JP2003332311A - Plasma treatment equipment and plasma treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide plasma treatment equipment and a plasma treatment method for preventing thin work, in particular from being damaged and broken when returning the pressure in a vacuum chamber from a vacuum pressure (low pressure) to ordinary pressure (atmospheric pressure). <P>SOLUTION: A gas flow rate adjusting means 9 is provided for resuming the atmospheric pressure in the vacuum chamber, by introducing a gas thereinto after the plasma treatment of a thin silicon wafer in the vacuum chamber. The gas flow rate adjusting means consists of a small amount supply path 9c and a large amount supply path 9e which is connected in parallel, and the former is provided with a first valve 9a, consisting of a throttle valve and a second valve 9b, and the latter is provided with a third valve 9a. When the first valve 9a is opened, a small amount of gas is supplied to the vacuum chamber 1; when the internal pressure increases and reaches a pressure which will not damage the silicon wafer 6, a third valve 9d is opened to supply a large amount of gas to the vacuum chamber 1, in order to resume the atmospheric pressure, as soon as possible. <P>COPYRIGHT: (C)2004,JPO

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 plasma processing on a workpiece such as a silicon wafer, particularly a thin plate-like substrate.

[0002]

2. Description of the Related Art In the process of manufacturing a plate-shaped substrate such as a silicon wafer used for a semiconductor device, a plate-shaped substrate is etched by a plasma processing apparatus for thinning the plate-shaped substrate or for surface treatment. In plasma processing, the plate-shaped substrate is placed on the placement part in the vacuum chamber, the inside of the vacuum chamber is vacuum-sucked to reduce the pressure to a pressure close to the vacuum pressure, and then plasma is generated in the vacuum chamber. Then, the ions and the like are caused to collide with the surface of the plate-shaped substrate. When the plasma processing is completed, the inside of the vacuum chamber is returned to normal pressure, and the processed plate-shaped substrate is taken out of the vacuum chamber.

[0003]

In the vacuum chamber of the plasma processing apparatus, after the plasma of the plate-like substrate is processed, it is returned to normal pressure by supplying gas such as air or nitrogen gas to the inside of the plasma, and then the plasma is processed. The processed plate-shaped substrate is taken out from the vacuum chamber.

The lower surface of the plate-shaped substrate on the mounting portion is vacuum-sucked and fixed by suction holes formed in the mounting portion. Therefore, when the pressure in the vacuum chamber is returned from the vacuum pressure (low pressure) to the normal pressure as described above, a large gas pressure acts on the upper surface of the plate-shaped substrate in the direction of pressing the plate-shaped substrate to the adsorption holes. An impact force is generated in the cross-sectional direction of the portion of the plate-shaped substrate that is vacuum-sucked in the suction hole. On the other hand, the plate-shaped substrate tends to be thinner in recent years, and a thickness of about 100 μm has been revealed, and it is expected that the thickness will be further reduced in the future. Therefore, in particular, in the case of such a thin substrate, it is greatly damaged by the impact force, and in the worst case, it is locally deformed or broken at the suction hole portion.

In view of the above circumstances, the present invention takes into consideration the above circumstances, and when the pressure in the vacuum chamber is returned from vacuum pressure (low pressure) to normal pressure, the work such as a thin plate-like substrate is damaged or broken. It is an object of the present invention to provide a plasma processing apparatus and a plasma processing method capable of solving the above problems.

[0006]

To this end, a plasma processing apparatus according to the present invention is a plasma processing apparatus for performing plasma processing on a work in a vacuum chamber, and includes a mounting portion on which the work is mounted, and Vacuum holding means for vacuum-sucking a work by holding it in the mounting part by vacuum suction through a suction hole opened in the mounting part; vacuum suction means for vacuum-sucking the inside of the vacuum chamber; A plasma generating means for generating a plasma for processing the workpiece placed on the vacuum chamber; and a gas supplying means for supplying a gas into the vacuum chamber to return the inside of the vacuum chamber to a normal pressure after the plasma processing. The gas supply means has a flow rate adjusting means for adjusting the flow rate of the gas supplied into the vacuum chamber, and the flow rate adjusting means allows the inside of the vacuum chamber after plasma processing. The flow rate of the gas supplied, and so a large amount of switching from a small amount.

