CN103201407A - Plasma apparatus - Google Patents

Abstract

Gas piping (19-21) supplies an Ar gas to the inside of a vacuum container (1). A high frequency power supply (12) makes a high frequency current flow to planar electrodes (2, 3) from one end of each of the electrodes (2, 3). Consequently, plasma is generated in the vicinity of the surfaces of target members (4, 5) due to inductive coupling. A low frequency power supply (16) applies alternating current voltages to the electrodes (2, 3). Consequently, electrons in the plasma flow into a target member (one of the target members (4, 5)) disposed in contact with a positively biased electrode (one of the electrodes (2, 3)), and positive ions in the plasma flow into a target member (the other one of the target members (4, 5)) disposed in contact with a negatively biased electrode (the other one of the electrodes (2, 3)). Then, the electrons and the positive ions in the plasma stay between the electrodes (2, 3) and in the vicinity of the surfaces of the target members (4, 5).

Description

plasma device

technical field

The present invention relates to a plasma device.

Background technique

A conventional plasma device includes a target made of a dielectric, a magnet, a high-frequency power supply, and a matching circuit (Non-Patent Document 1). In order to arrange a magnetic field on the surface of the target, a magnet is provided on the back surface of the target. A high frequency power supply is connected to the target. The matching circuit is connected between the high-frequency power supply and the target. The target is water cooled.

Furthermore, the substrate to be processed and a substrate holder (holder) are arranged at positions facing the target. In addition, depending on the purpose, the substrate to be processed and the substrate holder are connected to a low-frequency power supply or a DC power supply with a frequency lower than that of the high-frequency power supply connected to the target to apply a bias voltage.

The operation of the conventional plasma apparatus is as follows. Plasma is generated by capacitive coupling between the target, the vacuum vessel, and the substrate by applying a high-frequency voltage to the target. In general, capacitively coupled high-frequency discharge generates high-frequency reflection by the plasma as the plasma density increases, and as a result, high-frequency power does not enter the plasma efficiently, making it difficult to further increase the density.

Then, a magnetic field is formed near the surface of the target, electrons in the plasma are captured by the magnetic field, and magnetron discharge is performed to achieve high density.

The electrons in the plasma move back and forth between the target and the substrate or vacuum container through the alternating electric field generated by the high-frequency voltage applied to the target. The dielectric material that is the target material is charged, and as a result, a negative DC bias voltage and a high-frequency voltage are superimposed on the surface of the target.

Positive ions in the plasma are introduced by this negatively charged DC bias, and are incident on the surface of the target with high energy. Thus, the target surface is sputtered. In addition, at the same time, on the surface of the target, it is necessary to cool the target as the temperature rises in order to stabilize the target surface and to suppress a rise in the temperature of the opposing substrate due to radiation from the target.

Particles sputtered on the surface of the target fly to the facing substrate, forming a film composed of the same elemental composition as the constituent elements of the target. Since the target is negatively charged and the substrate and the vacuum vessel are relatively positively charged, electrons, which are negatively charged particles, also fly to the substrate surface at the same time as the sputtered particles fly to the substrate surface.

The plasma on the target surface produces strong inhomogeneity along with the magnetic field distribution. In general, in the case of a circular target, a structure in which magnetic force lines are arranged between the center and the periphery of the target is formed, and as a result, annular high-density plasma is generated, and sputtering of the target also occurs in an annular shape.

prior art literature

non-patent literature

Non-Patent Document 1: Yuichi Oishi, Daishi Kobayashi, Tatsutoku Isobe, Makoto Arai, Junya Kiyota, Takashi Komatsu, Akatsuki Ishibashi, Kazuya Saito, Shigemitsu Sato, and Masasuke Sudai, "TFT suitable for large substrates Sputtering device and its cathode", 2006 ULVAC TECHNICAL JOURNAL No. 64.

Contents of the invention

The problem to be solved by the invention

However, in the conventional plasma device, since the sputtering particles fly to the substrate surface, electrons as negatively charged particles also fly to the substrate surface, so there are electrons with energy that heat the substrate and cause The problem of damaged membranes.

Therefore, the present invention was made to solve the above problems, and an object of the present invention is to provide a plasma device capable of suppressing a temperature rise of a substrate and suppressing damage to a film formed on the substrate.

means of solving problems

According to an embodiment of the present invention, a plasma device includes a plurality of electrodes, a plurality of target members, and first and second power sources. The plurality of electrodes are arranged in a planar shape, and each has a rectangular planar shape. The plurality of target members are provided corresponding to the plurality of electrodes, are each made of a dielectric, and are arranged in contact with the surface of the corresponding electrode on the substrate side. The first power supply flows a high-frequency current having a first frequency from one end of the plurality of electrodes to the plurality of electrodes. The second power supply applies the voltage having the second frequency to the plurality of electrodes so as to alternately apply the voltage having the second frequency lower than the first frequency to the two electrodes.

The effect of the invention

In the plasma apparatus according to the embodiment of the present invention, a high-frequency current is supplied to a plurality of electrodes by a first power supply, and plasma is generated by inductive coupling in the vicinity of the surface of a plurality of target members arranged in contact with the plurality of electrodes. Next, a voltage with a second frequency is applied to the plurality of electrodes through the second power supply, so that the electrons and positive ions in the plasma flow into different target parts and stay between the plurality of electrodes and on the surfaces of the plurality of target parts nearby.

Therefore, a temperature rise of the substrate and damage to a film formed on the substrate can be suppressed.

Description of drawings

FIG. 1 is a schematic diagram of a plasma device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a vacuum vessel, an electrode, a target member, a gas pipe 1 and a substrate holder taken along line II-II shown in FIG. 1 .

FIG. 3 is an enlarged view of the region REG shown in FIG. 2 .

FIG. 4 is a cross-sectional view of the vacuum container, electrodes, target members, and substrate holder taken along line IV-IV shown in FIG. 1 .

FIG. 5 is a conceptual diagram for explaining the operation of the plasma device shown in FIG. 1 .

FIG. 6 is a conceptual diagram showing another arrangement of electrodes in the plasma device shown in FIG. 1 .

FIG. 7 is a conceptual diagram showing still another arrangement of electrodes in the plasma device shown in FIG. 1 .

FIG. 8 is a conceptual diagram showing still another arrangement of electrodes in the plasma device shown in FIG. 1 .

