JP2001085414A - Device and method for plasma treatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma treatment device and a plasma treatment method by which uniform plasma treatment can be performed with high efficiency. SOLUTION: A plasma treating device performs plasma treatment on a substrate to be treated between an upper electrode and a lower electrode which are faced oppositely to each other under a short inter-electrode distance under a high discharge pressure condition, many nozzles 9 are radially arranged around the discharge space sandwiched between the upper and lower electrodes with their openings being directed toward the discharge space. The nozzles 9 are connected to a gas supplying device 11 through a first valve VA and a vacuum pump 13 for exhaust through a second valve VB and the flowing direction of gas in the discharge space is changed by switching the blowing-out directions of the gas from the nozzles 9, and the sucking direction of the gas as time elapses by controlling the opening/closing of the valves VA and VB. Therefore, a gas for generating plasma can be supplied uniformly, even under a short inter-electrode distance and high pressure plasma treatment condition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus and a plasma processing method for performing a surface treatment of a workpiece such as a substrate by using plasma.

[0002]

2. Description of the Related Art Plasma etching is known as a method of processing a silicon substrate used for a semiconductor device or the like. In this method, a silicon substrate as an object to be processed is placed in a depressurized processing chamber, a gas for plasma generation is supplied, and a high-frequency voltage is applied between electrodes arranged in the processing chamber to generate plasma. The etching action of generated ions and electrons is used for processing. In recent years, in this plasma etching, for the purpose of improving the etching efficiency and the like, the plasma processing conditions are set to a narrow inter-electrode distance and a high discharge pressure, that is, the distance between the electrodes for generating the plasma discharge to about 5 mm, Plasma processing is performed with the pressure set to about 1/50 atm. By employing such plasma processing conditions, there are many advantages such as a high etching rate and a simplified vacuum evacuation system.

[0003]

However, under the above-mentioned pressure conditions, the behavior of the gas is greatly affected by the collision between the molecules, so that the flow of the plasma generating gas such as oxygen or fluorine-based gas is a viscous flow. Thus, gas supply by free diffusion of gas molecules as in a high vacuum condition is difficult to realize. Therefore, when the above-mentioned narrow electrode / high pressure plasma processing conditions are applied, simply supplying a gas into the processing chamber as in the related art requires only a plasma on the surface of the processing target, particularly the central portion of the processing target surface. There is a drawback that the generated gas does not reach sufficiently.

In order to solve this problem, it is conceivable to forcibly supply a plasma generating gas into the discharge space between the electrodes. However, in this method, a sufficient gas is supplied near the inlet on the gas supply side. However, since an insufficient amount of the plasma generating gas is supplied to the opposite side of the discharge space, a problem that the etching rate is not uniform occurs. As described above, in the conventional plasma processing apparatus,
When the plasma processing conditions of a narrow interelectrode distance and a high discharge pressure are applied to improve the efficiency, there is a problem that it is difficult to perform a uniform plasma processing due to a poor supply of a plasma generating gas.

Accordingly, an object of the present invention is to provide a plasma processing apparatus and a plasma processing method capable of performing uniform plasma processing with high processing efficiency.

[0006]

According to a first aspect of the present invention, there is provided a plasma processing apparatus, wherein a work is arranged on at least one of two electrodes arranged to face each other, and a high-frequency voltage is applied between the two electrodes. A plasma processing apparatus for performing a surface treatment of a workpiece by generating plasma in a space interposed between the two electrodes by performing plasma generation gas from one side of the space interposed between the two electrodes. Gas introducing means for supplying the plasma generating gas in the space and exhausting the gas for plasma generation in the space from the other side of the space with respect to the one side, and changing the supply position and the exhaust position of the gas for plasma generation by the gas introducing means Changing means for changing the direction in which the plasma generating gas flows in the space.

According to a second aspect of the present invention, there is provided the plasma processing apparatus according to the first aspect, wherein the gas introducing means is arranged on a side of the space and has an opening facing the inside of the space. Provided with a plurality of nozzles.

According to a third aspect of the present invention, in the plasma processing apparatus according to the second aspect, each of the plurality of nozzles includes a first valve and a second valve,
Each of the nozzles is connected to a gas supply unit for supplying the plasma generation gas via a first valve, and connected to a gas exhaust unit for exhausting the plasma generation gas via a second valve.