Further, the plasma processing method of the present invention is a plasma processing method for performing plasma processing in a state where a work is held on a mounting part in a vacuum chamber, and is a mounting step of mounting the work on the mounting part. And, the work is vacuum-sucked and held on the mounting part by vacuum suction through the suction hole opened in the mounting part, and the inside of the vacuum chamber is vacuum-sucked by the vacuum suction means to reduce the pressure. Process,
A plasma processing step in which plasma is generated in the vacuum chamber to perform plasma processing on the work, and when the plasma processing is completed, the vacuum suction in the vacuum chamber by the vacuum suction means is stopped and a gas supply means is provided. To decrease the flow rate of the gas supplied to the vacuum chamber to gradually increase the inside of the vacuum chamber toward normal pressure, and then switch the flow rate of the supplied gas from a small amount to a large amount, thereby changing the inside of the vacuum chamber. Rapidly returning to normal pressure.

According to the present invention, when the plasma processing of the work is completed in the vacuum chamber, the gas is supplied little by little into the vacuum chamber to gradually increase the internal pressure. When there is no risk of the work being damaged by the gas pressure, the flow rate of the gas is increased and the pressure in the vacuum chamber is rapidly increased to the normal pressure. Therefore, the work is not damaged by the gas pressure when the inside of the vacuum chamber is returned to normal pressure, and it is extremely useful especially for plasma processing of a thin plate-like substrate of 100 μm or less.

[0009]

1 is a block diagram of a plasma processing apparatus according to a first embodiment of the present invention, FIG.
3 is a cross-sectional view of a work placing portion of the plasma processing apparatus according to Embodiment 1 of the present invention, FIG. 3 is a cross-sectional view of the plasma processing apparatus according to Embodiment 1 of the present invention, and FIG. 4 is Embodiment 1 of the present invention. 5 is a configuration diagram of a gas flow rate adjusting means in FIG. 5, FIG. 5 is a flow chart of a plasma processing method in the first embodiment of the present invention, and FIGS. 6 and 7 are process explanatory diagrams of the plasma processing method in the first embodiment of the present invention. FIG. 8 is a partially enlarged cross-sectional view of the silicon wafer and the suction hole according to the first embodiment of the present invention.

First, the plasma processing apparatus will be described with reference to FIGS. In FIG. 1, the inside of a vacuum chamber 1 is a processing chamber 2 for performing plasma processing, and inside the processing chamber 2, a lower electrode 3 and an upper electrode 4 are vertically opposed to each other. The lower electrode 3 is attached to the vacuum chamber 1 in an electrically insulated state by a support portion 3a extending downward, and the upper electrode 4 is electrically connected to the vacuum chamber 1 by a support portion 4a extending upward. It is installed.

An insulating layer 5 made of ceramic such as alumina is formed on the upper surface of the lower electrode 3, and the upper surface of the insulating layer 5 is a mounting surface on which a silicon wafer 6 (FIG. 2) which is a workpiece to be processed is mounted. Has become. Therefore, the lower electrode 3
A work surface is provided with a mounting surface on which the plate-shaped substrate is mounted. Here, the silicon wafer 6 is in a state after the back side of the circuit forming surface has been mechanically polished, and is placed with the circuit forming surface facing downward. At this time, a protective tape made of resin may be attached to the circuit formation surface.
Then, the mechanically polished surface, which is the back surface of the circuit forming surface, is plasma-treated to remove the damaged layer generated by the polishing process. The silicon wafer 6 is thin and has a thickness of, for example, 100 μm or less.