FIG. 9 is a conceptual diagram showing still another arrangement of electrodes in the plasma device shown in FIG. 1 .

Fig. 10 is a schematic diagram of another plasma device according to the embodiment of the present invention.

Fig. 11 is a plan view and a cross-sectional view of the electrode shown in Fig. 10 .

Detailed ways

Embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same symbols are assigned to the same or corresponding parts in the drawings, and descriptions will not be repeated.

FIG. 1 is a schematic diagram of a plasma device according to an embodiment of the present invention. Referring to FIG. 1 , a plasma device 10 according to an embodiment of the present invention includes a vacuum container 1, electrodes 2, 3, target members 4, 5, capacitors (condensers) 6, 7, 13-15, variable inductors 8, 9, A matching circuit 11 , a high-frequency power supply 12 , a low-frequency power supply 16 , filters 17 and 18 , gas pipes 19 to 21 , and a substrate holder 22 .

The vacuum container 1 has a hollow rectangular parallelepiped shape and is made of stainless steel.

Each of the electrodes 2 and 3 has a rectangular planar shape and is made of metal. Furthermore, the electrodes 2 and 3 are arranged outside the vacuum vessel 1 in a planar manner along the top plate 1A of the vacuum vessel 1 . In this case, the electrode 2 is at a distance from the electrode 3 .

The target members 4, 5 are provided corresponding to the electrodes 2, 3, respectively. Furthermore, each of the target members 4 and 5 is inserted into a through hole provided in the top plate 1A of the vacuum container 1 and fixed to the top plate 1A. Furthermore, the target member 4 is arranged in contact with the surface of the electrode 2 on the substrate 30 side, and the target member 5 is arranged in contact with the surface of the electrode 3 on the substrate 30 side. In addition, each of the target members 4 and 5 is made of a dielectric such as SiO ₂ and Si ₃ N ₄ . Furthermore, the target members 4 and 5 are water-cooled by a water-cooling mechanism (not shown).

Capacitor 6 and variable inductance 8 are connected in series between one end of electrode 2 and matching circuit 11 . Capacitor 7 and variable inductance 9 are connected in series between one end of electrode 3 and matching circuit 11 .

The matching circuit 11 is connected between the high-frequency power supply 12 and the variable inductors 8 and 9 and between the high-frequency power supply 12 and the ground potential GND. Furthermore, the matching circuit 11 is composed of variable capacitors 111 and 112 . Variable capacitor 111 is connected between high frequency power supply 12 and variable inductors 8 , 9 . The variable capacitor 112 is connected between the high-frequency power supply 12 and the ground potential GND.

The high-frequency power supply 12 is connected to the variable capacitors 111 and 112 of the matching circuit 11 . The capacitor 13 is connected between the other end of the electrode 2 and the capacitor 15 . The capacitor 14 is connected between the other end of the electrode 3 and the capacitor 15 . Capacitor 15 is connected between capacitors 13 , 14 and ground potential GND.

The low-frequency power supply 16 is connected to filters 17 , 18 . The filter 17 is connected between the low-frequency power source 16 and the electrode 2 . A filter 18 is connected between the low-frequency power supply 16 and the electrode 3 .

The gas pipes 19 to 21 are arranged in the vacuum vessel 1 . Furthermore, the gas piping 19 is arranged on the outside of one side in the width direction of the electrodes 2 and 3 arranged in a planar shape, and is arranged along the longitudinal direction DR1 of the electrodes 2 and 3 . The gas piping 20 is arranged between the adjacent electrodes 2 and 3 along the longitudinal direction DR1 of the electrodes 2 and 3 . The gas piping 21 is arranged outside the other side in the width direction of the electrodes 2 and 3 arranged in a planar shape along the longitudinal direction DR1 of the electrodes 2 and 3 .

The substrate holder 22 is fixed to the bottom surface 1B of the vacuum container 1 by a support mechanism (not shown). Also, the substrate holder 22 has a built-in heater.

Moreover, in the plasma apparatus 10, the board|substrate 30 is arrange|positioned so that it may oppose the target member 4,5. Furthermore, an exhaust system for exhausting gas in the vacuum container 1 is connected to the vacuum container 1 . This exhaust system is composed of, for example, a structure in which a turbo molecular pump (turbo molecular pump) and a rotary pump (rotary pump) are connected in series, and the turbo molecular pump is connected to the vacuum container 1 side.

Capacitor 6 supplies high-frequency current (frequency: 1 MHz to 13.56 MHz) supplied via variable inductance 8 from one end of electrode 2 to electrode 2 . The capacitor 7 supplies the high-frequency current supplied via the variable inductance 9 from one end of the electrode 3 to the electrode 3 .

The variable inductances 8 and 9 allow the high-frequency current supplied from the high-frequency power source 12 via the matching circuit 11 to flow equally to the electrodes 2 and 3 . In this case, the high-frequency current I1 supplied to the electrode 2 and the high-frequency current I2 supplied to the electrode 3 can be measured, and the variable inductance 8 can be adjusted so that the measured high-frequency currents I1 and I2 become equal. , 9, it is also possible to measure in advance the inductance value when the high-frequency currents I1 and I2 become equal, and set the inductance value for the variable inductors 8 and 9 .

The matching circuit 11 supplies the high-frequency current supplied from the high-frequency power supply 12 to the variable inductors 8 and 9 after suppressing reflected waves.

The high-frequency power supply 12 generates a high-frequency current, and supplies the generated high-frequency current to the matching circuit 11 . The capacitor 13 supplies the high-frequency current flowing through the electrode 2 to the capacitor 15 . The capacitor 14 supplies the high-frequency current flowing through the electrode 3 to the capacitor 15 . The capacitor 15 flows the high-frequency current from the capacitors 13 and 14 to the ground potential GND.

The low-frequency power supply 16 generates an alternating voltage in the range of 50 Hz to 50 kHz, and applies the generated alternating voltage to the electrodes 2 and 3 via the filters 17 and 18 . The alternating voltage is a voltage that alternately changes positive and negative with reference to the ground potential.

The filter 17 removes high-frequency components of the alternating voltage from the low-frequency power supply 16 , and applies the high-frequency-component-removed alternating voltage to the electrode 2 . The filter 18 removes high-frequency components of the alternating voltage from the low-frequency power supply 16 , and applies the high-frequency-component-free alternating voltage to the electrodes 3 .