A plasma processing apparatus according to a fourth aspect of the present invention is the plasma processing apparatus according to the second aspect, wherein the changing means includes at least one nozzle for supplying a plasma generating gas among the plurality of nozzles and this nozzle. The combination with at least one nozzle that exhausts the plasma generating gas at a position sandwiching the space is switched over time.

According to a fifth aspect of the present invention, there is provided the plasma processing apparatus according to the third aspect, wherein the changing means is configured to switch the first valve when the first valve of the at least one nozzle is open. The second valve of at least one nozzle with the valve closed is opened, and the combination of the nozzle with the first valve open and the nozzle with the second valve open is changed over time. Switch.

According to a sixth aspect of the present invention, there is provided the plasma processing apparatus according to the first aspect, wherein the gas introducing means is dedicated to a gas supply arranged with an injection port facing the inside of the space. The air conditioner includes a plurality of air supply nozzles and a plurality of exhaust nozzles dedicated to exhaust arranged so that the suction ports face the inside of the space.

According to a seventh aspect of the present invention, in the plasma processing apparatus according to the sixth aspect, the changing means includes at least one of the plurality of air supply nozzles and the plurality of air exhaust nozzles. The combination of at least one exhaust nozzle disposed at a position sandwiching the space with respect to this air supply nozzle among the nozzles is switched over time.

[0013] In the plasma processing method according to the present invention, a work may be arranged on at least one of two electrodes arranged to face each other, and a high-frequency voltage may be applied between the two electrodes so that the two electrodes are applied. A plasma processing method for performing a surface treatment of a workpiece by generating plasma in a space sandwiched between electrodes, wherein a plasma generating gas is supplied from one side to the space sandwiched between the two electrodes, and The gas for plasma generation in the space is exhausted from the other side of the space with respect to the one side, so that the gas for plasma generation flows from the one side to the other side in the space, and the gas for plasma generation in this space Is changed over time.

According to a ninth aspect of the present invention, there is provided the plasma processing method according to the eighth aspect, wherein the introduction of the plasma generating gas is arranged at a side of the space and an opening is formed inside the space. This is done by a plurality of nozzles arranged facing.

A plasma processing method according to a tenth aspect is the plasma processing method according to the ninth aspect, wherein the plurality of nozzles supply a plasma generating gas by a gas supply unit connected via a first valve. The gas is supplied, and the gas for plasma generation is exhausted by gas exhaust means connected via a second valve.

A plasma processing method according to an eleventh aspect is the plasma processing method according to the ninth aspect, wherein at least one of the plurality of nozzles supplies a plasma generating gas.
By switching the combination of one nozzle and at least one nozzle that is disposed at a position sandwiching the precursor space with respect to the nozzle and exhausts the plasma generation gas over time, the plasma generation gas in the space is switched. To change the direction of flow.

A plasma processing method according to a twelfth aspect is the plasma processing method according to the tenth aspect, wherein when at least one first valve is in an open state, at least one of the first valves is in a closed state. The second valve of the two nozzles is opened, and the combination of the nozzle in which the first valve is open and the nozzle in which the second valve is open is switched over time, so that The direction in which the plasma generating gas flows is changed.

According to a thirteenth aspect of the present invention, there is provided the plasma processing method according to the eleventh aspect, wherein the supply of the plasma generating gas from the plurality of nozzles is started at a predetermined interval and in order. Is a time at least twice as long as the interval.

A plasma processing method according to a fourteenth aspect is the plasma processing method according to the twelfth aspect, wherein the first valve is opened at predetermined intervals and in a predetermined order.
One open time of the first valve is at least twice as long as the interval.

According to a fifteenth aspect of the present invention, in the plasma processing method of the eighth aspect, the introduction of the plasma generating gas is arranged at a side of the space and an injection port is provided inside the space. A plurality of exhaust nozzles dedicated to exhaust gas are injected into the space by a plurality of air supply nozzles dedicated to supplying the gas for plasma generated arranged toward the space, and the exhaust gas is arranged with the suction port facing the inside of the space. This is performed by exhausting the plasma generating gas in the space by the nozzle.

A plasma processing method according to a sixteenth aspect is the plasma processing method according to the fifteenth aspect, wherein at least one of the plurality of supply nozzles and one of the plurality of exhaust nozzles are provided. The direction in which the plasma generating gas flows in the space is changed by switching the combination of the nozzle and at least one exhaust nozzle arranged at a position sandwiching the space with time over time.

A plasma processing method according to a seventeenth aspect is the plasma processing method according to the sixteenth aspect, wherein the supply of the plasma generating gas from the plurality of air supply nozzles is started at a predetermined interval and in an order. 1 from the air supply nozzle
The gas supply time is twice as long as the interval.

