electrodes 50 are divided into eight regions (zones), and the discharge start voltage is divided into eight regions by the first switch 70, the second switch 80, and the switch switch 90. By sequentially supplying the time intervals, discharge is surely generated in all eight regions, and uniform plasma is generated between all the susceptor electrodes 50.

  Hereinafter, the plasma generation operation in the batch type plasma processing apparatus 10 according to the present embodiment will be described with reference to FIG.

When the plasma generation conditions are established in the plasma processing method described above, the AC power supply device 60 sets the discharge start voltage (for example, 400 to 500 V) between the first set of susceptor electrodes 50 and 50 and the second set of susceptor electrodes 50, The voltage is applied through the electric circuit F 1 connected to the first movable side contact 72 of the first switch 70 and the electric circuit S 1 connected to the first movable side contact 82 of the second switch 80.
Since the electrostatic capacity at this time is smaller than the case where the discharge of 16 wafers is started simultaneously, the discharge between the first set of susceptor electrodes 50 and 50 and the discharge between the second set of susceptor electrodes 50 and 50 are performed. Starts reliably, and plasma 51 (see FIG. 4) is properly generated between the first set of susceptor electrodes 50 and 50 and between the second set of susceptor electrodes 50 and 50.
When plasma 51 is generated between the first set of susceptor electrodes 50 and 50 and between the second set of susceptor electrodes 50 and 50, a closed circuit is provided between the matching unit side energization circuit 63 and the AC power supply side energization circuit 64. Is formed via the plasma 51, the plasma is stably maintained by a voltage equal to or lower than the discharge start voltage.

When a preset switching timing time elapses, the switch switch 90 switches the first switch 70 and the second switch 80 to the second movable side contacts 73 and 83.
When the first switch 70 and the second switch 80 are switched to the second movable contact 73, 83, the AC power supply device 60 changes the discharge start voltage between the third set of susceptor electrodes 50, 50 and the fourth set of susceptors. Application is made between the electrodes 50, 50 through an electric circuit F 2 connected to the second movable contact 73 and an electric circuit S 2 connected to the second movable contact 83.
Since the electrostatic capacity at this time is also small, the discharge between the third set of susceptor electrodes 50 and 50 and the discharge between the fourth set of susceptor electrodes 50 and 50 are surely started, and the plasma 51 (see FIG. 4) is generated. Properly generated.
When plasma 51 is generated between the third set of susceptor electrodes 50 and 50 and between the fourth set of susceptor electrodes 50 and 50, a closed circuit is also formed between the matching unit side energizing circuit 63 and the AC power source side energizing circuit 64. Is formed via the plasma 51, the plasma is stably maintained by a voltage equal to or lower than the discharge start voltage.

Thereafter, the switch changer 90 sequentially switches the first switch 70 and the second switch 80 to the third movable side contacts 74 and 84 and the fourth movable side contacts 75 and 85, so that the fifth set of susceptor electrodes 50 is obtained. , 50, between the sixth set of susceptor electrodes 50, 50, between the seventh set of susceptor electrodes 50, 50 and between the eighth set of susceptor electrodes 50, 50, the plasma 51 is reliably generated and stable. Maintained.
Note that the switching timing of the switch varies depending on parameters such as the number of electrodes connected to the movable contact, the discharge start voltage, the distance between the electrodes, and the pressure in the processing chamber. It is desirable to obtain and set appropriately.
Further, in order to use a high voltage generated when the switch is switched, the switch may be set to switch at a high speed.

  According to the embodiment, the following effects can be obtained.

1) Dividing a plurality of susceptor electrodes into a plurality of regions, and supplying a discharge start voltage to the plurality of regions sequentially by dividing the time by a first switch, a second switch, and a switch changer, thereby providing a plurality of regions Since discharge can be reliably generated in all and uniform plasma can be generated between all susceptor electrodes, uniform plasma treatment can be performed between wafers in a batch.

2) Dividing a plurality of susceptor electrodes into a plurality of regions, and supplying the discharge start voltage to the plurality of regions sequentially by dividing the time by the first switch, the second switch, and the switch changer, the discharge start voltage Can be set low, so that a large amount of electric power is not required.

