JPH10280153A - Plasma cvd device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma CVD device capable of improving treating efficiency and furthermore improving the quality of coating film to be formed by removing generated reaction products without fluctuating the pressure at the inside of a chamber. SOLUTION: A work 73 is placed to fix to the surface of a stage 75 freely rotatably provided at the inside of an air-tightly held chamber 3, evacuation is executed by an exhausting device 85, a gas fed by a gas feeding device 81 is converted into plasma by a high-frequency applying means 55, reaction products generated at the time of forming coating on the work 73 are scattered to the side outer than a rotary plate 37 rotated in a lower chamber 21 provided on the lower side of the chamber 3 and are received by a pan 25. Since this pan 25 is provided so as to be freely attached/ detached at the lower chamber 21, the pan 25 is detached, and the reaction products are removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma CVD apparatus, and more particularly, to a plasma CVD apparatus characterized in removing a product generated in a chamber.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Application Laid-Open No. 8-2601
As described in Japanese Patent Application Publication No. 54-54, a plasma CVD apparatus is provided with a stage for mounting a wafer on which a film is to be formed on a lower lid provided on a lower side of a chamber, and equipment such as a gas supply device. That is common.

Therefore, in order to remove a reaction product that has fallen on the inner surface of the chamber or the lower lid of the chamber when forming a film, the lower lid is generally removed for cleaning and removal.

[0004] As described in Japanese Patent Application Laid-Open No. Hei 8-260153, a stage for mounting a film to be formed on an upper lid of a chamber is provided, and a high frequency applying means is provided on a lower lid. There is also a structure, but also in this case, in order to remove the reaction product, it is necessary to remove the lower lid on which the high-frequency applying means is installed and perform cleaning and removal.

[0005]

However, in such a plasma CVD apparatus, it is difficult to remove and attach the lower lid because the lower lid is provided with a stage, a gas supply device, a high frequency applying means and the like. In addition, there is a problem that it is difficult to remove a reaction product falling on the lower lid.

In addition, since the film must be formed in a highly evacuated environment, if the lower lid is removed and the reaction products are removed, the evacuation must be performed again, and the processing efficiency decreases. is there.

Further, when a plurality of wafers are continuously formed without removing the reaction products, the reaction products deposited in the lower portion of the chamber are scattered due to pressure fluctuations caused by switching of valves and the like. There is a possibility that the film quality may be deteriorated.

SUMMARY OF THE INVENTION An object of the present invention is to pay attention to the prior art described above, and to reduce the pressure inside a chamber during or after a film formation process by using unnecessary reaction products generated by plasma CVD. It is an object of the present invention to provide a plasma CVD apparatus capable of improving processing efficiency and improving the quality of a formed film by removing the film without changing the same.

[0009]

In order to achieve the above object, a plasma CVD apparatus according to the first aspect of the present invention comprises a chamber provided so as to be able to maintain airtightness, and a work placed inside the chamber. A stage rotatably provided in a fixed state, an exhaust device for exhausting the inside of the chamber, a gas supply device capable of supplying a desired amount of a reaction gas to the inside of the chamber, and a gas supply device. What is claimed is: 1. A plasma CVD apparatus comprising: a high-frequency application unit for converting a reaction gas into plasma, comprising: a lower chamber provided in a lower side of the chamber so as to be able to maintain airtightness; and a rotation chamber rotatably provided in the lower chamber. A plate, and a receiving tray that receives the reaction product scattered outward by the rotating plate and is detachably provided in the lower chamber. It is.

Therefore, the work is placed and fixed on a stage rotatably provided in the airtightly maintained chamber, and the work is evacuated by the exhaust device, and the gas supplied by the gas supply device is subjected to high frequency power. Unnecessary reaction products generated when a film is formed on the work by being turned into plasma by the application means are received by a rotating plate rotating in a lower chamber provided on the lower side of the chamber and scattered outward and downward, and are scattered by a receiving plate. receive. Since the tray is detachably provided in the lower chamber, the tray is removed to remove the reaction product.

According to a second aspect of the present invention, a gate valve is provided between the chamber and the lower chamber, wherein the gate valve can be shut off while the chamber and the lower chamber are kept airtight. That is, it is characterized.

Therefore, since the gate valve completely shuts off the chamber from the lower chamber, the internal pressure of the chamber does not fluctuate even when the tray in the lower chamber is removed.

According to a third aspect of the present invention, there is provided the plasma CVD apparatus according to the first or second aspect, wherein a vacuum pump is provided in the lower chamber.

