JPH08298234A - Vacuum treatment device and its operating method - Google Patents

Abstract

PURPOSE: To decrease the down time of a vacuum treatment device provided with a trap with which products are gathered in the exhaust path of the vacuum treatment device by a method wherein the exhaust path is connected to the treatment chamber where a vacuum treatment is conducted. CONSTITUTION: An exhaust tube 31 and a turbomolecular pump 41 are connected to a treatment chamber 2, and traps 6 and 7 are provided on both flow passages 50 and 60 respectively by paralleling a part of the exhaust path on the downstream side of the exhaust tube 31. At the same time, valves 51, 61, 52 and 62 are provided on both sides of he traps 6 and 7, and washing liquid feeding tubes 7 and 8, a waste fluid tube 72, dry gas feeding tubes 73 and 83, and exhaust tubes 74 and 84 are connected to the traps 6 and 7. When the traps 6 and 7 on one side are used, the valves on both sides of the other traps 6 and 7 are closed, a product is washed by feeding washing water, for example, and then the inside of the treatment chamber 2 is dried up.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum processing apparatus and its operating method.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing process, various processes such as CV are performed on a semiconductor wafer (hereinafter referred to as "wafer") by using a process gas in a vacuum atmosphere.
Processing such as D, etching, or ashing is performed. When performing such vacuum processing, reaction products based on the reaction between components in the processing gas or the reaction between components of the processing gas and components on the wafer surface are exhausted from the exhaust port of the processing chamber through the exhaust passage. However, if they adhere to the exhaust passage, the exhaust pipe, valve and vacuum pump must be cleaned. Such cleaning of the exhaust system involves troublesome work such as removal of the exhaust pipe, valve and vacuum pump, cleaning of the vacuum pump, and when the reaction product is corrosive, the exhaust pipe, etc. Therefore, it is necessary to suppress the reaction products from adhering to the exhaust system as much as possible.

Therefore, conventionally, in order to prevent the reaction products from adhering to the exhaust system, a vacuum processing apparatus has been constructed as shown in FIG. In FIG. 4, reference numeral 1 denotes an airtight processing chamber, and a wafer W mounting table 1 having a heater built in the processing chamber 1.
1 and a processing gas introduction part 12 are provided. Further, in the processing chamber 1, a turbo molecular pump 13 and a dry pump 1
An exhaust pipe 15 provided with 4 is connected, and first, the dry pump 14 is evacuated to a predetermined vacuum degree through the branch passage 16 and then the turbo molecular pump 13 is evacuated to a higher vacuum degree. The system is configured.

A trap 17 is provided on the upstream side of the turbo-molecular pump 13, and a heating means such as a tape heater is wound around the outer periphery of the exhaust passage from the exhaust port of the processing chamber 1 to the trap 17, whereby the exhaust passage is provided. To prevent the reaction products from adhering to the exhaust passage, and to force the reaction products to precipitate in the trap 17 by cooling them to a temperature below the sublimation point of the reaction products. The reaction product is prevented from adhering to it. In the figure, Va,
Vb and Vc are valves.

[0005]

By the way, although the trap 17 needs to be cleaned regularly, the wafer W cannot be processed at the time of cleaning, which causes downtime of the apparatus. When the trap 17 is washed, the trap 17 is first removed from the exhaust pipe 15, the inside is washed with a washing liquid, and then dried, and then attached to the exhaust pipe 15, so that the down time is long, which causes a decrease in throughput. There is also a problem that the work for cleaning the trap 17 is frequent.

Further, the pipe diameter of the exhaust pipe 15 between the processing chamber 1 and the turbo molecular pump 13 is, for example, about 4 to 8 inches in order to obtain a large conductance so as not to impair the exhaust capacity of the turbo molecular pump 13. Therefore, the trap 17 provided in this portion also needs to be large. If the trap 17 is arranged upstream of the turbo molecular pump 13, the water remaining in the trap 17 after cleaning flows into the processing chamber 1 to corrode the processing chamber 1 or adversely affect the processing of the wafer W. There was a risk of causing.

The present invention has been made under such circumstances, and an object thereof is to be able to perform cleaning of a trap and processing of an object to be processed in parallel, thereby improving throughput. (EN) Provided are a vacuum processing apparatus and an operating method thereof.

Another object of the present invention is to provide a vacuum processing apparatus and a method of operating the vacuum processing apparatus which can reduce the size of the trap.