According to the present invention, a plasma generating gas is supplied to a space sandwiched between two electrodes, and the plasma generating gas in the space is exhausted from a direction different from the supply direction. By introducing a plasma generating gas between the electrodes and changing the flow of the plasma generating gas in the space, a uniform supply of the plasma generating gas is achieved even under the plasma processing conditions of a narrow electrode distance and high pressure. It can be performed.

[0024]

(Embodiment 1) FIG. 1 is a cross-sectional view of a plasma processing apparatus according to Embodiment 1 of the present invention, FIG. 2 is a plan view of the plasma processing apparatus, and FIG. FIG. 4 is a block diagram of a control system, FIG. 4 is a plan view of the plasma processing apparatus, FIG. 5 is an explanatory view of a process of the plasma etching process, and FIG. 6 is a timing chart showing a valve opening / closing operation in the plasma etching process. 8 is a partial plan view of the plasma processing apparatus.

First, the configuration of the plasma processing apparatus will be described with reference to FIG. In FIG. 1, an opening 1 a is provided in the lower chamber 1, and a lower electrode 3 is mounted in the opening 1 a from below through an insulating member 2. The upper chamber 4 is in airtight contact with the lower chamber 1 from above.
An upper electrode 6 is mounted on the lower surface of the upper chamber 4. The upper electrode 6 and the lower electrode 3 are two electrodes arranged in a substantially flat shape and facing each other.

An upper chamber 4 in which an upper electrode 6 is mounted;
The space enclosed by the lower electrode 3 and the lower chamber 1 is a substrate 7 which is a work held in a posture in which the surface to be processed is opposed to the lower surface of the lower electrode 3 and the lower surface of the upper electrode 6.
Is a processing chamber 5 for performing plasma etching on the surface to be processed by plasma discharge. The upper chamber 4 is connected to the lower chamber 1 via a hinge (not shown). By rotating the upper chamber 4 around the hinge, the processing chamber 5 is opened and closed, and the substrate 7 is loaded into the processing chamber 5 and after the processing. The substrate can be unloaded from the processing chamber 5. The substrate 7 is mainly made of silicon or a silicon compound such as silicon oxide.

The space sandwiched between the upper surface of the lower electrode 3 and the lower surface of the upper electrode 6 generates a plasma discharge and
(Hereinafter, abbreviated as “discharge space”). The distance L between the two electrodes is
It is set to a predetermined value at the time of manufacture or adjustment of the device, and is used with the distance L fixed when the device is operated for the specified substrate 7. Here, the distance L is set to a narrow inter-electrode distance of about 5 mm.

On the upper surface of the lower electrode 3 and the lower surface of the upper electrode 6, a large number of suction holes 3a and 6a are provided, respectively, and the suction holes 3a and 6a are provided inside the lower electrode 3 and the upper electrode 6, respectively. It communicates with the provided internal holes 3b, 6b. As shown in FIG. 1, the internal holes 3b and 6b are connected to the substrate suction vacuum pump 20 via valves VV1 and VV2, respectively.
Is connected to By driving the substrate suction vacuum pump 20 with the valves VV1 and VV2 open, the substrate 7 is sucked and held on the upper surface of the lower electrode 3 and the lower surface of the upper electrode 6 by vacuum suction from the suction holes 3a and 6a. can do.

In the lower chamber 1, a number of supply / exhaust nozzles 9 are provided penetrating the side wall. As shown in FIG. 2, a large number of supply / exhaust nozzles 9 are provided radially along the periphery of the circular lower chamber 1 with the opening facing the inside of the discharge space. These nozzles 9 are arranged on the side of the discharge space and at the same height as the discharge space, and are mounted radially at an equal pitch so as to surround the periphery of the discharge space. The nozzle 9 is connected to an annular manifold 10A via a first valve VA and to an annular manifold 10B via a second valve VB, and is connected to the first valve VA and the second valve VB. Are VA1 to VA
24, VB1 to VB24. The manifold 10A is connected to the gas supply device 11 (gas supply means).
The manifold 10B is connected to an exhaust vacuum pump 13 (gas exhaust means).

The gas supply device 11 supplies a gas for generating plasma such as oxygen gas or fluorine-based gas (hereinafter simply referred to as “gas”). By driving the gas supply device 11 with the first valve VA open, the first valve VA is sandwiched between the upper electrode 6 and the lower electrode 3 in the processing chamber 5 from the opening of the nozzle 9 in the open state. Gas is injected toward the discharge space. In this case, the nozzle 9 functions as an air supply nozzle that injects and supplies gas into the discharge space.