In FIG. 1, a gate valve 1a for loading and unloading a work is provided on the side surface of the vacuum chamber 1, and the gate valve 1a is opened and closed by a gate opening / closing mechanism (not shown). An exhaust pump 8 which is a vacuum suction means is connected to the vacuum chamber 1 via a valve opening mechanism 7, and the valve opening mechanism 7 is opened so that the exhaust pump 8 is opened.
Is driven, the inside of the processing chamber 2 of the vacuum chamber 1 is evacuated to a low pressure close to the vacuum pressure.
On the other hand, when the processing chamber 2 is returned to normal pressure (atmospheric pressure), a gas such as air or nitrogen gas is introduced into the processing chamber 2 from the gas flow rate adjusting means 9 through the pipe 22 to break the vacuum.

FIG. 4 is a detailed view of the gas flow rate adjusting means 9. The gas flow rate adjusting means 9 is constituted by connecting a small amount gas supply passage 9c in which a first valve 9a and a second valve 9b are connected in series and a large gas supply passage 9e having a third valve 9d in parallel. The outlet side is connected to the pipe 22 and the inlet side is connected to the pipe 23. In the present embodiment, the vacuum chamber 1 has a gas atmosphere (air).
To introduce. Therefore, the pipe 23 serves as a gas (air) supply unit, and the pipes 22 and 23 and the flow rate adjusting unit 9 form a gas supply unit. Instead of air, other gas such as nitrogen gas may be supplied to the vacuum chamber 1,
In this case, a gas cylinder such as a nitrogen gas cylinder is connected to the pipe 23 as a gas supply unit.

The first valve 9a is, for example, a throttle valve, and the throttle is adjusted in advance so that the flow rate of gas becomes small. Therefore, the flow rate of the gas in the small amount gas supply passage 9c is smaller than the flow rate of the gas in the large gas supply passage 9e.
If the second valve 9b is opened and the third valve 9d is closed, a small flow rate (small amount) from the small amount supply passage 9c to the vacuum chamber 1
Gas is supplied at (arrow V1). The second valve 9b
Is closed and the third valve 9d is opened, gas is supplied from the large-volume supply unit 9e to the vacuum chamber 1 at a high flow rate (large amount) (arrow V2). That is, the first valve 9a serves as a flow rate regulator, and the second valve 9b and the third valve 9d serve as opening / closing means for the small amount supply passage 9c and the large amount supply passage 9e, respectively.

As shown in FIG. 2, the insulating layer 5 is provided with a large number of suction holes 5a which are open on the upper surface, and the suction holes 5a communicate with the suction holes 3b provided inside the lower electrode 3. . The suction hole 3b is connected to a vacuum adsorption pump 12 via a gas line switching opening / closing mechanism 11, and the gas line switching opening / closing mechanism 11 is connected to an N ₂ gas supply unit 13 and a He gas supply unit 14 as shown in FIG. It is connected. By switching the gas line switching opening / closing mechanism 11, the suction hole 3b can be selectively connected to the vacuum adsorption pump 12, the N ₂ gas supply unit 13, and the He gas supply unit 14.

By driving the vacuum suction pump 12 while the suction hole 3b is in communication with the vacuum suction pump 12, vacuum suction is performed from the suction hole 5a and the silicon wafer 6 placed on the upper surface of the insulating layer 5 is vacuum suctioned. Hold and fix. Therefore, the suction hole 5a, the suction hole 3b, and the vacuum suction pump 12 serve as a vacuum holding unit that vacuum-sucks the work by holding it on the mounting surface by vacuum suction from the suction hole 5a opened on the mounting surface.

Further, by connecting the suction hole 3b to the N ₂ gas supply unit 13 or the He gas supply unit 14, it is possible to eject nitrogen gas or helium gas from the adsorption hole 5a to the lower surface of the silicon wafer 6. It has become. As will be described later, the nitrogen gas is a blowing gas for the purpose of forcibly separating the silicon wafer 6 from the surface of the insulating layer 5, and the helium gas is for heat transfer used for the purpose of promoting cooling of the silicon wafer during plasma processing. Is the gas of.