Each of the gas pipes 19 to 21 supplies, for example, argon gas (Ar gas) into the vacuum vessel 1 from a gas tank.

The substrate holder 22 supports the substrate 30 and heats the substrate 30 to a desired temperature.

2 is a cross-sectional view of the vacuum vessel 1 , electrodes 2 and 3 , target members 4 and 5 , gas pipes 19 to 21 , and substrate holder 22 taken along line II-II shown in FIG. 1 .

Referring to FIG. 2 , the target member 4 is bonded to the electrode 2 , and the target member 5 is bonded to the electrode 3 .

Furthermore, the electrode 2 and the target member 4 are arranged so that the target member 4 and the top plate 1A of the vacuum container 1 form a plane. Furthermore, the electrode 3 and the target member 5 are arranged so that the target member 5 and the top plate 1A of the vacuum vessel 1 form a plane.

Each insulating flange (insulating flange) 25, 26 has a substantially L-shaped cross-sectional shape. Furthermore, the insulating flange 25 is arranged between the electrode 2 and the target member 4 and the top plate 1A of the vacuum container 1 , and the insulating flange 26 is arranged between the electrode 3 and the target member 5 and the top plate 1A of the vacuum container 1 .

The ground frames 23 and 24 are made of, for example, aluminum (aluminum) or stainless steel, and are fixed to the top plate 1A of the vacuum vessel 1 . Furthermore, the ground frame 23 closes one end side of the insulating flange 25 . Also, the ground frame 24 closes one end side of the insulating flange 26 .

The electrodes 2, 3 each have a width W1. Moreover, the distance between the electrode 2 and the electrode 3 is the distance D1. The width W1 is, for example, 50 mm to 200 mm, and the interval D1 is, for example, 100 mm to 200 mm. In addition, the electrodes 2 and 3 have mutually equal areas. Furthermore, the target members 4, 5 have the same area as the electrodes 2, 3, respectively.

The distance between the target members 4 and 5 and the substrate 30 is, for example, 20 mm to 100 mm.

The vacuum container 1 has an exhaust port EXH on the bottom surface 1B. The exhaust system is connected to the exhaust port EXH to discharge the gas in the vacuum container 1 .

The gas pipes 19 to 21 have holes 19A, 20A, and 21A, respectively. Furthermore, the holes 19A, 20A, and 21A are oriented in a direction opposite to the direction from the electrodes 2 and 3 to the substrate 30 . In addition, as shown in FIG. 1 , a plurality of holes 19A, 20A, and 21A are provided in the longitudinal direction DR1 of the electrodes 2 and 3 .

Furthermore, the low-frequency power supply 16 applies an alternating voltage to the electrodes 2 and 3 .

FIG. 3 is an enlarged view of the region REG shown in FIG. 2 . Referring to FIG. 3 , through holes 401 are provided in insulating flange 25 and electrodes 2 , and tapholes 402 are provided in top plate 1A of vacuum container 1 . Also, an insulating collar 403 is inserted into the through hole 401 . The bolt 404 passes through the insulating collar 403 and is screwed into the screw hole 402 . Thus, the bonded electrode 2 and target member 4 are fixed to the top plate 1A of the vacuum container 1 . In addition, an insulating collar 403 is provided to insulate the bolt 404 from the electrode 2 .

Furthermore, on the top plate 1A of the vacuum container 1 , an O-ring 405 is arranged in contact with the insulating flange 25 , and on the electrode 2 , an O-ring 406 is arranged in contact with the insulating flange 25 . Furthermore, the airtightness of the vacuum vessel 1 is maintained by the O-rings 405 and 406 .

One end side of the insulating flange 25 is located in the space 410 . Furthermore, the distance D2 between the one end side of the insulating flange 25 and the top plate 1A of the vacuum container 1A, and the distance D3 between the one end side of the insulating flange 25 and the target member 4 are set to be smaller than 1 mm. In this case, the interval D2 may be the same as or different from the interval D3.

In addition, screw holes 407 are provided in the top plate 1A of the vacuum container 1 , and through holes 408 are provided in the ground frame 23 . Furthermore, a bolt 409 is passed through the through hole 408 and screwed to the screw hole 407 . Thereby, the ground frame 23 is fixed to the top plate 1A of the vacuum container 1 so as not to contact the target member 4 and the insulating flange 25 to close the space 410 . The ground frame 23 is provided to prevent discharge in the space 410 and to prevent the insulating flange 25 from being exposed to the plasma in case plasma is generated in the vacuum container 1 .

In addition, the electrode 2 on the other side, the target member 4 , the ground frame 23 , and the insulating flange 25 shown in FIG. 2 also have the same structure as that shown in FIG. 3 . Furthermore, the electrode 3 and the target member 5 shown in FIG. 2 are also fixed to the top plate 1A of the vacuum vessel 1 by the same method as the electrode 2 and the target member 4 shown in FIG. 3 .

FIG. 4 is a cross-sectional view of the vacuum container 1 , the electrode 3 , the target member 5 and the substrate holder 22 taken along line IV-IV shown in FIG. 1 .

Referring to FIG. 4 , both ends of the target member 5 in the longitudinal direction DR1 are also fixed to the top plate 1A of the vacuum container 1 by the ground frame 24 . Furthermore, both ends of the electrode 3 in the longitudinal direction DR1 are also fixed to the ground frame 24 by insulating flanges 26 so as to be in contact with the target member 5 . In addition, the electrode 3, the target member 5, the ground frame 24, and the insulating flange 26 are constituted by the same structure as that shown in FIG. 3 .

Further, the high-frequency power supply 12 supplies a high-frequency current to the electrode 3 from the one end 3A of the electrode 3 .

The mechanism for fixing the electrode 2 to the top plate 1A of the vacuum container 1 in the longitudinal direction DR1 of the electrodes 2 and 3 is also the same as the mechanism for fixing the electrode 3 to the top plate 1A of the vacuum container 1 shown in FIG. 4 .

The operation of the plasma device 10 will be described. FIG. 5 is a conceptual diagram for explaining the operation of the plasma device 10 shown in FIG. 1 . When forming a film on the substrate 30 by sputtering using the plasma apparatus 10, the inside of the vacuum container 1 is evacuated to 1×10 ⁻³ Pa or less using an exhaust system.