The evacuation vacuum pump 13 performs vacuum suction in the processing chamber 5. By driving the evacuation vacuum pump 13 with the second valve VB open, the gas in the discharge space is sucked and exhausted from the opening at the tip of the nozzle 9 with the second valve open. In this case, the nozzle 9 functions as an exhaust nozzle that inhales and exhausts gas.

A pipe 14 is connected to the upper chamber 4, and the pipe 14 is connected to a vacuum gauge 15 and is connected to an atmosphere vent device 16 via a valve VV 3.
The vacuum gauge 15 detects the degree of vacuum in the processing chamber 5, and the air vent device 16 introduces air for vacuum breaking into the processing chamber 5.

When the substrate 7 is vacuum-sucked on the upper surface of the lower electrode 3 and the lower surface of the upper electrode 6, a vacuum pump 2 for sucking the substrate is used.
By sucking the suction pressure of 0 with a degree of vacuum higher than a predetermined degree of vacuum in the processing chamber 5, that is, a pressure lower than the pressure in the processing chamber 5, even if the pressure inside the processing chamber 5 is reduced, the lower electrode The substrate 7 can be held on the upper electrode 3 and the upper electrode 6 by vacuum suction.

Inside the lower electrode 3 and the upper electrode 6,
Cooling ducts 3c and 6c are provided. Conduit 3c,
6c is connected to the first and second cooling devices 17, 18, respectively. By driving the cooling devices 17 and 18,
By circulating a coolant in c and 6c, the heat generated during the plasma etching process is absorbed by the coolant and the substrate 7 is cooled. This makes it possible to perform etching on a substrate on which a circuit is already formed on one side without causing damage due to overheating.

The lower electrode 3 is electrically connected to a high frequency power supply 19 having a tuning circuit. The upper electrode 6 is grounded via the upper chamber 4, and a high frequency voltage is applied between the lower electrode 3 and the upper electrode 6 by driving the high frequency power supply 19. After vacuuming the inside of the processing chamber 5, a gas for plasma generation is supplied into the processing chamber 5 by the gas supply device 11, and a high-frequency voltage is applied while maintaining the inside of the processing chamber 5 at a predetermined pressure. A plasma discharge is generated in a discharge space between the upper electrode 3 and the upper electrode 6. In the present embodiment, under the conditions of the narrow interelectrode distance and the high discharge pressure as described above, specifically, the value of the product PL of the gas pressure P and the interelectrode distance is 2.5 to 15 [Pa · m] is performed under such conditions.

Next, the control system will be described with reference to FIG. In FIG. 3, a first valve VA1 to VA24 and a second valve VB1 to VB connected to a supply / exhaust nozzle 9 are provided.
B24, valves VV1 and VV2 connected to the substrate suction vacuum pump 20, and valve VV3 connected to the atmospheric vent device 16 are connected to the switching unit 21, respectively. The switching unit 21 drives these valves to open and close. The switching unit 21 is connected to the control device 23 via the I / O circuit unit 22. By controlling the switching unit 21 by the control device 23, the opening / closing operation of each of the valves can be controlled. Control device 2
Reference numeral 3 controls the operations of the gas supply device 11, the vacuum gauge 15, and the high-frequency power supply 19 via the signal conversion interface 24.

This plasma processing apparatus is configured as described above, and the operation will be described below with reference to the drawings. As shown in FIG. 5A, the mounting of the substrate 7 is performed with the upper chamber 4 inverted and the processing chamber opened. In this state, the substrate 7 to be processed is placed on the lower electrode 3 and the upper electrode 6. Thereafter, the substrate suction pump 20 is driven with the valves VV1 and VV2 opened. As a result, the substrate 7 is vacuum-adsorbed and held by the lower electrode 3 and the upper electrode 6.

Next, as shown in FIG. 5B, the upper chamber 4 is rotated to cover the lower chamber 1, and the processing chamber 5 is closed. Then, with the second valves VB1 to VB24 opened, the exhaust vacuum pump 13 is driven to
The inside is evacuated. Next, a gas for plasma generation is supplied from the gas supply device 11 into the processing chamber 5.