In FIG. 2, the lower electrode 3 is provided with a cooling medium passage 3c for cooling, and the cooling medium passage 3c is connected to the cooling mechanism 10. By driving the cooling mechanism 10, a coolant such as cooling water circulates in the coolant channel 3c, thereby cooling the lower electrode 3 that has been heated by the heat generated during the plasma processing. The coolant channel 3c and the cooling mechanism 10 serve as a cooling unit that cools the lower electrode 3 that is the substrate mounting portion.

In FIG. 1, the lower electrode 3 is electrically connected to a high frequency power source section 17 via a matching circuit 16. By driving the high-frequency power supply unit 17, a high-frequency voltage is applied between the upper electrode 4 and the lower electrode 3 which are electrically connected to the vacuum chamber 1 grounded by the grounding unit 19, which causes plasma discharge in the processing chamber 2. Occur. The matching circuit 16 matches the impedance of the high frequency power supply unit 17 with the plasma discharge circuit that generates plasma in the processing chamber 2. The lower electrode 3, the upper electrode 4, and the high-frequency power supply unit 17 serve as a plasma generation unit that generates plasma for plasma-processing the silicon wafer 6 mounted on the mounting surface.

Here, as the plasma generating means,
Opposed parallel plate electrodes (lower electrode 3 and upper electrode 4)
Although an example of a method of applying a high-frequency voltage is shown in between, a method other than this, for example, a method of providing a plasma generator in the upper part of the processing chamber 2 and sending plasma into the processing chamber 2 by a downflow method may be used. .

A DC power supply 18 for electrostatic attraction is connected to the lower electrode 3 via an RF filter 15. By driving the DC power supply unit 18 for electrostatic attraction, as shown in FIG.
As shown in (a), negative charges are accumulated on the surface of the lower electrode 3. Then, in this state, as shown in FIG. 3B, the high-frequency power supply unit 17 is driven to generate plasma in the processing chamber 2 (see a dotted portion 20 in the drawing), so that it is placed on the insulating layer 5. A direct current application circuit 21 that connects the silicon wafer 6 and the ground portion 19 is formed via the plasma in the processing chamber 2, whereby the lower electrode 3, the RF filter 15,
A closed circuit that sequentially connects the electrostatic attraction DC power supply unit 18, the ground unit 19, the plasma, and the silicon wafer 6 is formed, and positive charges are accumulated in the silicon wafer 6.

Then, a Coulomb force acts between the negative charges accumulated in the lower electrode 3 and the positive charges accumulated in the silicon wafer 6, and this Coulomb force causes the silicon wafer 6 to move.
Are held by the lower electrode 3 via the insulating layer 5. At this time, the RF filter 15 prevents the high frequency voltage of the high frequency power supply unit 17 from being directly applied to the electrostatic attraction DC power supply unit 18. The lower electrode 3 and the DC power supply 18 for electrostatic attraction are
It is an electrostatic attraction means for holding the silicon wafer 6 which is a plate-like substrate on the mounting surface by electrostatic attraction. The polarity of the electrostatic attraction DC power supply unit 18 may be reversed.

This plasma processing apparatus is configured as described above, and the plasma processing method will be described below with reference to FIGS. 6 and 7 along the flow of FIG. In FIG. 5, first, a silicon wafer 6 as a processing target is transferred into the processing chamber 2 (ST1) and mounted on the mounting surface of the insulating layer 5 of the lower electrode 3 (mounting step). At this time, since the silicon wafer 6 is thin and easily bent, it may be mounted in a state where it is warped as shown in FIG. 6A and a gap is formed between it and the mounting surface of the insulating layer 5. . After that, the gate valve 1a is closed (ST2), and the vacuum suction pump 12 is driven to move the suction hole 5 to the suction hole 5 as shown in FIG. 6 (b).
a, vacuum suction is performed through the suction holes 3b, and the silicon wafer 6
The vacuum adsorption state of is turned on (ST3). This allows
As shown in FIG. 6C, the silicon wafer 6 is held by vacuum suction while being in close contact with the mounting surface (holding step).
The second valve 9b and the third valve 9d are closed until the plasma processing of the silicon wafer 6 is completed.