Then, Ar gas is introduced into the vacuum vessel 1 through the gas pipes 19 to 21 . In this case, the flow rate of the Ar gas is, for example, 50 sccm to 200 sccm. Furthermore, Ar gas is supplied into the vacuum vessel 1 from the holes 19A, 20A, and 21A of the gas pipes 19 to 21 toward the top plate 1A of the vacuum vessel 1 . And the pressure in the vacuum container 1 is set to the range of 0.13Pa-133.3Pa using an exhaust system.

After that, the high-frequency power supply 12 generates, for example, 5 kW of high-frequency power, and supplies the generated high-frequency power of 5 kW to one end of the electrodes 2 and 3 via the matching circuit 11, the variable inductors 8 and 9, and the capacitors 6 and 7. .

Furthermore, the low-frequency power supply 16 applies low-frequency power of 5 kW to the electrodes 2 and 3 via the filters 17 and 18 . Thus, an alternating voltage is applied to the electrodes 2 , 3 .

As a result, high-frequency currents having the same current value flow through the electrodes 2 and 3 along the longitudinal direction DR1. Then, an induced electric field is generated around the target members 4 and 5 by the high-frequency current flowing in the longitudinal direction DR1 through the electrodes 2 and 3 , thereby generating plasma 40 of Ar gas introduced into the vacuum vessel 1 .

Also, when a positive bias is applied to the electrode 2 by an alternating voltage, electrons in the plasma 40 flow into the target member 4 and positive ions in the plasma 40 flow into the target member 5 . Also, when a negative bias is applied to the electrode 2 by an alternating voltage, positive ions in the plasma 40 flow into the target member 4 and electrons in the plasma 40 flow into the target member 5 .

As a result, charged particles (electrons and positive ions) in the plasma 40 stay in the region spanning between the electrodes 2 , 3 and flow into the target members 4 , 5 . Then, the target members 4 and 5 are sputtered by the inflow of positive ions, and a film having substantially the same composition as the constituent elements of the target members 4 and 5 is deposited on the substrate 30 .

When the film is deposited on the substrate 30, the high-frequency power supply 12 stops the supply of high-frequency power, and the low-frequency power supply 16 stops the supply of low-frequency power. Then, the supply of Ar gas into the vacuum container 1 was stopped, and the inside of the vacuum container 1 was evacuated to 1×10 ⁻³ Pa or less by the exhaust system. Thereby, the operation of forming a film by sputtering is completed.

As described above, in the plasma device 10 , a high-frequency current flows into the flat plate electrodes 2 and 3 along the longitudinal direction DR1 from one end. As a result, an induced electric field is generated near the surface of the target members 4 and 5 by the high-frequency current flowing through the electrodes 2 and 3, and an inductance of the Ar gas introduced into the vacuum vessel 1 is generated near the surface of the target members 4 and 5. Coupled plasma40. Moreover, since an alternating voltage is applied to the electrodes 2, 3 by a low-frequency power supply, electrons in the plasma 40 alternately flow into the target member 4 and the target member 5, and positive ions in the plasma 40 alternately flow into the target member 5 and the target member 5. The target member 4 and charged particles (electrons and positive ions) in the plasma 40 stay in the vicinity of the target members 4 and 5 .

Therefore, the inflow of the charged particles in the plasma 40 to the substrate 30 is suppressed, and the temperature rise of the film and the damage to the film during film formation can be suppressed.

Furthermore, in the plasma device 10, since plasma is generated by inductive coupling, high-density plasma can be generated in the vicinity of the target members 4 and 5 without using a magnetic field.

Moreover, since the plasma apparatus 10 does not use a magnetic field, distribution of the plasma 40 does not become uneven, and target members 4 and 5 are uniformly consumed by sputtering. Therefore, the utilization efficiency of the target members 4 and 5 can be improved.

In addition, since the plasma device 10 uses plasma generated by inductive coupling, the decomposition efficiency of the gaseous substance is high, and the elements of the target members 4 and 5 can efficiently react with the decomposed gaseous substance.

In addition, since the plasma device 10 uses plasma generated by inductive coupling, high-density plasma can be generated even at low gas pressure, and a film can be grown in an environment with a high degree of vacuum. As a result, impurities in the formed film can be reduced.

In addition, in the plasma device 10, since the Ar gas is ejected from the gas pipes 19 to 21 toward the top plate 1A of the vacuum container 1, the direct influence of the Ar gas on the substrate 30 can be avoided, and the Ar gas can be dispersed throughout the vacuum container. within 1.

FIG. 6 is a conceptual diagram showing another arrangement of electrodes in the plasma device 10 shown in FIG. 1 . 6, in the plasma device 10, the electrodes 2 and 3 can also be replaced by electrodes 31-33, the target components 4 and 5 can be replaced by target components 34-36, and the variable inductors 8 and 9 can be replaced by Variable inductance 51-53. In this case, the plasma device 10 further includes inductors 41 to 43 .

The electrodes 31 to 33 each have the same rectangular planar shape as the electrodes 2 and 3 and are made of aluminum. The electrodes 31 to 33 are arranged in contact with the target members 34 to 36 by the same method as the electrodes 2 and 3 . Furthermore, the electrodes 31 to 33 are arranged in a planar shape at the interval D1. In addition, when the areas of the electrodes 31 to 33 are respectively defined as S ₃₁ to S ₃₃ , the relationship of S ₃₁ +S ₃₃ =S ₃₂ is established.

The target members 34-36 are provided corresponding to the electrodes 31-33, respectively. The target members 34 to 36 are planarly fixed to the top plate 1A of the vacuum container 1 by the same method as the target members 4 and 5 . Furthermore, the target members 34 to 36 each have the same area as the electrodes 31 to 33 and are arranged in contact with the surfaces of the electrodes 31 to 33 on the substrate 30 side.

Filter 17 removes high-frequency components of the alternating voltage received from low-frequency power supply 16 , and applies the alternating voltage from which high-frequency components have been removed to electrodes 31 and 33 via inductors 41 and 42 .

Furthermore, the filter 18 removes the high-frequency component of the alternating voltage received from the low-frequency power supply 16 , and applies the alternating voltage from which the high-frequency component has been removed to the electrode 32 via the inductor 43 .

When using three electrodes 31-33, the low-frequency power supply 16 applies an alternating voltage to electrodes 31-33 so that electrodes 31, 33 may become the same polarity, and electrode 32 may become the opposite polarity to electrodes 31, 33.

