JPH06275528A - Exhaust part structure of vacuum processor - Google Patents

Abstract

PURPOSE:To accelerate the effective exhaust rate for enhancing the flexibility of the process requirements without increasing the volume of a processing chamber by a method wherein a port for assembling a valve body is separately prepared on the side of a duct part while a driving part lifting the valve body is provided adjacently to the processing chamber. CONSTITUTION:A part of a processing chamber 6 is protruded rightward to form an exhaust duct part 6a. Next, a cylinder 7 and the driving shaft 8 of the cylinder 7 is provided on the upper part of the exhaust duct 6a through the intermediary of a sealing flange. Next, the valve body 9 assembled through a maintenance port 10 fitted to the side of the exhaust duct 6a is fitted to the end of the driving shaft 8. Besides, a part of the valve body 9 has a protrusion 9a. On the other hand, a valve seat 6b for sealing an exhaust port is formed on the surface of the processing chamber 6 opposing to the valve body 9. Next, the suction port flange 13a of a pressure regulating valve case 12 and a turbo molecular pump 13 is fitted to the rear surface of the valve seat 6b. Finally, an exhaust tube 14 is assembled into the exhaust port 13b of the turbo molecular pump 13 so as to be exhausted by a roughing vacuum pump.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a vacuum evacuation means for performing plasma processing such as plasma CVD (chemical vapor deposition), etching and sputtering, and film forming processing such as vapor deposition and thermal CVD. More particularly, the present invention relates to a vacuum processing apparatus having a main valve that seals an intake port of an exhaust means and a pressure adjusting valve that is provided to adjust a processing pressure.

[0002]

2. Description of the Related Art An example of a simplified structure of the exhaust means of a conventional vacuum processing apparatus is disclosed in Japanese Patent Laid-Open No. 64-1964.
There is No. 7870. Further, as examples showing the mechanism of the pressure regulating valve, there are, for example, JP-A-55-119171 and JP-A-3-115260.

In recent vacuum processing equipment, the pressure to be processed is shifting to the high vacuum side more and more. Therefore, when the equipment is made, the exhaust system is constructed, the construction method and the mechanism are evacuated to the high vacuum. It has become important to be careful. That is, when the processing in the molecular flow region of a 10- ⁴ Torr stand, as well as keep the exhaust conductance large capacitor having a large engine - the adoption of a high vacuum pump such as a turbomolecular pump is required . Also, Japanese Patent Laid-Open No. 64-21
No. 080 has an example in which a plurality of exhaust pumps are provided to improve the exhaust speed. However, providing a plurality of exhaust pumps is costly and disadvantageous to reliability. There is also a problem that the device becomes large. Further, the exhaust conductance is actually largely dependent on the method of manufacturing the device from the surface of the substrate to be processed to the exhaust pump, but this point is not mentioned at all.

[0004]

By the way, in the vacuum processing apparatus, in order to reduce the impurity gas mixed into the processing substrate during processing, the process processing chamber is once evacuated to high vacuum. Further, in the plasma process treatment, the treatment is performed while supplying a reactive gas and maintaining a constant pressure. In the case of single-wafer processing, in which each processing substrate such as a wafer is guided to the processing chamber and processed continuously, how fast can the vacuum be evacuated to start processing It goes without saying that it is important to increase the amount (improve the throughput). Also, etching and C
In plasma processing such as VD, it is important to control the ratio of the supplied gas and reaction by-products (impurities). For this purpose, the process gas flow rate Q can be increased while maintaining the processing pressure P constant. It is important to be able to supply to the room. In other words, it is important how much the exhaust speed S can be increased. These are physically easy Q
= P × S.

The average residence time τ, which indicates how long the supplied gas stays in the process chamber, is given by the volume V of the process chamber. Becomes At the time of etching, it is also important to discharge the reaction gas as quickly as possible in order to increase the etching rate. In other words, it is necessary to reduce this residence time τ.

The pressure P usually has an appropriate value for each treatment, and the volume V affects the performance of the apparatus.
And the exhaust speed S. In order to reduce the staying time τ, it is important to make V small and S large. It is known that also in sputtering, when the exhaust speed S is increased, the impurities in the film are reduced when compared at the same pressure.