Here, the gas supply in this embodiment will be described. As described above, in the present embodiment, since the conditions for the distance between the narrow electrodes and the high discharge pressure are set as compared with the conventional plasma processing conditions, the gas is simply supplied into the processing chamber 5 as in the conventional case. Only the substrate 7 to be processed
It is difficult to evenly supply gas to each part of the surface of the substrate, particularly to supply gas to the central part surface of the substrate.

For this reason, in the present embodiment, the plasma generating gas flows from one side of the discharge space to the other side of the discharge space, thereby reliably introducing the gas for plasma generation into the center of the discharge space, and By changing the flowing direction of the plasma generating gas over time, the plasma generating gas is uniformly introduced into the narrow discharge space.

The gas introduction by the supply / exhaust nozzle 9 will be described below with reference to FIGS. 2 and 4, the valves indicated by white circles indicate valves in a closed state, and the valves indicated by black circles indicate valves in an open state. In FIG.
First valves VA1 to VA5, second valves VB12 to
Each valve of VB16 is open, and all other valves are closed. When the gas supply device 11 and the evacuation vacuum pump 13 are driven in this state, the first valve VA
Gas is injected from the opening at the tip of the nozzle 9 connected to 1 to VA5. Since the nozzle 9 is disposed with the opening at the tip facing the discharge space, the injected gas is supplied into the discharge space. By injecting gas from a plurality of nozzles 9 arranged adjacent to each other in this manner, a strip-shaped gas having a predetermined width can be supplied into the discharge space.

At the same time, the second valves VB12-VB
The gas in the discharge space is supplied from the nozzle 9 connected to the nozzle 16, that is, the nozzle 9 having the suction port on the other side opposite to the discharge port with respect to the injection port of the nozzle 9 on the one side for supplying air. Is sucked and exhausted to the outside. That is, the gas supply device 11, the exhaust vacuum pump 20, the nozzle 9, the first valve VA, and the second valve VB supply the plasma generating gas from one side of the discharge space sandwiched between the upper and lower two electrodes. In addition, it serves as gas introduction means for exhausting the plasma generating gas in the discharge space from the other side. The gas introduction means includes a plurality of nozzles 9 arranged with openings facing the inside of the discharge space.

In FIGS. 2 and 4, the gas is sucked from the direction opposite to the direction of injection by the nozzle 9. However, depending on the flow state of the gas in the discharge space, for example, the gas is sucked from another direction. The gas may be sucked from a direction oblique to the direction.

FIG. 4 shows a state in which the valve for opening and closing the nozzle 9 has been partially switched after gas supply and exhaust have been performed for a predetermined time in the state shown in FIG. That is, the first valve VA1 and the second valve VB12 are closed,
Instead, a new first valve VA6 and a second valve VB
17 is open. By this switching, the direction of introducing the plasma gas into the discharge space has moved counterclockwise by one pitch of the nozzle.

FIG. 6 is a timing chart showing the timing of opening and closing the first valve VA at this time. In FIG. 6, T indicates an interval from when the first valve VA of one nozzle 9 is opened to when the first valve VA of another adjacent nozzle 9 is opened,
Further, t indicates a time during which the first valve VA of one nozzle 9 is continuously opened, that is, a gas supply time per one time. As shown in FIG. 6, in the first embodiment, the gas supply time t is set to five times the interval T. Thereby, a steady state (timing t shown in FIG. 6)
1 and thereafter), the gas is always supplied from the five adjacent nozzles 9 as shown in FIGS.

That is, the first valve VA is opened according to a predetermined interval and order, and the gas supply time t is equal to or longer than the interval T of the valve opening operation, that is, at least twice the interval T of the gas supply by the nozzle 9. When the gas supply from one nozzle 9 is stopped, the next nozzle 9
Since the gas supply from has already started, the gas supply is always performed from two or more nozzles 9. By controlling the valve opening / closing operation in accordance with the arrangement order of the nozzles 9 arranged on the circumference, the direction of the flow of the gas injected into the discharge space changes continuously along the circumference. This valve opening / closing operation is also performed for the second valve VB, and similarly, the gas suction direction can be sequentially moved in the circumferential direction.

In this manner, the combination of opening and closing of the first valve VA and the second valve VB is sequentially switched over time by the switching unit 21 to change the gas flow direction in the discharge space over time. It is possible to do. This switching is performed by the controller 2
3 by controlling the switching unit 21.

That is, the control device 23 and the switching unit 21 shown in FIG. 3 include at least one first valve VA.
Is in the open state, the first valve VA opens the second valve VB of at least one nozzle 9 in the closed state, and the first valve VA is opened and the second valve VB is opened.
The valve VB is a changing means for switching the combination with the nozzle in the open state over time.

