JPH02224235A - Plasma processor - Google Patents

Abstract

PURPOSE:To enable grease to be replenished easily to the part requiring grease replenishment of a movable mechanism by providing a movable mechanism, which shifts a plasma generating mechanism inside an air-tight vessel, and a through hole, which is sealed by conductive sheet material, for grease replenishment this movable mechanism. CONSTITUTION:A processing chamber wall 19 is provided around a lower electrode 3, whereby a lower housing is formed, and above that an electromagnetic wave shield cover 21 is provided, whereby an upper housing is formed. A cylindrical sliding member 27 is provided around a gas supply pipe 9 above an upper electrode 5, and the side face can slide vertically to the electromagnetic wave shield cover 21, and the air-tightness is maintained through a packing 29. A hole 21a being a through hole for grease replenishment is provided near the thrust bearing 43 of the electromagnetic wave shield cover 21, and outside the hole 21 a conductive sheet material, for example, aluminum foil piece 22 is so stuck as to keep conductivity between it and the electromagnetic wave shield cover 21, whereby the hole 21 is shielded from electromagnetic waves. Hereby, grease can be replenished easily to the specified part of the movable mechanism.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a plasma processing apparatus.

(Prior art) An upper electrode is moved up and down by a movable mechanism to maintain a predetermined distance between the upper electrode and the lower electrode, a semiconductor substrate is held on one of the electrodes, and both are held under reduced pressure. In a plasma processing apparatus that applies a high frequency voltage between electrodes to generate plasma and etches the substrate, it is necessary to shield electromagnetic waves generated from the plasma from leaking to the outside.

Therefore, conventionally, an upper housing and a lower housing are provided around the upper electrode, a movable mechanism connected to the upper electrode, and the lower electrode, and the etching processing chamber is closed by airtightly abutting both housings. At the same time, the entire processing room was shielded.

By the way, as the movable mechanism, the following ones are known, for example. That is, the upper electrode is supported by a support member connected to a plurality of ball screws, and the rotational power of a motor fixed to the support member is synchronized with the plurality of ball screws via a plurality of sprockets and a chain. and moves the upper electrode up and down.

For example, a thrust bearing or the like is interposed between the movable part and the stationary part of such a movable mechanism, and it is necessary to periodically supply grease to such parts, ball screws, and the like.

Further, as another movable mechanism, for example, an opening/closing mechanism for load-locking the etching processing chamber is provided.

This opening/closing mechanism includes a lid that closes the side surface of the etching chamber, and a mechanism that airtightly holds the lid on the side surface of the etching chamber.

In the above mechanism, metal such as SK steel is used for the rotation hinge, such as the rotation bearing.

(Problems to be Solved by the Invention) However, as described above, the upper housing is provided around the movable mechanism.

It is difficult to replenish grease to the above-mentioned thrust bearings, ball screws, etc., and for example, it has been difficult to replenish grease without taking the trouble of partially disassembling the device.

Furthermore, when metal is used in the etching chamber, it is sputtered by plasma, causing dust generation.

The present invention was made to solve such problems,
The first objective is to provide a plasma processing apparatus that can easily replenish grease to parts of a movable mechanism that require grease replenishment.

A second object of the present invention is to provide a plasma processing apparatus that prevents dust generation within an etching processing chamber.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention includes a movable mechanism for moving a plasma generation mechanism within an airtight container, and a sealing system using a conductive sheet material for replenishing the movable mechanism with grease. The movable mechanism is characterized in that the movable mechanism is provided with a through hole, and an electromagnetic shield provided to electromagnetically shield the movable mechanism.

Further, at least the rotating portion of the movable mechanism is made of a ceramic member.

Furthermore, the present invention is characterized in that at least the rotating portion of the movable mechanism is made of a fluororesin-based portion.

(Function) In the present invention, during plasma processing, the through holes provided in the electromagnetic shield are electromagnetically shielded by a conductive sheet material, so by grounding the electromagnetic shield, electromagnetic waves generated by plasma etc. can be reliably blocked. is shielded by.

In addition, when replenishing grease to a predetermined part of the movable mechanism, by removing the conductive sheet material that electromagnetically shields the through hole, it becomes possible to insert a grease injection device into the hole, and the vicinity of the through hole becomes possible. It is possible to easily replenish grease to the predetermined portions located in the area.

Furthermore, by providing the rotating part with a ceramic member, dust generation can be prevented in the airtight container.