It is an object of the present invention to provide an exhaust part structure in which the volume of the process processing chamber can be made as small as possible and the vacuum processing apparatus capable of evacuation speed can be made as large as possible.
Further, by doing so, it is to provide a device having a high exhaust speed, excellent cost performance, and compactness even if exhaust pumps of the same size are used.

[0008]

In order to achieve the above-mentioned object, a valve body is attached to the side surface of the duct portion as compared with a conventional method of assembling a main valve which is attached to the duct portion from above by using a flange larger than the valve body. A port to be assembled is separately prepared, and a drive unit for moving the valve body up and down is provided adjacent to the process processing chamber,
It was decided to assemble the valve body from the port. . This allows the volume of the process chamber to be minimized.

Further, the flapper of the pressure regulating valve for adjusting the pressure in the process gas is usually provided so as not to interfere with the main valve, but the valve body of the main valve is opened toward the retracted space. It is the one.

[0010]

After a processed substrate such as a wafer is loaded into the process chamber, the gate valve is closed to form a closed chamber for high vacuum evacuation. Since the volume is small, the time required to reach a predetermined high vacuum can be shortened. Further, since the pressure regulating valve is provided so that the exhaust speed decreases when the processing pressure for etching or the like is constant, the exhaust speed is high and the process gas flow rate can be increased.

According to the method of the present invention, the exhaust portion is compact and relatively inexpensive and has a high cost performance. The valve mechanism of the main valve collides with the flapper by using the clutch mechanism even during a power failure or emergency. This prevents the motor and gears used as the pressure regulating valve drive mechanism from being damaged by the shock generated.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 is a longitudinal sectional view of the plasma processing apparatus, and FIG. 2 is FIG.
FIG. 5 is a vertical sectional view taken along line AA of FIG.

In FIG. 1, reference numeral 1 is a waveguide, and a microwave generation source (not shown) is attached to the tip. Two
Is a solenoid coil, and 3 is an introduction window for separating microwave from the atmosphere and guiding the microwave into the vacuum, which is made of an insulating material. Reference numeral 4 is a metal cylinder that forms a discharge chamber 5. Reference numeral 6 denotes a process treatment chamber, a part of which is projected rightward to form an exhaust duct portion 6a. A cylinder 7 and a drive shaft 8 for the cylinder 7 are provided above the exhaust duct portion 6a via a sealing flange 11. A valve body 9 is attached to the tip of the drive shaft 8 from a maintenance port 10 attached to the side surface of the exhaust duct portion 6a. In the present embodiment, a part of the valve body 9 is a protrusion 9
a. A valve seat 6b for sealing the exhaust hole is formed on the surface of the process processing chamber 6 facing the valve body 9. The pressure regulating valve case 12 and the intake hole flange 13a of the turbo molecular pump 13 are attached to the back surface side of the valve seat 6b. An exhaust tube 14 is attached to the exhaust hole 13b of the turbo molecular pump 13, and is exhausted by a roughing pump (not shown). A shaft 15 penetrating from the atmosphere is passed through the pressure regulating valve case 12, and a flapper 16 is attached to the shaft 15.
Is attached, and a roller 17 is attached to the tip thereof. The shaft 15 is held by sliding members 29 and 30, and the atmosphere side is connected to the electromagnetic clutch 24. The other end of the electromagnetic clutch 24 is connected to a gear 27 and a motor 28 supported by a bracket 26 and the like. Reference numeral 18 is a gate valve, and 19 is a transfer chamber. Reference numeral 20 denotes an electrode, which is provided so as to project upward from the lower surface of the process processing chamber 6 and has a wafer 21 mounted on its tip. The electrode 20 not only can move up and down as a whole, but also has a function for cooling the wafer 21, a wafer pushing mechanism for carrying and a high frequency bias applying mechanism (neither is shown). Reference numeral 23 is a process gas supply pipe, which is schematically shown.