In other words, the control device 23 and the switching unit 21 are arranged at least at one nozzle for supplying the plasma generating gas and at a position sandwiching the discharge space with respect to the nozzle, and exhaust the plasma generating gas. This is changing means for switching the combination with at least one nozzle over time.

As described above, by changing the flow of the plasma generating gas in the discharge space with the passage of time, the gas is uniformly supplied to each part in the discharge space.
The gas for plasma generation is uniformly supplied over the entire surface of the processing target substrate 7 placed in the discharge space.

Under such conditions, the high frequency power supply 19
, And a high-frequency voltage is applied between the upper electrode 6 and the lower electrode 3 to generate a plasma discharge between the surfaces to be processed of the substrate 7 held by the upper and lower electrodes, respectively. The target surface of the substrate 7 is simultaneously subjected to plasma etching. At this time, since the gas is uniformly supplied over the entire surface to be processed, it is possible to perform the plasma etching process without variation.

Thereafter, when a predetermined discharge time has elapsed and the plasma etching process has been completed, the atmosphere is introduced into the processing chamber 5 by the atmosphere vent device 16, and thereafter, FIG.
The upper chamber 4 is opened as shown in FIG. Then substrate 7
Is released, and the processed substrate 7 is taken out. As described above, even under the conditions of the narrow electrode distance and the high discharge pressure, the plasma generating gas can be uniformly supplied to the surface of the substrate 7 to be processed, and high processing efficiency and uniform processing quality are realized. You.

As shown in FIG. 7, an annular rectifying member 30 may be arranged on the outer periphery of the discharge space.
The rectifying member 30 has a function of rectifying a gas flow injected from the nozzle 9 located outside to a uniform flow. The gas flow (indicated by an arrow a) injected from the nozzle 9 shown in FIG. 8A is a turbulent flow in a jet state as it is, but it passes through the straightening plate 30 shown in FIG. The jet is rectified and supplied to the discharge space as a more uniform gas flow (indicated by an arrow b). This allows
The plasma generation gas is more uniformly supplied to the surface to be processed, and the processing quality can be further improved.

(Embodiment 2) FIG. 9 is a sectional view of a plasma processing apparatus according to Embodiment 2 of the present invention, and FIG. 10 is a plan view of the plasma processing apparatus.

The plasma processing apparatus shown in FIG. 9 is different from the plasma processing apparatus of the first embodiment shown in FIG. 1 in that the configuration and arrangement of nozzles 9 connected to manifolds 10A and 10B are changed. Is the same as in the first embodiment. In FIG. 9, an air supply nozzle 9A dedicated for supplying a plasma generating gas is connected to the manifold 10A with the injection port directed toward the inside of the discharge space via the first valve VA, and the manifold 10B has an exhaust port. A dedicated exhaust nozzle 9B is connected via a second valve VB with the suction port facing the inside of the discharge space. The air supply nozzle 9A and the exhaust nozzle 9B are attached to the side at the same height position as the discharge space, and are arranged at an equal pitch so as to surround the discharge space. The first valve VA and the second valve VB have VA1 'to VA12' and VB, respectively.
Numbers 1 ′ to VB12 ′ are assigned.

In FIG. 10, valves indicated by black circles and white circles indicate valves in an open state and a closed state, respectively.
The first valve VA1 ', VA2', VBA ', the second valve VB7', VB8 ', VB9' are opened, and the gas supply device 11 and the evacuation vacuum pump 13 are opened with all other valves closed. By driving, the first valve VA
Air supply nozzle 9A connected to 1 ', VA2', VA3 '
Gas is injected from the
The gas in the discharge space is sucked from the exhaust nozzle 9B connected to the valves VB7 ', VB8', and VB9 ', and is exhausted to the outside.

That is, similarly to the example shown in the first embodiment, the gas for plasma generation is introduced into the discharge space, and the gas supply device 11, the exhaust vacuum pump 20, and the air supply nozzle 9 are provided.
A, the exhaust nozzle 9B, the first bulb VA, and the second bulb VB supply a plasma generating gas from one side to a discharge space sandwiched between two upper and lower electrodes, and also supply the gas in the discharge space. It is a gas introducing means for exhausting the plasma generating gas from one side with the discharge space interposed between the other side. The gas introducing means includes a plurality of gas supply nozzles 9A dedicated to gas supply arranged with the injection port facing the inside of the discharge space, and the exhaust gas arranged with the suction port facing the inside of the discharge space. It has a plurality of exclusive exhaust nozzles 9B.