[0009]

According to a first aspect of the present invention, an airtight processing chamber for introducing a processing gas to perform vacuum processing on an object to be processed in a vacuum atmosphere, and a processing chamber connected to the airtight processing chamber. In a vacuum processing apparatus having an exhaust passage, a first passage and a second passage provided in the exhaust passage and connected in parallel to each other, and the first passage and the second passage. And a first collecting part and a second collecting part, which are respectively provided in the first flow path and the second flow path, for collecting the product exhausted from the processing chamber, and the first collection part in the first flow path and the second flow path. It is characterized by comprising valves provided upstream and downstream of each of the collecting portion and the second collecting portion.

According to a second aspect of the present invention, an airtight processing chamber for introducing a processing gas to perform vacuum processing on an object to be processed in a vacuum atmosphere, an exhaust passage connected to the processing chamber, and In the vacuum processing apparatus, the first vacuum evacuation means and the second vacuum evacuation means having a larger vacuum evacuation capacity than the first vacuum evacuation means, which are sequentially provided in the exhaust passage from the downstream side, are provided. Of the first vacuum pumping means and the second vacuum pumping means, which are provided in an exhaust path between the second vacuum pumping means and are connected in parallel to each other.
And a second flow path, and a first collection part and a second collection part which are provided in the first flow path and the second flow path, respectively, and collect the product exhausted from the processing chamber. And a valve provided upstream and downstream of each of the first collecting section and the second collecting section in the first flow path and the second flow path, and the first flow path. A heating means for heating the inner surfaces of the exhaust passage on the upstream side of the collection portion and the second collection portion and the second vacuum exhaust means to a temperature equal to or higher than the temperature at which the product is deposited. It is characterized by that.

According to a third aspect of the present invention, in the vacuum processing apparatus according to the first or second aspect, the first collecting section and the second collecting section have a cooling means for precipitating a product and a collecting means. A cleaning liquid supply path and a drainage path connected to the collection chamber for cleaning the formed product with a cleaning solution, and a dry gas supply connected to the collection chamber for drying the collection chamber with a dry gas. A passage and an exhaust passage.

According to a fourth aspect of the present invention, an airtight processing chamber for introducing a processing gas to perform vacuum processing on an object to be processed in a vacuum atmosphere, an exhaust passage connected to the processing chamber, and In the vacuum processing apparatus, the first vacuum evacuation means and the second vacuum evacuation means having a larger vacuum evacuation capacity than the first vacuum evacuation means, which are sequentially provided in the exhaust passage from the downstream side, are provided. Collecting section provided in an exhaust path between the vacuum exhausting means and the second vacuum exhausting means, for collecting the product exhausted from the processing chamber, and an exhaust path upstream of the collecting section. And heating means for heating each inner surface of the second evacuation means to a temperature equal to or higher than a temperature at which the product is deposited,
It is characterized by having.

According to a fifth aspect of the present invention, there is provided an airtight processing chamber for introducing a processing gas and performing vacuum processing on the object to be processed in a vacuum atmosphere, and an exhaust passage connected to the processing chamber. In the vacuum processing apparatus, a part of the exhaust path is arranged in parallel to provide a first collection part and a second collection part in one and the other flow paths, respectively, and valves on both sides of the first collection part are provided. And a step of supplying a cleaning liquid into the first collecting section to remove the precipitated product, and then supplying a dry gas into the first collecting section to move the inside of the collecting section. It is characterized by including a step of drying and a step of evacuating the inside of the processing chamber through the second trap while the valves on both sides of the first trap are closed.

[0014]

By opening the valves on both sides of the first collection part, the gas exhausted from the processing chamber flows in the first collection part, and the reaction product in the gas flows to the first collection part. Are deposited and removed. During this time, the valves on both sides of the second collection unit are closed. When cleaning the first collection unit, the valves on both sides of the first collection unit are closed, and the valves on both sides of the second collection unit are closed. When opened, the reaction product is deposited by the second collection unit, and the first collection unit is washed during that period. In this case, if a cleaning liquid supply pipe and a dry gas supply pipe are provided in the collection unit, automatic cleaning can be performed, which is convenient. Further, if the collecting portion is provided on the downstream side of the second evacuation means, the conductance of this portion may be smaller than that on the upstream side, so that the collecting portion can be downsized, and the evacuation means can be heated. Therefore, there is no possibility that the reaction product will adhere to the vacuum exhaust means.

[0015]

1 shows a gas processing apparatus according to an embodiment of the present invention, and the gas processing apparatus of this embodiment is constructed as a single-wafer thermal CVD apparatus.