When electrodes 31 to 33 are used, high frequency power supply 12 supplies high frequency current to electrodes 31 to 33 from one end 31A, 32A, 33A in the longitudinal direction of electrodes 31 , 32 , 33 . In this case, assuming that the high-frequency currents flowing to the electrodes 31 to 33 are respectively I ₃₁ to I ₃₃ , the variable inductors 51 to 53 are adjusted so that the relationship of I ₃₁ +I ₃₃ =I ₃₂ holds. High-frequency currents I 31 to I 33 flowing to the electrodes ₃₁ to ₃₃ . Furthermore, when the high-frequency currents I _{31 to I 33 flowing to the electrodes 31 to 33 are adjusted so that the relationship of I 31} +I ₃₃ =I ₃₂ is established, the high-frequency currents I ₃₁ to I ₃₃ supplied to the electrodes 31 to 33 can be measured. For the currents I ₃₁ to I ₃₃ , the variable inductances 51 to 53 are adjusted so that the relationship of _{I 31 +} I ₃₃ =I ₃₂ is established among the measured high-frequency currents I 31 to I ₃₃ , and they may be measured in advance. The inductance value when the relationship of I ₃₁ +I ₃₃ =I ₃₂ holds, and the measured inductance value is set for the variable inductors 51 to 53 .

When a positive bias is applied to the electrodes 31 , 33 , electrons in the plasma 40 flow into the target members 34 , 36 , and positive ions in the plasma 40 flow into the target member 35 . Furthermore, when a negative bias is applied to the electrodes 31 , 33 , electrons in the plasma 40 flow into the target member 35 , and positive ions in the plasma 40 flow into the target members 34 , 36 . Furthermore, between the areas S ₃₁ to S ₃₃ of the electrodes 31 to 33 , the relationship of S ₃₁ +S ₃₃ =S ₃₂ holds as described above. As a result, the area of the target member into which electrons flow is equal to the area of the target member into which positive ions flow, and the plasma 40 is stabilized.

Therefore, even when the plasma device 10 includes three electrodes 31 to 33, as described above, charged particles (electrons and positive ions) in the plasma 40 remain between adjacent electrodes (=electrodes 31, 32 between the electrodes 32 and 33) and the vicinity of the surface of the target members 34-36. As a result, the inflow of charged particles in the plasma 40 to the substrate 30 is suppressed, so that a rise in the temperature of the film and damage to the film during film formation can be suppressed.

In addition, in FIG. 6 , capacitors corresponding to capacitors 6 and 7 are omitted.

FIG. 7 is a conceptual diagram showing still another electrode arrangement in the plasma device 10 shown in FIG. 1 . 7, in the plasma device 10, the electrodes 2, 3 can also be replaced by electrodes 61 ~ 6n (n is an odd number of 3 or more), and the target components 4, 5 can be replaced by target components 71 ~ 7n, variable The inductors 8 and 9 are replaced by variable inductors 91-9n. In this case, the plasma device 10 further includes inductors 81 to 8n.

Each of the electrodes 61 to 6n has the same rectangular planar shape as the electrodes 2 and 3, and is made of aluminum. The electrodes 61 to 6n are arranged in contact with the target members 71 to 7n, respectively, by the same method as the electrodes 2 and 3 . And the electrodes 61-6n are arrange|positioned in planar shape with the said space|interval D1. In addition, when the areas of the electrodes 61 to 6n are respectively defined as S ₆₁ to S _6n , S ₆₁ +S ₆₃ =S ₆₂ , S ₆₃ +S ₆₅ =S ₆₄ , ..., S _6n−2 +S _6n =S _{6n− 1} relationship is established.

The target members 71 to 7n are provided corresponding to the electrodes 61 to 6n, respectively. The target members 71 to 7n are planarly fixed to the top plate 1A of the vacuum container 1 by the same method as the target members 4 and 5 . Furthermore, the target members 71 to 7n each have the same area as the electrodes 61 to 6n, and are arranged in contact with the surfaces of the electrodes 61 to 6n on the substrate 30 side.

The filter 17 removes the high-frequency components of the alternating voltage received from the low-frequency power supply 16, and applies the alternating voltage from which the high-frequency components have been removed to the electrodes 61, 63, 8n via inductors 81, 83, 85, ..., 8n. 65, ..., 6n.

Furthermore, the filter 18 removes the high-frequency component of the alternating voltage received from the low-frequency power supply 16, and applies the high-frequency component-removed alternating voltage to the electrodes 62, 8n-1 through the inductors 82, 84, ..., 8n-1. 64, ..., 6n-1.

In the case of using n electrodes 61 to 6n, the low-frequency power supply 16 is such that the electrodes 61, 63, ..., 6n have the same polarity and the electrodes 62, 64, ..., 6n-1 have the same polarity as the electrodes 61, 63, ..., 6n. Alternating voltages are applied to the electrodes 61 to 6n in a manner of opposite polarity.

When the electrodes 61 to 6n are used, the high frequency power supply 12 supplies a high frequency current to the electrodes 61 to 6n from one end 61A to 6nA in the longitudinal direction of the electrodes 61 to 6n. In this case, assuming that the high-frequency currents flowing to the electrodes 61 to 6n are respectively I ₆₁ to I _6n , the inductances 91 to 9n are variable so that I ₆₁ +I ₆₃ =I ₆₂ , I ₆₃ +I ₆₅ The high-frequency currents I 61 to I 6n flowing to the electrodes 61 to _6n are adjusted so that the relationship of =I ₆₄ , . . . , I _6n−2 +I _6n =I _{6n −1} holds. Then, the flow to the electrodes 61 to 6n is adjusted so that the relationship of I ₆₁ +I ₆₃ =I ₆₂ , I ₆₃ +I ₆₅ =I ₆₄ , ..., I _6n-2 +I _6n =I _6n-1 is established. In the case of the high-frequency currents I ₆₁ to I _6n , the high- _frequency currents I ₆₁ to I _6n supplied to the electrodes 61 to 6n can be measured so that I ₆₁ can be set between the measured high-frequency currents I ₆₁ to I 6n +I ₆₃ =I ₆₂ , I ₆₃ +I ₆₅ =I ₆₄ , ..., I _6n-2 +I _6n =I _6n-1 to adjust the variable inductance 91~9n, or measure I ₆₁ in advance The inductance value when the relationship of +I ₆₃ =I ₆₂ , I ₆₃ +I ₆₅ =I ₆₄ , ..., I _6n-2 +I _6n =I _6n-1 is established, and this measurement is set for the variable inductors 91 to 9n out the inductance value.