By controlling the opening and closing of the first valve VA and the second valve VB, the direction of gas supply from the air supply nozzle 9A and the exhaust nozzle 9 are controlled in the same manner as in the first embodiment.
The direction of the gas exhaust from B, that is, the direction in which the plasma generating gas flows in the discharge space can be changed over time. Therefore, the control device 23 and the switching unit 21 are configured to control at least one of the plurality of supply nozzles 9A and the plurality of exhaust nozzles 9A.
B, the combination with at least one exhaust nozzle 9B disposed at a position sandwiching the discharge space with respect to the air supply nozzle 9A is switched over time, so that the plasma generating gas in the discharge space is changed. It is a means of changing the flow over time.

Here, in switching between the first valve VA for supplying the plasma generating gas from the air supply nozzle 9A and the second valve VB for discharging the gas,
A switching pattern substantially similar to the example shown in FIG. 6 of the first embodiment is used. In the second embodiment, 3
Since gas is supplied from the two air supply nozzles 9A, the gas supply time is set to be three times the interval of each valve opening operation.

As described above, by separately providing the air supply nozzle 9A and the exhaust nozzle 9B, the flow of the plasma generating gas in the discharge space can be changed over time as in the example shown in the first embodiment. Can be. As a result, the gas is uniformly supplied to each part in the discharge space, and the gas for plasma generation is uniformly supplied over the entire surface of the processing target substrate 7 placed in the discharge space.

[0061]

According to the present invention, a plasma generating gas is supplied from one side of a discharge space to a discharge space sandwiched between two electrodes, and the plasma generating gas in the discharge space is supplied to one side. To discharge the plasma from the other side of the discharge space, introduce the gas for plasma generation between the electrodes, and change the flow of the gas for plasma generation in the space. Even under the plasma processing conditions, a uniform plasma generation gas can be supplied, and uniform plasma processing can be realized with high processing efficiency.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a plasma processing apparatus according to a first embodiment of the present invention.

FIG. 2 is a plan view of the plasma processing apparatus according to the first embodiment of the present invention.

FIG. 3 is a block diagram of a control system of the plasma processing apparatus according to the first embodiment of the present invention;

FIG. 4 is a plan view of the plasma processing apparatus according to the first embodiment of the present invention.

FIG. 5 is a process explanatory view of a plasma etching process according to the first embodiment of the present invention;

FIG. 6 is a timing chart showing a valve opening / closing operation in the plasma etching process according to the first embodiment of the present invention;

FIG. 7 is a partial plan view of the plasma processing apparatus according to the first embodiment of the present invention;

FIG. 8 is a partial plan view of the plasma processing apparatus according to the first embodiment of the present invention.

FIG. 9 is a sectional view of a plasma processing apparatus according to a second embodiment of the present invention.

FIG. 10 is a plan view of a plasma processing apparatus according to a second embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 3 lower electrode 5 processing chamber 6 upper electrode 7 substrate 9 nozzle 9A air supply nozzle 9B exhaust nozzle 10A, 10B manifold 11 gas supply device 13 exhaust vacuum pump 19 high-frequency power supply 21 switching unit 23 control device VA first valve VB second The valve

Continued on the front page (72) Inventor Tetsuhiro Iwai 1006 Kazuma Kadoma, Kazuma, Osaka Prefecture F-term (reference) 4K057 DA16 DB06 DD01 DE10 DE20 DM02 DM37 DM38 5F004 AA01 BA07 BB13 BB20 BB25 BB28 BC02 BC03 CA02 CA08

Claims (17)