Then, the exhaust pump 8 is driven to drive the processing chamber 2
The inside of the vacuum chamber 1 is evacuated (ST4), and the inside of the vacuum chamber 1 is depressurized to near vacuum pressure. After that, the electrostatic attraction DC power supply 18 is driven to turn on the application of the DC voltage (ST5), and the high frequency power supply 17 is driven to start plasma discharge (ST).
6). As a result, as shown in FIG.
Plasma is generated in the space between the upper silicon wafer 6 and the lower surface of the upper electrode 4, and plasma processing is performed on the silicon wafer 6 (plasma processing step). In this plasma treatment, an electrostatic attraction force is generated between the lower electrode 3 and the silicon wafer 6 (see FIG. 3B), and the silicon wafer 6 is held by the lower electrode 3 by the electrostatic attraction force. . In FIGS. 3A and 3B, the silicon wafer 6 is drawn thick for convenience of description.

After that, the gas line switching opening / closing mechanism 11
To turn off the vacuum suction (ST7), and back He
Introduction is performed (ST8). That is, after the holding of the silicon wafer 6 to the lower electrode 3 by vacuum suction is released, helium gas for heat transfer is supplied from the He gas supply unit 14 through the suction holes 3b, and as shown in FIG. Then, it is ejected from the adsorption holes 5a to the lower surface of the silicon wafer 6. In this plasma treatment, the lower electrode 3 is cooled by the cooling mechanism 10, and the heat of the silicon wafer 6 which has been heated by the plasma treatment is transferred to the lower electrode 3 via the helium gas which is a gas having a high heat conductivity. As a result, the silicon wafer 6 is efficiently cooled.

When the discharge is completed after the lapse of a predetermined plasma processing time (ST9), the back He is stopped (ST10) and the vacuum adsorption is turned on again as shown in FIG. 7 (b) (ST11). . As a result, the silicon wafer 6 is held on the mounting surface by the vacuum suction force instead of the electrostatic suction force that disappears when the plasma discharge ends.
Thereafter, the electrostatic attraction DC power supply unit 18 is stopped to turn off the DC voltage (ST12), and the gas flow rate adjusting means 9 is driven to open the atmosphere to the atmospheric pressure in the processing chamber 2 (ST13). ).

Next, with reference to FIG. 4, description will be given of opening to the atmosphere for returning the inside of the vacuum chamber 1 to the normal pressure. at first,
The first valve 9a is opened and the third valve 9d is closed to reduce the flow rate of the gas from the small amount supply passage 9c to send the gas into the vacuum chamber 1 (arrow V1), and the pressure in the vacuum chamber 1 is gradually increased to normal pressure. Raise towards. And vacuum chamber 1
When the internal pressure of 7 increases to some extent, the third valve 9d is opened.
Then, the flow rate of the gas supplied into the vacuum chamber through the large amount supply passage 9e becomes large (arrow V2), and the inside of the vacuum chamber 1 rapidly returns to normal pressure. At this time, the first valve 9a
May be closed or may remain open.

The reason why the flow rate of the gas supplied to the vacuum chamber 1 is made small at first to gradually increase the internal pressure thereof and then the third valve 9d is opened to make the flow rate of the gas large is as follows. Is. That is, in FIG. 8, the silicon wafer 6 is thin (for example, about 100 μm in thickness) and is vacuum-sucked in the suction holes 5a immediately after the plasma processing is completed. If a large amount of gas is rapidly and rapidly supplied to the vacuum chamber 1 to return it to the atmospheric pressure in that state, the gas pressure P that presses the silicon wafer 6 downward rapidly increases. Therefore, as shown by the chain line, the silicon wafer 6 is damaged by being deformed so as to bend toward the suction hole 5a side, and in the worst case, the silicon wafer 6 is broken by this gas pressure P. Therefore, in order to eliminate such an inconvenience, as described above, the flow rate of the gas supplied into the vacuum chamber 1 is initially reduced to gradually increase the internal pressure, and the silicon wafer 6 may be damaged by the internal pressure. If there is no longer, the flow rate of the gas is increased and the inside of the vacuum chamber 1 is returned to atmospheric pressure as soon as possible.