When a positive bias is applied to the electrodes 61, 63, ..., 6n, electrons in the plasma 40 flow into the target parts 71, 73, ..., 7n, and positive ions in the plasma 40 flow into the target parts 72, 74, ..., 7n -1. Furthermore, when a negative bias is applied to the electrodes 61, 63, . . . , 6n, positive ions in the plasma 40 flow into the target members 71, 73, . , 7n-1. In addition, between the areas S ₆₁ to S _6n of the electrodes 61 to 6n, as described above, S ₆₁ +S ₆₃ =S ₆₂ , S ₆₃ +S ₆₅ =S ₆₄ , ..., S _6n−2 +S _6n = The relationship of S _6n-1 is established. As a result, the area of the target member into which electrons flow is equal to the area of the target member into which positive ions flow, and the plasma 40 is stabilized.

Therefore, even when the plasma device 10 includes three or more odd-numbered electrodes 61 to 6n, as described above, charged particles (electrons and positive ions) in the plasma 40 stay between adjacent electrodes (=electrode 61, 62, between electrodes 62, 63, ..., electrodes 6n-1, 6n) and the surface vicinity of the target members 71-7n. As a result, the inflow of charged particles in the plasma 40 to the substrate 30 is suppressed, so that a rise in the temperature of the film and damage to the film during film formation can be suppressed.

In addition, in FIG. 6 , capacitors corresponding to capacitors 6 and 7 are omitted.

FIG. 8 is a conceptual diagram showing still another electrode arrangement in the plasma device 10 shown in FIG. 1 . 8, in the plasma device 10, the electrodes 2 and 3 can also be replaced by electrodes 101-104, the target components 4 and 5 can be replaced by target components 105-108, and the variable inductors 8 and 9 can be replaced by Variable inductance 121~124. In this case, the plasma device 10 further includes inductors 113-116.

The electrodes 101 to 104 each have the same rectangular planar shape as the electrodes 2 and 3 and are made of aluminum. The electrodes 101 to 104 are arranged in contact with the target members 105 to 108 respectively by the same method as the electrodes 2 and 3 . Furthermore, the electrodes 101 to 104 are arranged in a planar shape at the interval D1. In addition, the electrodes 101 to 104 have mutually equal areas.

The target members 105 to 108 are provided corresponding to the electrodes 101 to 104, respectively. The target members 105 to 108 are planarly fixed to the top plate 1A of the vacuum container 1 by the same method as the target members 4 and 5 . Furthermore, the target members 105 to 108 each have the same area as the electrodes 101 to 104 and are arranged in contact with the surfaces of the electrodes 101 to 104 on the substrate 30 side.

Filter 17 removes high frequency components of the alternating voltage received from low frequency power supply 16 , and applies the high frequency component removed alternating voltage to electrodes 105 , 107 via inductors 113 , 114 .

And the filter 18 removes the high frequency component of the alternating voltage received from the low frequency power supply 16, and applies the high frequency component removed alternating voltage to the electrodes 106 and 108 via the inductors 115 and 116.

When four electrodes 101 to 104 are used, the low-frequency power supply 16 applies alternating current to the electrodes 101 to 104 so that the electrodes 101 and 103 have the same polarity and the electrodes 102 and 104 have the opposite polarity to the electrodes 101 and 103 . Voltage.

When electrodes 101-104 are used, high-frequency power supply 12 supplies high-frequency current to electrodes 101-104 from one end 101A, 102A, 103A, 104A in the longitudinal direction of electrodes 101, 102, 103, 104. In this case, the variable inductances 121 to 124 adjust the high frequency currents flowing to the electrodes 101 to 104 so that the high frequency currents flowing to the electrodes 101 to 104 become equal to each other. Furthermore, when the high-frequency currents flowing to the electrodes 101-104 are adjusted so that the high-frequency currents flowing to the electrodes 101-104 become equal to each other, the high-frequency currents supplied to the electrodes 101-104 can be measured, The variable inductors 121 to 124 are adjusted so that the measured high frequency currents become equal to each other, and the inductance values when the high frequency currents flowing to the electrodes 101 to 104 are equal to each other may be measured in advance, and the variable inductors 121 ~124 to set the measured inductance value.

When a positive bias is applied to the electrodes 101 , 103 , electrons in the plasma 40 flow into the target members 105 , 107 , and positive ions in the plasma 40 flow into the target members 106 , 108 . Furthermore, when a negative bias is applied to the electrodes 101 and 103 , electrons in the plasma 40 flow into the target members 106 and 108 , and positive ions in the plasma 40 flow into the target members 105 and 107 . Furthermore, as described above, the areas of the electrodes 101 to 104 are equal to each other. As a result, the area of the target member into which electrons flow is equal to the area of the target member into which positive ions flow, and the plasma 40 is stabilized.

Therefore, even when the plasma device 10 includes four electrodes 101 to 104, as described above, charged particles (electrons and positive ions) in the plasma 40 remain between adjacent electrodes (=electrodes 101, 102 between the electrodes 102 and 103, and between the electrodes 103 and 104) and the surface vicinity of the target members 105-108. As a result, the inflow of charged particles in the plasma 40 to the substrate 30 is suppressed, so that a rise in the temperature of the film and damage to the film during film formation can be suppressed.

FIG. 9 is a conceptual diagram showing still another arrangement of electrodes in the plasma device 10 shown in FIG. 1 . 9, in the plasma device 10, the electrodes 2 and 3 can also be replaced by electrodes 131-13m (m is an even number greater than 4), and the target components 4 and 5 can be replaced by target components 141-14m. The inductors 8 and 9 are replaced with variable inductors 151-15m. In this case, the plasma device 10 further includes inductors 161 to 16m.

Each of the electrodes 131 to 13m has the same rectangular planar shape as the electrodes 2 and 3, and is made of aluminum. The electrodes 131 to 13m are arranged in contact with the target members 141 to 14m, respectively, by the same method as the electrodes 2 and 3 . Furthermore, the electrodes 131 to 13m are arranged in a planar shape at the interval D1. In addition, the areas of the electrodes 131 to 13m are equal to each other.