(First Embodiment) An embodiment in which the apparatus of the present invention is applied to a plasma processing apparatus will be described below with reference to the drawings.

A grounded lower electrode 3 is provided on a support member 1 provided on the device main body. An upper electrode 5 connected to a high frequency power source 4 is provided above the lower electrode 3 and facing the lower electrode 3 . The upper electrode 5 has a hollow structure, has a large number of gas passage holes 7 on the surface facing the lower electrode 3, and is connected to a gas supply pipe 9 for supplying a reaction gas via an insulating member 8.

The gas supply pipe 9 is selectively connected to a reaction gas supply device 11 and a nitrogen gas supply device 13. Reaction gas supply device 1
The reaction gas supply from 1 is controlled by a reaction gas valve 15. The nitrogen gas supply from the nitrogen gas supply device 13 is controlled by a nitrogen gas valve 17 .

A processing chamber wall 1 made of aluminum is arranged around the lower electrode 3.
9 is provided to form a lower housing. An electromagnetic shielding cover 21 made of aluminum and having an upper electrode 5 therein is provided above the lower housing, thereby forming an upper housing.

A backing 23 is provided on the upper end surface of the processing chamber wall 19,
The lower surface of the electromagnetic shielding cover 21 is configured to be able to come into contact with it in an airtight manner.

A cylindrical sliding member 27 is provided around the gas supply pipe 9 above the upper electrode 5 . The side surface of the sliding member 27 is slidable in the vertical direction relative to the electromagnetic shielding cover 21, but by interposing the backing 29,
Airtightness is maintained.

A rectangular flat support plate 31 is provided on the upper end surface of the sliding member 27 and around the gas supply pipe 9 . Connecting arms 33 are fixed to the four corners of the support plate 31.

A motor 35 is fixed to one of the four connecting arms 33, and a support shaft 37 is fixed to the other connecting arm 33.

A rotating rod 39 is vertically connected to a rotating shaft (not shown) of the motor 35, and is also vertically connected to a bearing (not shown) of the support shaft 37. Each rotating rod 39 passes through the support plate 31 and further extends through the support plate 31.
A bearing 32 is interposed between the two. A ball screw 41 is formed at the bottom of each rotating rod 39 . The ball screw 41 is fixedly installed through the lower part of the electromagnetic shielding cover 21.

On the other hand, a thrust bearing 43 is provided around the rotating rod 39 in contact with the lower surface of the support plate 31. A sprocket 45 is provided around the rotating rod 39 in contact with the lower surface of the thrust bearing 43. Each sprocket 45 is connected by a chain 47. Therefore, in conjunction with the rotation of the motor 35, the four ball screws 41
operate in synchronization.

Further, in the vicinity of the thrust bearing 43 of the electromagnetic shielding cover 21, there is provided a hole 21a which is a through hole for grease replenishment into which a grease pressure outlet 63a of a grease injector 63 (FIG. 2) can be inserted. A conductive sheet material, such as a piece of aluminum foil 22, is adhered to the outside of the hole 21a while maintaining conductivity between it and the electromagnetic shielding cover 21.
1a is electromagnetically shielded.

An exhaust gas pipe 49 is provided at the lower part of the processing chamber wall 19, and the exhaust gas pipe 49 is connected to a vacuum pump 51. on the other hand.

A pressure detection pipe 53 for introducing the pressure inside the processing chamber is provided on the side surface of the processing chamber wall 19, and is connected to a pump switch 57 via a detection pipe valve 55. The pump switch is connected to the vacuum pump 51, detects the pressure in the processing chamber when the detection tube valve 55 is released, and determines whether the pressure is at a predetermined pressure value (for example, 1.03 (10-"Torr) or not). to control the operation of the vacuum pump 51.

Next, the operation of this etching apparatus will be explained.

First, the motor 35 is operated by a motor control device (not shown), the upper electrode 5 is moved in the vertical direction, and the distance between the upper electrode 5 and the lower electrode 3 is adjusted to a state suitable for etching.

In addition, the processing chamber is filled with 1.0x10 by the vacuum pump 51.
-''Torr. Detection and control of this atmospheric pressure value is performed by the pump switch 57.

Next, the semiconductor substrate 61 is carried by a transport means (not shown) from a vacuum preliminary chamber (not shown), which has been previously depressurized in the same manner as the processing chamber, and placed on the lower electrode 3 in the processing chamber.