As a method of setting the timing of switching the flow rate of gas to the vacuum chamber 1 from a small amount to a large amount, a method of switching from a small amount to a large amount after a preset time has elapsed, or a pressure sensor is provided in the vacuum chamber 1 and the vacuum chamber 1 If the pressure sensor detects that the internal pressure of the cylinder has risen to a predetermined pressure, a method of switching from a small amount to a large amount can be applied. It is desirable that the silicon wafer 6 be maintained in a state of being vacuum-sucked and fixed to the suction holes 5a until the inside of the vacuum chamber 1 is returned to the atmospheric pressure (normal pressure).

After this, the gas line switching opening / closing mechanism 11 is driven again to turn off the vacuum adsorption (ST1
4) Then, the wafer is blown (ST15). That is, as shown in FIG. 7C, nitrogen gas is supplied through the suction holes 3b and ejected from the adsorption holes 5a. This allows
The silicon wafer 6 is separated from the mounting surface of the lower electrode 3. Then, the gate valve 1a is opened (ST1
6) If the silicon wafer 6 is transferred to the outside of the processing chamber 2 (ST17), the wafer blow is turned off (ST1).
8) Then, one cycle of plasma treatment is completed.

As described above, in the plasma processing shown in this embodiment, the plasma is generated in the processing chamber 2 and the lower electrode 3 of the silicon wafer 6 is held until the electrostatic attraction force is generated. This is done by vacuum adsorption. As a result, even when a thin and flexible plate-like substrate such as the silicon wafer 6 is targeted, the silicon wafer 6 can always be brought into close contact with the mounting surface of the lower electrode 3 and appropriately held. Therefore, in the case of poor adhesion, it is possible to prevent abnormal discharge that occurs in the gap between the upper surface of the lower electrode 3 and the lower surface of the silicon wafer 6 and overheating of the silicon wafer 6 due to poor cooling.

(Second Embodiment) FIG. 9 is a block diagram of a gas flow rate adjusting means in a second embodiment of the present invention. The flow rate adjusting means 90 is formed by connecting an opening / closing valve 90a and a control valve 90b in series between the pipe 22 and the pipe 23. The throttle of the control valve 90b is controlled in two steps, in multiple steps, or steplessly by a command from a control unit (not shown). The configuration other than the flow rate adjusting means 90 is the same as that of the first embodiment.

Therefore, when the plasma processing is completed and the inside of the vacuum chamber 1 is returned to the normal pressure, the opening / closing valve 90a is opened and the control valve 90b is slightly opened to reduce the flow rate of the gas into the vacuum chamber 1. , The pressure in the vacuum chamber 1 is gradually increased toward normal pressure. When the internal pressure of the vacuum chamber 1 rises to some extent, the control valve 90b is opened wide to increase the flow rate of the gas sent into the vacuum chamber 1. As a result, the inside of the vacuum chamber 1 quickly returns to normal pressure.

As is apparent from the above-described embodiments, the gas flow rate adjusting means can be modified in various ways. The point is that the flow rate of the gas supplied to the vacuum chamber can be switched from a small amount to a large amount. Good.

Although the embodiments of the present invention have been described above, the present invention can be carried out in various modified forms other than the above-mentioned embodiments. For example, the cooling means for cooling the lower electrode 3 which is the mounting portion, and the heat transfer gas supply means for supplying the heat transfer gas to the adsorption holes 5a may be omitted as necessary. The holding of the plate-shaped substrate by the vacuum suction means may be continued during the plasma processing step, that is, while the electrostatic attraction means holds the plate-shaped substrate. Furthermore, while nitrogen gas is used as the gas for wafer blowing, other gas such as air may be used.