The target members 141 to 14m are provided corresponding to the electrodes 131 to 13m, respectively. The target members 141 to 14m are fixed to the top plate 1A of the vacuum container 1 in a planar shape by the same method as the target members 4 and 5 . Furthermore, the target members 141 to 143m each have the same area as the electrodes 131 to 13m, and are arranged in contact with the surfaces of the electrodes 131 to 13m on the substrate 30 side.

The filter 17 removes the high-frequency component of the alternating voltage received from the low-frequency power supply 16, and applies the alternating voltage from which the high-frequency component has been removed to the electrodes 131, 133, ..., 13m-1.

Furthermore, the filter 18 removes the high-frequency component of the alternating voltage received from the low-frequency power supply 16, and applies the alternating voltage from which the high-frequency component has been removed to the electrodes 132, 134, ..., 13m.

In the case of using m electrodes 131 to 13m, the low-frequency power supply 16 is such that the electrodes 131, 133, ..., 13m-1 have the same polarity and the electrodes 132, 134, ..., 13m have the same polarity as the electrodes 131, 133, ..., Alternating voltages are applied to the electrodes 131 to 13m in such a manner that the polarities of 13m-1 are reversed.

When the electrodes 131 to 13m are used, the high frequency power supply 12 supplies a high frequency current to the electrodes 131 to 13m from one end 131A to 13mA in the longitudinal direction of the electrodes 131 to 13m. In this case, the high-frequency currents flowing to the electrodes 131-13m are adjusted so that the high-frequency currents flowing to the electrodes 131-13m become equal to each other. Furthermore, when the high-frequency currents flowing to the electrodes 131-13m are adjusted so that the high-frequency currents flowing to the electrodes 131-13m become equal to each other, the high-frequency currents supplied to the electrodes 131-13m can be measured, The variable inductances 151-15m are adjusted so that the measured high-frequency currents become equal to each other, and the inductance values when the high-frequency currents flowing to the electrodes 131-13m become equal to each other can be measured in advance, and the variable inductances can be adjusted. Inductance 151 to 15m sets the measured inductance value.

When a positive bias is applied to the electrodes 131, 133..., 13m-1, electrons in the plasma 40 flow into the target parts 141, 143,..., 14m-1, and positive ions in the plasma 40 flow into the target parts 142, 144, ..., 14m. Furthermore, when a negative bias is applied to the electrodes 131, 133, . . . , 13m-1, positive ions in the plasma 40 flow into the target members 141, 143, . , 144, ..., 14m. In addition, as described above, the areas of the electrodes 131 to 13m are equal to each other. As a result, the area of the target member into which electrons flow is equal to the area of the target member into which positive ions flow, and the plasma 40 is stabilized.

Therefore, when the plasma device 10 includes four or more even-numbered electrodes 131 to 13m, as described above, charged particles (electrons and positive ions) in the plasma 40 remain between adjacent electrodes (= Between the electrodes 131 and 132, between the electrodes 132 and 133, . As a result, the inflow of charged particles in the plasma 40 to the substrate 30 is suppressed, so that a rise in the temperature of the film and damage to the film during film formation can be suppressed.

As described above, when the plasma device 10 includes two or more electrodes whose planar shape is rectangular, a high-frequency current is made to flow into the two or more electrodes from one end in the longitudinal direction, and near the surface of the target member is Inductive coupling generates plasma 40 . Furthermore, charged particles (electrons and positive ions) in the plasma 40 remain between the electrodes and in the vicinity of the surface of the target member.

Therefore, when there are two or more electrodes, the inflow of charged particles to the substrate 30 is suppressed, and the temperature rise and damage to the film during film formation can be suppressed.

Furthermore, by using the various electrodes 2, 3, electrodes 31 to 33, electrodes 61 to 6n, electrodes 101 to 104, and electrodes 131 to 13m, it is possible to suppress a rise in the temperature of the film and damage to the film during film formation. A film is formed on a substrate 30 of any size.

Fig. 10 is a schematic diagram of another plasma device according to the embodiment of the present invention. The plasma device according to the embodiment of the present invention may be a plasma device 10A shown in FIG. 10 .

Referring to FIG. 10 , plasma device 10A is the same as plasma device 10 except that electrodes 2 and 3 of plasma device 10 shown in FIG. 1 are replaced with electrodes 201 and 301 , respectively.

The electrodes 201, 301 are arranged in contact with the target members 4, 5 by the same method as the electrodes 2, 3, respectively. Furthermore, the electrodes 201 and 301 have the same area as each other.

FIG. 11 is a plan view and a cross-sectional view of the electrode 201 shown in FIG. 10 . In addition, FIG. 11( a ) is a plan view, and FIG. 11( b ) is a cross-sectional view.

Referring to FIG. 11 , the electrode 201 includes a plate member 2010 and capacitive elements 2020 - 2023 . The plate member 2010 has a rectangular planar shape and is made of metal. The capacitive elements 2020 to 2023 are arranged in the longitudinal direction DR1 of the electrode 201 at a constant interval D4. The interval D4 is determined according to the length of the electrodes 201 and is, for example, 150 to 300 mm. Furthermore, each of capacitive elements 2020 to 2023 is provided on surface 2010A of plate member 2010 on the substrate 30 side over the entire width W1 of plate member 2010 . Furthermore, each of the capacitive elements 2020 to 2023 has a width W2 in the longitudinal direction DR1 of the electrode 201 . The width W2 is, for example, 10 to 40 mm.

Capacitance element 2020 includes through hole 2011 , metal plates 2012 , 2013 , capacitors 2014 , 2015 , and insulator 2016 . The through hole 2011 runs through the plate member 2010 and has a width W2.

Each of the metal plates 2012 and 2013 has a substantially L-shaped cross-sectional shape. One end of the metal plate 2012 is electrically connected to the plate member 2010 on one side of the through hole 2011 . One end of the metal plate 2013 is electrically connected to the plate member 2010 on the other side of the through hole 2011 .

Capacitors 2014 and 2015 are connected in parallel between metal plate 2012 and metal plate 2013 .

Insulator 2016 is filled in through hole 2011 so as to cover part of metal plates 2012 and 2013 and capacitors 2014 and 2015 .

Each of the capacitive elements 2021 to 2023 has the same configuration as that of the capacitive element 2020 .