Therefore, after removing the reaction pan by removing the pan, the pan is attached and the lower chamber is evacuated by a vacuum pump.

According to a fourth aspect of the present invention, there is provided the plasma CVD apparatus according to the first, second or third aspect, wherein a heating means and a cooling means are provided on a side wall of the chamber. is there.

Therefore, by alternately operating the heating means and the cooling means, the reaction products adhering to the inner wall of the chamber are peeled off.

According to a fifth aspect of the present invention, there is provided a plasma CVD apparatus according to the first, second, third or fourth aspect, wherein the inner diameter of the lower chamber is larger than the inner diameter of the chamber. It is.

Therefore, since the inner diameter of the chamber is smaller, there is no lifting of the reaction product from the lower chamber due to the centrifugal force of the rotating plate.

According to a sixth aspect of the present invention, there is provided a plasma CVD apparatus according to the first, second, third, fourth or fifth aspect.
In the D apparatus, the upper surface of the rotating plate is inclined downward toward the peripheral portion.

Therefore, the reaction product that has fallen on the rotating plate slides down toward the peripheral portion along the slope, and is scattered outward and downward from the rotating plate by centrifugal force.

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a plasma CVD according to the present invention.
Apparatus 1 is shown. In the plasma CVD apparatus 1, a chamber 3, which is a reaction chamber, is provided at a central portion.
The side wall 5 of the chamber 3 has a double structure for passing a cooling pipe 7 serving as a cooling means and a heater 9 serving as a heating means to enable temperature adjustment. However, on the lower side, the gate valves 13 are sealed by O-rings 15 and the like, respectively, and are provided so as to be airtight.

Below the gate valve 13, there is provided a lower chamber 21 consisting of an inner chamber 17 having an open upper side and an outer chamber 19 which is located outside the inner chamber 17 and has upper and lower sides. Since the outer chamber 19 is connected to the outside of the inner chamber 17 by three to four thin connecting members 23, falling objects from above fall in the outer chamber 19.

Below the outer chamber 19, there is provided a ring-shaped tray 25 which can be slid and fixed in the vertical direction along the outer peripheral surface of the inner chamber 17. It is attached to the lower side of the chamber 19 and the outer peripheral surface of the inner chamber 17 in a state of maintaining airtightness. Accordingly, the receiving tray 25 can be easily removed by removing the bolt 29 and sliding the receiving tray 25 downward with respect to the lower chamber 21.

A bearing unit 31 is provided below the inner chamber 17, and a rotating shaft 33 rotatably supported by the bearing unit 31 is provided through the center of the inner chamber 17 in the up-down direction. ing. A seal 35 such as a magnetic fluid seal unit or a magnetic bearing is provided on the bottom wall 17A of the inner chamber 17 through which the rotating shaft 33 penetrates, so that the airtightness of the lower chamber 21 is ensured.

At the upper end of the rotating shaft 33, a rotating plate 37 is provided so as to cover the opening of the inner chamber 17.
The upper surface of the rotating plate 37 is provided with an inclination such that the center is higher and becomes lower toward the periphery. Also,
The inner diameter of the outer chamber 19 is slightly larger than the inner diameter of the side wall 5 of the chamber 3 from the viewpoint of preventing the reaction products from being rolled up.

On the other hand, a flat gear 39 is provided at the lower end of the rotating shaft 33.
Is mounted, and a motor 43
It is connected to. An auxiliary exhaust pipe 45, which is a vacuum pump, is provided vertically through the bottom wall 17A of the inner chamber 17, and is connected to an auxiliary pump 49 via a valve 47.

The upper lid 11 is provided with an opening 51 having the same size as the inner diameter of the chamber 3, and is provided with a quartz dielectric window 53 covering the entire opening 51 from above. Above the dielectric window 53, a copper ring-shaped antenna 55 as a high-frequency applying means is provided. The ring-shaped antenna 55 is connected to a matching box 59 by a terminal 57, and further connected to a high-frequency power supply 61. I have.

The dielectric window 53 may be made of a material other than quartz, such as alumina, which transmits radio waves but does not transmit infrared rays. Although the ring-shaped antenna 55 is not cooled in FIG.
May be made of a tubular material so that cooling water can flow through the inside so that it can be cooled.

Further, a pipe 63 for supplying oxygen (O ₂ ) gas is provided in the upper lid 11, and a supply path 65 is connected to the pipe 63. The distal end of the supply path 65 is opened directly below the dielectric window 53, and the dielectric window 5 is opened.
Oxygen gas is supplied to the vicinity immediately below 3.