In the present embodiment, the valve body 9, the pressure regulating valve case 12 and the flapper 16 have a square shape that is a substantially square shape, but they may have a circular shape. Further, although the exhaust duct 6a is formed in the lower portion of the process processing chamber 6, the exhaust duct 6a is formed as it is at the height of the internal opening of the gate valve 18 without vertically driving the entire electrode 20, in other words, in other words. The exhaust duct portion 6a may be provided at the same height as the electrode 20 and the wafer 21. In this embodiment, a solenoid coil 2 for obtaining a magnetic field
Therefore, the processing chamber is simply shaped as shown in FIG. In the case of another parallel plate type process chamber, it goes without saying that the exhaust duct portion 6a can be formed at a position substantially the same as the height of the wafer 21 as described above. Further, instead of the turbo molecular pump 13, a cold trap, a cryopump, an oil diffusion pump or the like may be provided. further,
The valve body 9 may be operated by another drive mechanism that does not depend on the cylinder 7.

Next, the operation of each section in this embodiment will be described. The wafer 21 carried by the carrier means (not shown) from the carrier chamber 19 through the gate valve 18 is shown in FIG.
As shown in FIG. 5, the electrode 20 mounted on the tip of the electrode 20 is lifted and held. Close the gate valve 18, the process treatment chamber 6 from sealing to form a closed chamber is evacuated to a high vacuum (10- ⁷ Torr base) once with a turbo molecular pump 13.
At this time, the valve body 9 is held at the uppermost position, and the flapper 16 is also opened to the fully open position 6 shown by the chain line in FIG.
3 makes it possible to smoothly exhaust the inside of the process processing chamber 6. Next, the process gas whose flow rate is controlled by the gas supply pipe 23 is introduced into the discharge chamber 5, and the flapper 16 is rotated and held by the motor 28 so as to have a predetermined processing pressure. Introducing a predetermined process pressure (several Torr~10- ⁴ Torr) after reaching microwave, to generate microwave plasma by interaction of the magnetic field by the electric field and the solenoid coil 2, utilizing the plasma ions and radicals Then, the wafer 21 is processed. The pressure adjustment during this processing can be performed by controlling the turning position of the flapper 16. In this embodiment, the open loop control by the pulse motor is performed based on the signal of the pressure measuring means (not shown), but other control methods may be used.

After the processing is completed, the supply of the microwave and the process gas through the gas supply pipe 23 is stopped, and immediately after that, the flapper 16 is swung to the fully open position to exhaust the residual gas. After that, the wafer 21 is unloaded from the process chamber 6 by performing the reverse operation. At the time of production, this operation is repeated to continually continue the processing.

Although the normal operation of the apparatus is carried out as described above, according to the present invention, the valve body 9 is attached adjacent to the discharge chamber 5 and the volume of the process chamber 6 is reduced. And the flapper 16 is driven in the space created by the valve body 9 retreating upward, so the pressure regulating case 12 can be made thinner without the need for another retreating space.
It is possible to suppress a decrease in the exhaust speed of the turbo molecular pump 13. As a result, in this embodiment, the high vacuum evacuation time before and after etching can be shortened by about 30% as compared with the conventional apparatus. Further, when the pressure is set to be the same as the pressure during the processing of the apparatus having the exhaust portion according to the conventional method, the apparatus of the present embodiment can flow the supplied gas amount by about 2.5 times.

This results in increased flexibility in process conditions,
In addition to facilitating optimization of processing conditions, it has become possible to shorten the processing time of the device and improve throughput. Furthermore, the mechanism is simple and the reliability against dust generation is not impaired at all.

By the way, in an emergency such as a sudden pressure increase due to a power failure or damage to the introduction window 3, the turbo molecular pump 1
In order to prevent backflow of the compressed gas on the back pressure side of 3 into the process processing chamber 6 and to protect the turbo molecular pump 13, it is usual to operate the cylinder 7 and lower the valve body 9 to close it. In this case, the grip of the electromagnetic clutch 24 is released, and the shaft 15 is allowed to rotate freely. When the valve body 9 of the main valve descends, the projection 9a comes into contact with the roller 17 provided at the tip of the flapper 16 and pushes the flapper 16 down to the fully closed position. This prevents damage to the gear 27 and the motor 28 due to impact or the like.