Reference numeral 2 in FIG. 1 denotes a processing chamber having an airtight seal structure for performing CVD. At the bottom of the processing chamber 2, a semiconductor wafer W to be processed is held and heated to a predetermined temperature. A wafer mounting table 21 provided with a heater 20 is provided. A processing gas supply unit 2 for supplying a processing gas into the processing chamber 2 is provided above the processing chamber 2.
2 is disposed so as to face the wafer holding table 21, and the processing gas supply unit 22 uses, for example, TiCl which is a processing gas.
The first gas supply pipe 23 for supplying ₄ gas and the second gas supply pipe 24 for supplying, for example, NH ₃ gas, which is a processing gas, are connected to the gas injection plate 25 at their tips. ing. The first gas supply pipes 23 and 24 are connected to a liquid source of TiCl ₄ and a gas supply source of NH _{3 which} are not shown. Gate valves G1 and G2 for opening and closing the carry-in / out port are provided on the side wall of the processing chamber 2.

At the bottom of the processing chamber 2, for example, a pipe diameter of 4 to
One end of an exhaust pipe 31 forming an 8-inch exhaust passage is connected, and a turbo molecular pump 41 is connected to the other end of the exhaust pipe 31 via a valve 32. To the downstream side of the turbo molecular pump 41, for example, one end of an exhaust pipe 33 forming an exhaust passage having a pipe diameter of 1 to 2 inches is connected, and the other end side of the exhaust pipe 33 is a first flow path. The dry pump 42 is connected through a parallel flow path of the exhaust pipe 50 and the exhaust pipe 60 that is the second flow path. A branch passage 34 is branched from the exhaust pipe 31, and the branch passage 34 is connected to a downstream side of the parallel flow passage via a valve 35. In this example, the dry pump 42 and the turbo molecular pump 41
Respectively form a first evacuation means and a second evacuation means.

A valve 51, a trap 5 and a valve 52 which form a first collecting portion are provided in this order from the upstream side in the first flow path 50, and the second flow path 60 has an upstream side. A valve 61, a trap 6 that forms a second collecting portion, and a valve 62 are provided in this order from the side. The first trap 5 is
As shown in FIG. 3, for example, a plurality of plate-shaped fins 5b are arranged in a plurality of rows in the collection chamber 5a so as to be orthogonal to the flow path, and each fin 5b has a plate surface of the collection chamber 5a. It is configured to face obliquely with respect to the line connecting the inlet and the outlet.

A channel 50 on the upstream side in the vicinity of the collection chamber 5a
A supply pipe 7 forming a supply portion for a cleaning liquid for cleaning the inside of the collection chamber 5a, for example, a cleaning liquid for supplying water, is provided in the inside of the collection chamber 5a. A plurality of injection holes 71 are formed to inject water toward the valve body of the upstream valve 51 and the fin 5b. Here, the flow path 50 between the collection chamber 5a and the upstream valve 51 extends, for example, in the vertical direction, and the collection chamber 5a
The nearby downstream flow path 50b extends in the vertical direction and is bent horizontally in the middle, and a drainage pipe 72 serving as a drainage part of the cleaning liquid is provided on the bottom surface of this bent portion.

Further, on the upstream side and the downstream side of the collection chamber 5a, there are provided a supply pipe 73 serving as a supply portion for the drying gas, for example, N ₂ gas, and an exhaust pipe 74 serving as an exhaust portion for the N ₂ gas. . Further, in the collection chamber 5a, there is provided a refrigerant flow pipe 75 for passing a refrigerant, for example, cooling water, and the inlet side and the outlet side (which overlap in FIG. 3) of the refrigerant flow pipe 75 are It is connected to the cooler 77 via the pipe 76.
The second trap 6 has the same configuration.

In FIG. 1, a piping system such as a cleaning supply pipe for the traps 5 and 6 is schematically shown. As can be seen from FIG. 2, the cleaning liquid supply pipe 7 (8) has a valve 53 (6).
3) is installed, and a valve 54 (64) is installed in the cleaning drain pipe 72 (82). The valve 55 (65) is interposed in the supply pipe 73 (83) of the N ₂ gas, N ₂
A valve 56 (66) is provided in the gas exhaust pipe 74 (84). Further, the pipe 76 (8
A valve 57 (67) is provided in 6). Then, exhaust pipes 31, 50, 60, valves 32, from the processing chamber 1 to the first trap 5 and the second trap 6 are provided.
51, 61 and the turbo molecular pump 41 are attached with a heating means 36, for example, a tape heater, for heating the inner wall surface of these to a predetermined temperature. The first trap 5 and the second trap 6 and the exhaust pipes 50 and 60 between the traps 5 and 6 and the valves 52 and 62 are provided with heating means 37 and 38 (Fig. 2 omitted) For example, a tape heater is attached.