As described above, the electrode 201 is constituted by an inductor and a capacitor (capacitance) electrically connected in series in the longitudinal direction DR1 . Accordingly, the impedance (impedance) in the longitudinal direction DR1 of the electrode 201 is reduced. Furthermore, the impedance of the electrode 201 becomes the minimum when the resonance condition is satisfied, and the potential difference between both ends of the electrode 201 is constituted only by the potential difference due to the resistance component.

Therefore, even if the distance in the longitudinal direction DR1 of the electrode 201 becomes longer, plasma with a small potential difference can be generated.

In addition, the electrode 301 shown in FIG. 10 has the same configuration as the electrode 201 shown in FIG. 11 .

Furthermore, the operation of forming a film on the substrate 30 by sputtering in the plasma apparatus 10A is the same as the operation of forming a film on the substrate 30 by sputtering in the plasma apparatus 10 .

As described above, the plasma device 10A includes the electrodes 201 and 301 in which the plurality of capacitive elements 2020 to 2023 arranged along the longitudinal direction DR1 are arranged at a constant interval D2, so the impedance in the longitudinal direction DR1 of the electrodes 201 and 301 is reduced. , more high-frequency current flows along the long-side direction DR1 of the electrodes 201 and 301 .

Therefore, in the plasma device 10A, in addition to the effect of the plasma device 10, the density of the plasma 40 generated by inductive coupling can also be increased. Furthermore, in the plasma device 10A, even if the lengths of the electrodes 201 and 301 are increased, plasma with a small potential difference can be generated.

In addition, in the plasma device 10A, the plurality of capacitive elements 2020 to 2023 may not be arranged at a constant interval D2 in the longitudinal direction DR1 of the electrodes 201 and 301 . This is because if the capacitive elements 2020 to 2023 are arranged so as to be perpendicular to the direction of the high-frequency current, the impedance in the longitudinal direction DR1 of the electrodes 201 and 301 decreases compared to the case where the capacitive elements 2020 to 2023 are not arranged. The density of the plasma 40 can be increased, and plasma with a small potential difference can be generated.

Furthermore, in the plasma device 10A, the same changes as in the case of replacing the electrodes 2 and 3 with the electrodes 31 to 33, the electrodes 61 to 6n, the electrodes 101 to 104, and the electrodes 131 to 13m in the plasma device 10 can also be performed. . Therefore, also in the plasma apparatus 10A, it is possible to form a film on the substrate 30 of any size while suppressing a rise in film temperature and damage to the film during film formation.

In the description above, the case of using Ar gas as the gas for sputtering has been described, but in the embodiments of the present invention, it is not limited thereto, and a mixed gas of Ar gas and oxygen or nitrogen may also be used as the gas for sputtering. with gas.

In addition, in the above description, it has been described that each of the plasma devices 10 and 10A is disposed along the longitudinal direction DR1 of the electrodes 2 and 3 and has a direction from the substrate 30 to the target member (the target member 4 , 5 , etc.) In the case of the gas pipes 19 to 21 of the holes 19A, 20A, and 21A, but in the embodiment of the present invention, it is not limited thereto. The plasma device in the embodiment of the present invention includes introducing Ar gas into the vacuum vessel 1. gas piping.

Moreover, the plasma device according to the embodiment of the present invention only needs to include the following parts: a plurality of electrodes arranged in a planar shape and each having a rectangular planar shape; a plurality of target members arranged corresponding to the plurality of electrodes, each composed of a dielectric constituted and arranged in contact with the surface of the substrate side of the corresponding electrode; the first power supply causes a high-frequency current having a first frequency to flow into the plurality of electrodes from one end of the plurality of electrodes; The voltage having the second frequency is applied to the plurality of electrodes in such a manner that the voltage of the second frequency with a lower frequency is alternately applied to the two electrodes.

When the plasma apparatus according to the embodiment of the present invention includes a plurality of electrodes, a plurality of target members, and first and second power sources, by using the first power source to flow a high-frequency current into the plurality of electrodes, plasma can be generated by inductive coupling, And by using the second power supply to alternately apply the voltage with the second frequency to the plurality of electrodes, electrons and positive ions in the plasma flow into different target parts. As a result, electrons and positive ions in the plasma stay between the plurality of electrodes and in the vicinity of the surfaces of the plurality of target members, whereby a film can be formed on the substrate 30 while suppressing a rise in film temperature and damage to the film during film formation.

It should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is shown not by the description of the above-described embodiments but by the claims, and it is intended that all changes within the meaning and range equivalent to the claims are included.

Industrial availability

The present invention is applied to plasma devices.

Claims (7)

1. A plasma device comprising: a plurality of electrodes arranged in a planar shape and each having a rectangular planar shape; a plurality of target members provided corresponding to the plurality of electrodes, each of the plurality of target members is composed of a dielectric and arranged in contact with the surface of the corresponding electrode on the substrate side; a first power source that flows high-frequency current having a first frequency into the plurality of electrodes from one end of the plurality of electrodes; and The second power supply applies a voltage having the second frequency to the plurality of electrodes so as to alternately apply a voltage having the second frequency lower than the first frequency to the two electrodes. 2. The plasma device of claim 1, wherein each of the plurality of electrodes comprises: a plate member having said planar shape and consisting of metal; A plurality of capacitive elements are inserted into a plurality of through holes formed in the surface of the flat member on the substrate side in the longitudinal direction of the flat member, and both ends of the plurality of capacitive elements are connected to The flat parts are electrically connected; and A plurality of insulators covering the plurality of capacitive elements. 3. The plasma apparatus according to claim 2, wherein each of the plurality of capacitive elements is constituted by a plurality of capacitors connected in parallel in the flat plate member. 4. The plasma device according to claim 2 or 3, wherein the plurality of through holes are formed in the flat plate member at set intervals. 5. The plasma device according to any one of claims 1 to 4, further comprising a plurality of inductors arranged between the first power supply and the plurality of electrodes, the plurality of The inductance sets the plurality of high-frequency currents flowing into the plurality of electrodes to be equal. 6. The plasma device according to any one of claims 1 to 5, further comprising a plurality of gas pipes extending between two adjacent electrodes and outside the plurality of electrodes. The electrodes are arranged in the longitudinal direction. 7. The plasma apparatus according to claim 6, wherein each of the plurality of gas pipes has a plurality of holes facing in a direction opposite to a direction from the electrode to the substrate.

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