  Needless to say, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.

  For example, the switching means is not limited to mechanical engineering by the first switch, the second switch, and the switch, but may be configured by electrical engineering by a triac, power IC, etc., or by thermal engineering by bimetal or the like. You may comprise.

  In the above embodiment, 16 susceptor electrodes have been described for convenience of explanation and illustration, but 50 to 150 susceptor electrodes are actually used.

In the above-described embodiment, the case where the susceptor electrode group is divided into eight regions (zones) has been described for convenience of explanation and illustration, but the number of divisions is not limited thereto.
Ideally, it is desirable to divide each pair of susceptor electrodes.
However, for example, in the case of 100 susceptor electrodes, it is divided into 50 regions, and the discharge start voltage is applied between the first set of susceptor electrodes and the discharge start voltage is applied between the last set of susceptor electrodes. Since a large time difference occurs, the time for applying the discharge start voltage to each group becomes relatively short, and the switching means becomes complicated, the actual number of wafers is 10 sheets. It is realistic to divide each area.

  The electrode is not limited to a susceptor electrode structure that also serves as a susceptor (support) that supports the wafer in contact with the wafer, but may be configured as a pair of parallel plate electrode structures in which the wafer is disposed in a non-contact manner. .

  The present invention can be used for all semiconductor manufacturing apparatuses that perform plasma processing such as plasma CVD and dry etching.

  Further, the substrate to be processed is not limited to a wafer, but may be a photomask, a printed wiring board, a liquid crystal panel, a compact disk, a magnetic disk, or the like.

1 is a partially omitted perspective view showing a batch type plasma processing apparatus according to an embodiment of the present invention. It is front sectional drawing which follows the II-II line of FIG. It is a circuit diagram which shows the supply circuit of alternating current power. It is a partially omitted front sectional view showing a plasma processing step.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Wafer (substrate), 2 ... Cassette, 10 ... Batch type plasma processing apparatus (semiconductor manufacturing apparatus), 11 ... Housing, 12 ... Front maintenance port, 13 ... Front maintenance door, 14 ... Cassette loading / unloading port, 15 ... Front shutter, 16 ... cassette stage, 17 ... cassette shelf, 18 ... transfer shelf, 19 ... spare cassette shelf, 20 ... cassette transfer device, 20a ... cassette elevator, 20b ... cassette transfer mechanism, 21 ... wafer transfer mechanism, 22 ... Wafer transfer device elevator, 23 ... Wafer transfer device, 24 ... Tweezer holder, 25 ... Tweezer, 29 ... Clean unit, 30 ... Processing furnace, 31 ... Process tube, 32 ... Processing chamber, 33 ... Manifold, 34 ... Furnace port 35 ... Furnace port shutter, 36 ... Exhaust pipe, 37 ... Gas supply pipe, 38 ... Air outlet, 39 ... Heater, 40 ... Baud Elevator, 41 ... arm, 42 ... seal cap, 43 ... boat (conveying jig), 44, 45 ... end plate, 46 ... electrode support, 48 ... processing gas, 50 ... susceptor electrode (electrode), 51 ... plasma, 60 DESCRIPTION OF SYMBOLS ... AC power supply device 61 ... AC power supply 62 ... Matching unit 63 ... Matching unit side energization circuit 64 ... AC power source side energization circuit 70 ... First rotary switch (switching means) 71 ... Fixed side contact 72 73, 74, 75 ... movable side contact, 76 ... movable iron piece, 80 ... second rotary switch (switching means), 81 ... fixed side contact, 82, 83, 84, 85 ... movable side contact, 86 ... movable iron piece, 90: Switch selector (switching means).

Claims (1)

A substrate is disposed on each of the plurality of stages of electrodes disposed in the processing chamber, plasma is generated by supplying AC power to the plurality of stages of electrodes, and the respective substrates of the plurality of stages of electrodes are subjected to plasma processing collectively. In semiconductor manufacturing equipment,
2. A semiconductor manufacturing apparatus, comprising: switching means for sequentially switching the supply timing of the AC power to the electrode group for each stage of the electrode group.

Images