On the other hand, at the center position inside the chamber 3,
A motor 69 is attached by three to four connecting members 67 protruding from the inner surface of the side wall 5 into the chamber 3.
A rotating shaft 71 of the motor 69 is provided vertically at a center position of the chamber 3, and a sample stage 75 on which a silicon wafer 73 as a workpiece to be processed is mounted is mounted on an upper end of the rotating shaft 71. Have been.

The outside of the motor 69 is casing by a motor case 77, and the rotary shaft 71 and the motor case 77 are kept airtight by a seal 79 such as a magnetic fluid seal unit or a magnetic bearing.

Above the sample stage 75, a gas supply pipe 81 made of, for example, a quartz ring is used as a gas supply device.
A point on the ring of the gas supply pipe 81 is connected to the branch pipe 83. The branch pipe 83 penetrates the side wall 5 of the chamber 3 by a union joint (not shown) and is connected to a SUS pipe (not shown). Thus, the gas supply pipe 81 blows out the sample gas supplied from the branch pipe 83 toward the inside of the ring.

An exhaust pipe 85 as an exhaust device is provided on the side wall 5 of the chamber 3. A turbo-molecular pump 87 and a rotary pump 89 are connected to the exhaust pipe 85 to exhaust the inside of the chamber 3.

Next, the operation of the above-described inductively coupled plasma CVD apparatus 1 and a film forming method will be described.

First, the silicon wafer 73 is placed and fixed on the sample stage 75 inside the chamber 3 by a loader (not shown). Here, if the inside of the chamber 3 is at atmospheric pressure, the gas is exhausted from the exhaust pipe 85 by the turbo molecular pump 87 and the rotary pump 89, for example, from 10 ^-6 to 1
Vacuum to about 0 ^-7 Torr. At this time, the gate valve 13 is kept open and the valve 47 is kept closed.

Next, the motor 69 is started to rotate the sample stage 75 at a predetermined rotation speed, and further the motor 43 is started to rotate the rotation plate 37 at a predetermined rotation speed. And a dichlorosilane gas (SiH ₂ Cl ₂ ) is supplied from the gas supply pipe 81 at a predetermined ratio.

After the pressure inside the chamber 3 is adjusted to a predetermined pressure by a slot valve (not shown) or the like, high-frequency power is supplied to the ring antenna 55 from the terminal 57 via the matching box 59. As a result, the supplied oxygen is excited, and an oxygen plasma 91 is formed immediately below the dielectric window 53 and flows downward. Then, dichlorosilane gas (SiH ₂ Cl ₂ ) supplied in the vicinity of the sample stage 75 is decomposed and synthesized by the oxygen plasma 91, and an SiO ₂ film is deposited on the silicon wafer 73.

The reaction product generated during the film formation and falling to the lower part of the chamber 3 is scattered outward and downward by the centrifugal force of the rotating plate 37 and is constantly collected in the ring-shaped tray 25. At this time, since the inner diameter of the lower chamber 21 is larger than the inner diameter of the side wall 5 of the chamber 3, the reaction product is prevented from being wound up by centrifugal force.

The deposited film thickness may be confirmed in-situ (on the spot) or may be controlled by time. When the film formation is completed, the high-frequency power supply 61 is turned off, the supply of oxygen gas (O ₂ ) and dichlorosilane (SiH ₂ Cl ₂ ) gas is stopped, and these gases are exhausted from the exhaust pipe 85.

Next, the rotation of the sample stage 75 is stopped by stopping the motor 69. While maintaining the vacuum, the silicon wafer 73 is taken out of the chamber 3 by a loader (not shown). Thereafter, the heating and quenching of the side wall 5 are repeatedly performed by the heater 9 and the cooling pipe 7 provided on the side wall 5 of the chamber 3, whereby the reaction product attached to the side wall 5 is positively peeled off, and the reaction product is rotated. Drop on plate 37.
The dropped reaction product is collected in the ring-shaped tray 25 by the centrifugal force of the rotating plate 37.

After the above operation is sufficiently repeated, the motor 4
3 is stopped, and the rotating plate 37 is stopped. After closing the gate valve 13 and opening the lower chamber 21 to the atmosphere, the bolt 29 is removed, and the ring-shaped tray 25 is moved downward along the side wall of the inner chamber 17 and removed.

After removing the reaction products collected in the ring-shaped pan 25, the ring-shaped pan 25 is attached to the outer chamber 19, the valve 47 is opened, and the lower chamber 21 is opened by the auxiliary pump 49 until a predetermined pressure is reached. Vacuum. Then, valve 4
7 is closed, and the gate valve 13 is opened to complete a series of processing.