Plasma treatment may be performed with a resin protective tape attached to the circuit forming surface of the silicon wafer 6. In this case, this protective tape is used as an insulating layer instead of the insulating layer 5 of the lower electrode. You may use it.

[0037]

According to the present invention, particularly when a pressure in the vacuum chamber is returned from a vacuum pressure (low pressure) to a normal pressure (atmospheric pressure), a thin plate-like substrate is damaged or broken. Can be resolved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a plasma processing apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a work mounting portion of the plasma processing apparatus according to the first embodiment of the present invention.

FIG. 3 is a sectional view of the plasma processing apparatus according to the first embodiment of the present invention.

FIG. 4 is a configuration diagram of a gas flow rate adjusting unit according to the first embodiment of the present invention.

FIG. 5 is a flowchart of the plasma processing method according to the first embodiment of the present invention.

FIG. 6 is a process explanatory diagram of the plasma processing method according to the first embodiment of the present invention.

FIG. 7 is a process explanatory diagram of the plasma processing method according to the first embodiment of the present invention.

FIG. 8 is a partially enlarged cross-sectional view of a silicon wafer and a suction hole according to the first embodiment of the present invention.

FIG. 9 is a configuration diagram of a gas flow rate adjusting unit according to a second embodiment of the present invention.

[Explanation of symbols]

1 vacuum chamber 2 processing room 3 Lower electrode 4 Upper electrode 6 Silicon wafer 8 exhaust pump 9,90 Flow rate adjusting means 9a first valve 9b Second valve 9c Small amount supply path 9d 3rd valve 9e Large amount supply path 12 Vacuum adsorption pump 22,23 pipe

Claims (4)

[Claims] 1. A plasma processing apparatus for performing plasma processing of a work in a vacuum chamber, comprising vacuum suction through a mounting portion on which the work is mounted and a suction hole opened in the mounting portion. Vacuum holding means for vacuum-sucking and holding the work on the mounting portion, vacuum suction means for vacuum sucking the inside of the vacuum chamber, and generating plasma for processing the work placed on the mounting portion. A plasma supply means, and a gas supply means for supplying a gas into the vacuum chamber to return the inside of the vacuum chamber to a normal pressure after the plasma treatment, wherein the gas supply means supplies a gas to the vacuum chamber. It has a flow rate adjusting means for adjusting the flow rate, and by this flow rate adjusting means, the flow rate of the gas supplied into the vacuum chamber after plasma processing is switched from a small amount to a large amount. The plasma processing apparatus characterized by. 2. The flow rate adjusting means has a small quantity supply path and a large quantity supply path which are arranged in parallel, the small quantity supply path has a flow rate adjuster and opening / closing means for the small quantity supply path, and the large quantity supply path opens and closes. The plasma processing apparatus according to claim 1, further comprising means. 3. A plasma processing method for performing plasma processing in a vacuum chamber while holding a work on a mounting part, comprising: a mounting step of mounting the work on the mounting part; A step of vacuum-sucking the work by vacuum suction through the opened suction hole and holding it on the mounting portion, and a step of vacuum-sucking the inside of the vacuum chamber by vacuum suction means to reduce the pressure; And a plasma treatment step of performing plasma treatment of the work by generating plasma in the vacuum chamber, and when the plasma treatment is completed, the vacuum suction in the vacuum chamber by the vacuum suction means is stopped and the vacuum chamber is controlled by the gas supply means. The flow rate of the gas supplied to the inside of the vacuum chamber is gradually raised toward normal pressure by decreasing the flow rate of the gas supplied to the inside of the vacuum chamber. The plasma processing method characterized by including the step of returning rapidly to atmospheric pressure the vacuum chamber by switching. 4. When the gas is supplied to the inside of the vacuum chamber by the gas supply means and the inside of the vacuum chamber is returned to normal pressure, the work by the vacuum holding means is vacuum-sucked and held by the mounting portion. The plasma processing method according to claim 3, wherein the plasma processing method is maintained.