Here, the reaction gas is supplied into the reaction chamber from the reaction gas supply device 11 via the gas supply pipe 9 and the gas passage hole 7 .

Then, a high frequency voltage is applied from the high frequency power source 4 to the upper electrode 5, plasma is generated from the first reaction gas, and the semiconductor substrate 61 is etched.

Thereafter, the etched semiconductor substrate 61 is transported by a transport means (not shown) to a vacuum preliminary chamber (not shown) which has been previously depressurized in the same manner as the inside of the processing chamber.

Such operations are repeated for each individual semiconductor substrate.

During the etching process as described above, the hole 21a provided in the electromagnetic shielding cover 21 is electromagnetically shielded by the aluminum foil piece 22, so by grounding one of the upper and lower housings, it is possible to prevent the generation of plasma etc. The electromagnetic waves caused by the
Grease pressure outlet 63a of grease injector 63 (Fig. 2)
can be inserted, and the thrust bearing 43 located near the hole 21 can be easily replenished with grease. After replenishing the grease, insert the aluminum foil piece 22 again into the hole 21a as before.
The material is pasted on the outside of the surface to make it ready for subsequent etching.

Note that when cleaning the inside of the processing chamber with nitrogen gas during maintenance, the gas inside the reaction chamber is exhausted by the vacuum pump 51, and the gas supply pipe 9. Nitrogen gas is supplied into the reaction chamber through the gas passage hole 7.

Furthermore, by lifting the upper housing using an opening/closing mechanism (not shown), inspection of the inside of the processing chamber can be easily performed.

Thus, in this embodiment, during the etching process, the hole 21a provided in the electromagnetic shielding cover 21 is electromagnetically shielded by the aluminum foil piece 22. On the other hand, when replenishing the thrust bearing 43, the aluminum foil piece 22 is removed. By this, the grease injector 6 is inserted into this hole 21a.
No. 3 grease pressure outlet 63a can be inserted, and the thrust bearing 43 can be easily supplied with grease.

Note that by rotating the motor 35 by an appropriate amount.

Other parts of the movable mechanism that require grease replenishment (eg, bearing 32, rotating rod 39, ball screw 41, etc.) can also be arranged near hole 21a to replenish grease.

Furthermore, it goes without saying that if there are multiple parts of the movable mechanism that require grease replenishment, multiple through holes may be provided accordingly.

In this example, a piece of aluminum foil was used as the conductive sheet material in consideration of corrosion resistance, economic efficiency, ease of attachment and detachment, etc., but the material is not limited to this. Any member can be used as long as it can be shielded.

In the above embodiment, an example was explained in which the apparatus of the present invention was applied to a plasma etching apparatus, but any apparatus that performs plasma processing may be used.

(Second Embodiment) Hereinafter, another embodiment in which the apparatus of the present invention is applied to a plasma etching apparatus having an opening/closing opening provided on the side surface of a processing chamber will be described with reference to the drawings.

The processing section of the plasma etching apparatus has already been described in the first embodiment, so a description thereof will be omitted.

Furthermore, the same parts as those described in the first embodiment will be described using the same reference numerals.

The processing chamber of the plasma etching apparatus includes a pair of upper and lower electrodes (2) and (2) for generating plasma, and an opening/closing mechanism (66) that opens and closes when loading and unloading the wafer (64) into the processing chamber (65). ) is provided.

This opening/closing mechanism (66) is provided on the opposite side of the processing chamber (65).

This opposite side has a square hole 1, for example, length 180mm x width 50mm.
A square hole (67) of m is drilled, and this square hole (67)
A backing (68) is incorporated into the treatment wall (19) at the periphery of the treatment wall (19). An airtight door (69) for closing the square hole (67) through this backing (68), for example, an airtight door (69) made of anodized aluminum material, is 200mm long x 60mm wide x 11mm thick x 9m thick. Each of them is provided.

When this airtight door (69) is arranged to close the square hole (67), it is divided into a surface in contact with the atmosphere and a surface inside the processing chamber (65). This inner surface has an opening/closing mechanism (6
6) is provided.

This opening/closing mechanism (66) is provided with a joint (71) so that the middle part of the gate ring part (70) is bent into a dogleg shape.

Since the joint (17) is bent into a dogleg shape, the airtight door (69) is provided with a through hole on the side of the processing chamber (65), that is, a transfer port for loading and unloading the wafer (64).