Next, the operation of the above embodiment will be described. First, the processing chamber 2 is driven by the dry pump 42 through the branch passage 34.
The inside is evacuated to, for example, 1 to 5 × 10 ⁻² Torr, then the valve 35 is closed and the valve 32 is opened, and the inside of the processing chamber 2 is set to, for example, 10 ⁻⁶ to 10 ⁻⁷ To by the turbo molecular pump 41.
Evacuate to rr. After that, the gate valve G1 is opened, and an object to be processed, for example, a wafer W is loaded into the processing chamber 2 from a load lock chamber (not shown) and placed on the mounting table 21.
The wafer W is heated to a predetermined temperature, for example, 500 to 750 ° C., for example, TiCl ₄ gas and NH ₃ gas are supplied into the processing chamber 2 from the gas supply pipes 23 and 24 of the post-processing gas supply unit 22, respectively, and the turbo molecular pump is used. The surface of the wafer W is Ti
An N (titanium nitride) film is formed.

Here, the valves 51, 52 of the first flow path 50
Is open, the gas in the processing chamber 2 is
Through the turbo molecular pump 41 to the first flow path 50 side, and is exhausted to the outside by the dry pump 42 via the exhaust pipe 33. In the processing chamber 2, in addition to TiN, NH ₄ Cl
(Ammonium chloride) is generated as a reaction by-product,
The exhaust gas is exhausted into the exhaust pipe 31, but the upstream side of the first trap 5, that is, the exhaust pipe 31, the valve 32, the turbo molecular pump 41, the first flow passage 50, and the inner surface of the valve 51 are heated by the heater 36 to emit NH ₄ gas. Temperature above the sublimation temperature of Cl, eg 1
By heating to 50 to 180 ° C., NH ₄ Cl becomes a gas state during this period and enters the first trap 5. In the first trap 5, since the inside of the collection chamber 5a is cooled by the flow of a coolant such as cooling water, NH ₄ Cl is deposited on the fins 5b and the inner wall surface of the collection chamber 5a, thus
H ₄ Cl is collected by this trap 5.

Next, the work of cleaning the first trap 5 will be described with reference to FIG. First, the valves 51 and 52 of the first flow path and the valve 57 for supplying the refrigerant of the first trap 5 are closed, and the valves 61 and 62 of the second flow path are closed.
And the valve 67 for supplying the refrigerant of the second trap 5 is opened. As a result, the gas exhausted from the processing chamber 2 is
Of the NH ₄ C by the second trap 6.
l is collected.

After a few seconds, the valve 5 of the cleaning liquid supply pipe 7
3 is opened to supply the cleaning water into the first trap 5 and the exhaust pipe 50 (first flow path) between the valves 51 and 52 on both sides of the first trap 5 to fill the same. Then NH ₄ Cl was allowed sufficient time for example, about 1 minute to dissolve in water by closing the valve 53, by opening the valve 55 of the valve 54 and the N ₂ gas supply pipe 73 of the washing waste liquid pipe 72, N _{2 The} gas is pumped to the flow path including the trap 5 between the valves 51 and 52 to drain the cleaning water inside.

In this embodiment, the cleaning water is sprayed toward the valve element 51a of the valve 51 and the fins 51b of the trap 5, so that they can be effectively cleaned. Instead of closing the valve 54 and filling the cleaning water between the valves 51 and 52 and leaving it to stand, the valve 53 may be opened to allow the flow of water. Then the valve 54,
55 is closed and the valve 56 of the N ₂ gas exhaust pipe 74 is opened to evacuate the inside of the flow path including the trap 5 by a vacuum pump (not shown) of a low grade such as a water seal pump to reduce the pressure. And close valve 5 again.
Open 3 and do the same wash.

At the time of the third cleaning, the valves 54 and 55 are opened to discharge the cleaning water inside with N ₂ gas, and then the valve 54 is closed and the valve 56 is opened to ventilate the N ₂ gas into the flow path. While heating, the inside is heated to 120 ° C. by the heating means 37 and 38 to be dried. In this case N
An inert gas other than ₂ or a dry gas such as dry air may be used.