From the above results, it is possible to easily collect unnecessary reaction products while keeping the pressure inside the chamber 3 during or after the film forming process, and to take out the unnecessary reaction products to the outside of the chamber 3. Further, even when a plurality of silicon wafers 73 are successively formed, the number of bubbles generated in the film can be reduced, so that the quality of the formed film can be improved.

The present invention is not limited to the above-described embodiment, but can be embodied in other modes by making appropriate changes. That is, in the above-described embodiment, the reaction products are collected in the ring-shaped receiving tray 25 during and after the film formation, but may be collectively collected after the film formation.

In the above-described embodiment, the gate valve 13 and the auxiliary pump 49 are used. Alternatively, the chamber 3 may be opened to the atmosphere and the tray 25 may be taken out.

[0047]

As described above, in the plasma CVD apparatus according to the first aspect of the present invention, a work is mounted and fixed on a stage rotatably provided in a hermetically sealed chamber. Unnecessary reaction products generated when the gas supplied from the gas supply device is evacuated and turned into plasma by the high-frequency application means to form a film on the work are evacuated by the exhaust device, and the unnecessary reaction products are provided below the chamber. The reaction product can be received by the tray because it is scattered outward and downward by the rotating plate rotating in the room.
Since this tray is detachably provided in the lower chamber,
By removing the pan, the reaction product can be easily removed.

In the plasma CVD apparatus according to the second aspect of the present invention, since the gate valve completely shuts off the chamber and the lower chamber, the chamber is removed even when the reaction pan is removed by removing the tray in the lower chamber by closing the gate valve. Internal pressure can be maintained. Thereby, the processing efficiency can be improved.

In the plasma CVD apparatus according to the third aspect of the present invention, after removing the reaction pan by removing the pan, the pan is attached and only the lower chamber is evacuated by the evacuation pump to easily maintain the same pressure as the chamber. Can be evacuated. Thereby, the processing efficiency can be improved.

In the plasma CVD apparatus according to the fourth aspect of the present invention, the reaction product adhering to the inner wall of the chamber can be forcibly peeled off by alternately operating the heating means and the cooling means. The product can be easily removed.

In the plasma CVD apparatus according to the fifth aspect of the present invention, since the inner diameter of the chamber is smaller, it is possible to prevent the reaction product from being wound up from the lower chamber by the centrifugal force of the rotating plate.

In the plasma CVD apparatus according to the sixth aspect of the present invention, the reaction product that has fallen on the rotating plate slides down to the peripheral edge along the slope, and is scattered outward and downward from the rotating plate by centrifugal force to receive the tray. Can be more easily removed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a plasma CVD apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plasma CVD apparatus 3 Chamber 5 Side wall 7 Cooling pipe (cooling means) 9 Heater (heating means) 13 Gate valve 21 Lower chamber 25 Receiving tray 37 Rotating plate 45 Auxiliary exhaust pipe (vacuum pump) 55 Antenna (high frequency applying means) 73 Silicon Wafer (work) 75 Stage 81 Gas supply pipe (gas supply device) 85 Exhaust pipe (exhaust device)

Claims (6)

[Claims] A chamber provided so as to be able to maintain airtightness;
A stage rotatably provided inside the chamber with the work mounted and fixed thereon, an exhaust device for exhausting the interior of the chamber, and a gas supply capable of supplying a desired amount of a reaction gas into the chamber An apparatus and a plasma CVD apparatus comprising a high-frequency application unit for converting a reaction gas supplied by the gas supply apparatus into plasma.
A lower chamber provided in a lower side of the chamber so as to be able to maintain airtightness, and a rotating plate rotatably provided in the lower chamber;
A plasma CVD apparatus, comprising: a receiving plate that receives the reaction products scattered outward by the rotating plate and that is detachably provided in the lower chamber. 2. A gate valve is provided between said chamber and said lower chamber, said gate valve being capable of shutting off said chamber and said lower chamber in an airtight state.
The plasma CVD apparatus as described in the above. 3. The plasma CVD apparatus according to claim 1, wherein a vacuum pump is provided in the lower chamber. 4. A heating device and a cooling device are provided on a side wall of the chamber.
Or the plasma CVD apparatus according to 3. 5. The plasma CVD apparatus according to claim 1, wherein the inner diameter of the lower chamber is larger than the inner diameter of the chamber. 6. The plasma CVD apparatus according to claim 1, wherein an upper surface of the rotary plate is inclined downward toward a peripheral portion.