The above-mentioned indirection (71) is provided at one place on the block (72) provided near the inner surface of the airtight door (69), one place in the middle mentioned above, and one place on the fixed part (73) side, in total. There are three locations. Furthermore, the above indirect (71)
is composed of a shaft (74) and a bush (75).

The shaft (74) has, for example, a diameter of 3 mm and a length of 10 mm.
It is provided with an nc+ ceramic member or the like. The bush (75) has an inner diameter of 3.1 mm and a length of 10 + o.
It is made of o+ fluororesin, such as Teflon.

Furthermore, a fixing part (73) into which this fluororesin is fitted
, the link (76), and the block (72) are made of ceramic material, Teflon, or the like.

Next, the opening/closing operation of the airtight door will be explained.

First, as explained in the first embodiment, the distance between the upper electrode 0 and the lower electrode 2 is adjusted to a state suitable for etching.

In order to transfer the wafer (64) to the lower electrode 0 described above, the airtight door (69) is opened by manual air power from an air mechanism (not shown).

After this opening, the wafer (64) is placed on the lower electrode (2) via a transport mechanism (not shown) and temporarily fixed physically.

Then, in order to make the inside of the processing chamber (65) airtight, the airtight door (69) is closed, and the inside of the processing chamber (65) is depressurized to 1.0×10-” Torr by a vacuum pump (not shown). , is applied to etch the wafer (64).

Table 1 compares the particles generated in the processing chamber (65) when the movable mechanism disposed in the processing chamber (65) is made of ceramics, Teflon, or a Teflon compound material.

Table-1 (2μm diameter particles) In addition, the durability of each plastic is compared in Table 2.

Table-2 The above test conditions are as follows.

Wafer size: 5 inches, processing time = 5 minutes Processing chamber pressure 800mTorr, electric crab 250W Plasma type: 02/CF gas 150150SCCM Plasma irradiation time = 4 hours Plasma irradiation as shown in the above coating-1, Table-2 time is 1
Plasma processing can be performed in a processing chamber with less dust if the processing time is within that time.

Although the movable part of the airtight door has been described in the above embodiment, the same effect can be obtained even if the vertical drive mechanism of the first embodiment is made of ceramic material and fluororesin.

〔Effect of the invention〕

As described above in detail, according to the present invention, the through hole provided in the electromagnetic shield is electromagnetically shielded by the conductive sheet material during plasma processing, while when replenishing grease to a predetermined part of the movable mechanism, By removing the conductive sheet material that electromagnetically shields the through hole, it becomes possible to insert a grease injection device into the hole, and plasma treatment allows easy replenishment of grease to the predetermined portion near the through hole. equipment can be provided.

Furthermore, since dust generation is prevented, high-precision plasma processing becomes possible.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram for explaining one embodiment in which the apparatus of the present invention is applied to a plasma etching apparatus, and FIG.
A partial cross-sectional explanatory diagram for explaining the state when grease is supplied from the hole 21a of the plasma etching apparatus shown in the figure. FIG. 4 is a partially enlarged explanatory diagram for explaining the gate link section of FIG. 3. FIG. 21... Electromagnetic wave shield cover 21a... Hole portion 22... Aluminum foil piece 3
9... Rotating rod 41... Ball screw 43... Thrust bearing 74... Shaft 75... Bush book diagram

Claims (4)

[Claims] (1) In an apparatus that generates plasma in an airtight container for processing, a movable mechanism that moves the plasma generation mechanism that generates the plasma within the airtight container, and a conductive sheet material for replenishing the movable mechanism with grease. 1. A plasma processing apparatus comprising: a through hole sealed by a plasma processing apparatus; and an electromagnetic shield provided to electromagnetically shield the movable mechanism. (2) In an apparatus that applies a high frequency voltage between opposing electrodes in an airtight container to generate plasma and performs an etching process using the plasma, a screwing mechanism for relatively moving the opposing electrodes, and this screwing mechanism. 1. A plasma processing apparatus comprising: a through hole sealed with a conductive sheet material for supplying grease to the plasma processing apparatus; and an electromagnetic shield provided to electromagnetically shield the screw mechanism. (3) A plasma processing apparatus according to claim 1, characterized in that at least the rotating portion of the movable mechanism is made of a ceramic member. (4) A plasma processing apparatus according to claim 1, characterized in that at least the rotation of the movable mechanism is constructed from a fluororesin-based member.