When carrying out maintenance inside the process chamber 6, there is a case where the valve 9 is lowered and sealed while the turbo molecular pump 13 is kept in vacuum to return the process chamber 6 to the atmospheric pressure. At this time, if the flapper 16 is lowered to the fully closed position a in advance and then the valve body 9 is lowered,
The purpose can be achieved without causing the valve body 9 and the flapper 16 to interfere with each other.

A sensor mechanism for knowing the fully open or fully closed position may be provided on the atmosphere side of the shaft 15, and the counterweight may be provided on the atmosphere side in order to reduce the unbalanced load moment due to the flapper 16 of the shaft 15. Alternatively, it may be provided in a vacuum. Further, the electromagnetic clutch 24 may be replaced by a clutch of another system or, in an extreme case, a torque limiter. Further, instead of using one shaft 15, a plurality of shafts may be attached to each of them, and a mechanism for operating simultaneously or individually may be provided on the atmosphere side.
8 may be a motor or power of another system.

[0022]

As described above, according to the present invention, the effective evacuation rate is improved without increasing the volume of the processing chamber, the flexibility of the process conditions is increased, and the cost performance is excellent and the reliability is high. A highly compact exhaust part structure can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of a plasma processing apparatus showing an embodiment of the present invention.

FIG. 2 is a vertical sectional view taken along the line AA of FIG.

[Explanation of symbols]

6 ... Process processing chamber, 7 ... Cylinder, 9 ... Valve body, 10 ...
Maintenance port, 11 ... Sealing flange, 12 ... Pressure regulating valve case, 13 ... Turbo molecular pump, 15 ... Shaft, 16 ...
Flapper, 17 ... Roller, 24 ... Electromagnetic clutch, 27 ... Gear, 28 ... Motor.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kenji Nakata, 794, Higashitoyoi, Higashi-Toyoi, Shimomatsu, Yamaguchi Prefecture, Ltd. Inside the Kasado Plant, Hitachi, Ltd. Company Hitachi Ltd. Kasado factory

Claims (4)

[Claims] 1. A device for subjecting a workpiece such as a wafer to plasma processing or vacuum processing at the time of vapor deposition in a vacuum, and means such as a turbo molecular pump for exhausting a process gas from a process processing chamber during process processing. Alternatively, there is provided a means for temporarily evacuating the process treatment chamber to a high vacuum before performing the process treatment, and a main valve for partitioning the intake port of the exhaust means from the process treatment chamber is provided as a part of the process treatment chamber. In the vacuum processing apparatus having a structure in which the valve seat of the main valve is sealed by driving the valve body of the main valve in the exhaust duct part, To assemble the valve body from the side of the exhaust duct part by making the area of the valve seat of the intake port of the exhaust means larger than the opening area of the exhaust duct mounting part of the drive part facing each other. Vent structure of the vacuum processing apparatus according to claim provided maintenance port to the exhaust duct, in that a main valve by close contact with the process treatment chamber. 2. A pressure regulating valve for adjusting the processing pressure of the process processing chamber during the processing of the process is disposed directly below the valve seat,
The flapper of the pressure regulating valve is opened in the space of the exhaust duct where the valve body of the main valve is retracted to regulate the pressure, thereby shortening the distance between the valve seat of the main valve and the intake port of the exhaust means. The exhaust part structure of the vacuum processing apparatus according to claim 1. 3. The pressure regulating valve according to claim 2, wherein a clutch mechanism is provided in a drive unit on the atmosphere side for rotationally driving the flapper shaft of the pressure regulating valve, and when the valve body of the main valve is closed, the clutch mechanism contacts the flapper of the pressure regulating valve. In this case, the flapper of the pressure regulating valve is pushed down, and at this time, the clutch mechanism disconnects the rotary shaft of the flapper of the pressure regulating valve from the gear and the motor of the drive unit. 4. An exhaust part structure of a vacuum processing apparatus, characterized in that claim 1 and claims 2 and 3 are combined.