[Claims] A work is arranged on at least one of two electrodes arranged opposite to each other, and a high-frequency voltage is applied between the two electrodes, whereby a plasma is formed in a space sandwiched between the two electrodes. A plasma processing apparatus for performing surface treatment of a work by generating a plasma generation gas from one side to a space interposed between the two electrodes and supplying the plasma generation gas in the space to the space. Gas introduction means for exhausting from the other side sandwiching the space with respect to one side, and changing the direction of flow of the plasma generation gas in the space by changing the plasma generation gas supply position and the exhaust position by the gas introduction means. A plasma processing apparatus, comprising: a changing means for changing. 2. The plasma according to claim 1, wherein said gas introducing means includes a plurality of nozzles arranged on a side of said space and arranged with an opening directed inside said space. Processing equipment. 3. A plurality of nozzles each having a first valve and a second valve, each of which is connected to gas supply means for supplying the plasma generating gas via the first valve, 3. The plasma processing apparatus according to claim 2, wherein the plasma processing apparatus is connected to a gas exhaust unit that exhausts the plasma generation gas via a second valve. 4. The method according to claim 1, wherein the changing means includes at least one of the plurality of nozzles for supplying a plasma generating gas and a position sandwiching the space with respect to the nozzle.
3. The plasma processing apparatus according to claim 2, wherein a combination with at least one nozzle for exhausting the plasma generation gas is switched over time. 5. The changing means opens a second valve of at least one nozzle with the first valve closed when the first valve of at least one nozzle is open. The nozzle with the first valve open and the second valve
4. The plasma processing apparatus according to claim 3, wherein the combination with the nozzle whose valve is in the open state is switched over time. 6. The gas introducing means is provided with a plurality of air supply nozzles dedicated to supply gas for plasma generation arranged with the injection port facing the inside of the space, and with the suction port facing the inside of the space. The plasma processing apparatus according to claim 1, further comprising a plurality of exhaust nozzles dedicated to exhaust. 7. The changing means is disposed at a position sandwiching the space with respect to at least one of the plurality of air supply nozzles and the air supply nozzle among the plurality of exhaust nozzles. 7. The plasma processing apparatus according to claim 6, wherein a combination with at least one exhaust nozzle is switched over time. 8. A work is arranged on at least one of two electrodes arranged to face each other, and a high frequency voltage is applied between the two electrodes, so that a plasma is formed in a space sandwiched between the two electrodes. A plasma processing method for performing a surface treatment of a workpiece by generating a plasma generation gas from one side to a space sandwiched between the two electrodes and supplying the plasma generation gas in the space. By exhausting the gas from one side to the other side, the gas for plasma generation flows into the space from one side to the other side by exhausting the space from the other side, and the flow direction of the gas for plasma generation in this space changes over time. A plasma processing method characterized by changing. 9. The method according to claim 8, wherein the introduction of the plasma generating gas is performed by a plurality of nozzles arranged on the side of the space and having openings directed to the inside of the space.
The plasma processing method as described above. 10. A plasma generating gas is supplied to said plurality of nozzles by gas supply means connected via a first valve, and said plurality of nozzles are supplied by a gas exhaust means connected via a second valve. The plasma processing method according to claim 9, wherein the gas is exhausted. 11. At least one nozzle for supplying a plasma generating gas among the plurality of nozzles, and at least one nozzle disposed at a position sandwiching a precursor space with respect to the nozzle and exhausting the plasma generating gas. 10. The plasma processing method according to claim 9, wherein the direction in which the plasma generating gas flows in the space is changed by switching the combination of the combinations over time. 12. When at least one first valve is open, a second valve of at least one nozzle with the first valve closed is open, and the first valve is open. 2. A flow direction of a plasma generation gas in the space is changed by switching a combination of the nozzle and the nozzle in a state where the second valve is in an open state over time.
0. The plasma processing method according to item 0. 13. A supply of plasma generating gas from said plurality of nozzles is started at a predetermined interval and order,
The plasma processing method according to claim 11, wherein one gas supply time from each nozzle is at least twice as long as the interval. 14. The apparatus according to claim 1, wherein the first valve is opened in a predetermined interval and in a predetermined order, and a single opening time of the first valve is at least twice as long as the interval. Item 13. The plasma processing method according to Item 12. 15. The plasma generating gas is introduced into the space by a plurality of gas supply nozzles dedicated to supplying the plasma generating gas, which are disposed on the sides of the space and have injection ports directed toward the inside of the space. The process is performed by injecting a plasma generating gas and exhausting the plasma generating gas in the space by a plurality of exhaust nozzles dedicated to exhaust that are arranged on the side of the space and have an inlet directed to the inside of the space. The plasma processing method according to claim 8, wherein: 16. At least one of the plurality of air supply nozzles and at least one of the plurality of exhaust nozzles disposed at a position sandwiching the space with respect to the air supply nozzle. 16. The plasma processing method according to claim 15, wherein the direction of flow of the plasma generating gas in the space is changed by switching the combination of the combinations over time. 17. The supply of plasma-generating gas from said plurality of air supply nozzles is started at a predetermined interval and in a predetermined order, and one gas supply time from each air supply nozzle is at least twice as long as said interval. 17. The plasma processing method according to claim 16, wherein the time is a time.