Thereafter, the valve 62 on the downstream side of the second trap 60 is closed, and, for example, one second later, the valve 52 on the downstream side of the first trap 50 is opened, and the downstream side of the valve 51 is evacuated by the dry pump 42. After drying, a few seconds later, the valve 62 is opened, and thus the cleaning inside the first trap 5 is completed. The valve 62 is closed for a moment only by the valve 52.
This is to suppress the impact applied to the turbo molecular pump 41 when the is opened. The same applies to the case of cleaning the second trap 6. Further, in the processing chamber 2, the TiN film adheres to the processing gas injection plate 25 and the mounting table 21 other than the wafer W, for example.
It is cleaned by supplying F ₃ gas.

According to the above-described embodiment, the traps 5 and 6 are provided in parallel, and when one of the traps is cleaned, the other trap is used. Therefore, the downtime of the apparatus can be prevented and the throughput is improved. To do. Moreover, by controlling the valve, the trap is disconnected from the exhaust system,
Cleaning, drying, and connection to the exhaust system can be automated, so that workers can attach and detach traps.
It is very convenient because no cleaning work is required.

Since the traps 5 and 6 are provided on the downstream side of the turbo molecular pump 41, the traps can be downsized, and the water in the traps 5 and 6 flows back into the processing chamber 2 for processing. There is no possibility of adversely affecting the above or causing corrosion in the processing chamber 2. That is, the turbo molecular pump 41
Since a large conductance is required on the upstream side of the turbo molecular pump 41, for example, an exhaust pipe having a pipe diameter of 4 to 8 inches must be used. Therefore, a trap having a size corresponding to the exhaust pipe must be used. On the downstream side, the conductance may be smaller than that on the upstream side. For example, since the exhaust pipe has a small diameter of about 1 to 2 inches, a small trap can be used. Since the turbo molecular pump 41 is heated by the heating means 36, it is possible to prevent a product such as NH ₄ Cl from adhering to the inside of the turbo molecular pump 41. In this case, exhaust pipe 3
The heating means of Nos. 1 and 33 and the heating means of the turbo molecular pump 41 may be separated.

In the above description, when the trap is provided on the downstream side of the turbo molecular pump 41, the trap is not necessarily in parallel, and for example, only one trap may be used. When parallelizing traps,
It may be provided on the upstream side of the turbo molecular pump 41, or three or more traps may be arranged in parallel. Further, the present invention is
Plasma CVD other than when performing film forming processing other than the iN film
It can also be applied to vacuum processing devices such as etching, ashing and the like.

[0032]

According to the inventions of claims 1, 2, and 3, the first
And the second trap are paralleled so that one can be washed while the other is in use.
It is possible to prevent downtime of the device. According to the inventions of claims 3 and 5, the cleaning operation can be automated without removing the trap from the exhaust system. Further, according to the inventions of claims 2 and 4, it is possible to reduce the size of the trap.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a sectional view showing a structure of a trap used in an embodiment of the present invention.

FIG. 3 is a process drawing showing a trap cleaning process according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram showing an exhaust system of a conventional vacuum processing apparatus.

[Explanation of symbols]

2 processing chamber 21 mounting table 22 processing gas supply part 31, 33 exhaust pipe 36, 37, 38 heating means 41 turbo molecular pump 42 dry pump 5 first trap 6 second trap 7, 8 cleaning liquid supply pipe 72, 82 Cleaning liquid drain pipe 73, 83 N ₂ gas supply pipe 74, 84 N ₂ gas exhaust pipe

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Kaichi Hayashi, 1238-2, Kitashitajo, Fujii-cho, Nirasaki-shi, Yamanashi, Tokyo Electron Yamanashi Co., Ltd. (72) Kenji Yamaguchi, 2381 Kitashitajo, Fujii-cho, Nirasaki-shi, Yamanashi Prefecture No. 1 Ter Engineering Co., Ltd. (72) Inventor, Toshiya Suzuki, 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (72) Inventor, Takuya Sakai, 1015, Kamikodanaka, Nakahara-ku, Kawasaki, Kanagawa Prefecture, Fujitsu Limited

Claims (5)

[Claims] 1. A vacuum processing apparatus having an airtight processing chamber for introducing a processing gas to perform vacuum processing on an object to be processed under a vacuum atmosphere, and an exhaust passage connected to the processing chamber, First installed in the exhaust passage and connected in parallel to each other
And a second flow path, and a first collection part and a second collection part which are respectively provided in the first flow path and the second flow path and collect the product exhausted from the processing chamber. And a valve provided upstream and downstream of each of the first collection part and the second collection part in the first flow path and the second flow path. A vacuum processing device. 2. An airtight processing chamber for introducing a processing gas to perform vacuum processing on an object to be processed in a vacuum atmosphere, an exhaust passage connected to the processing chamber, and a downstream of the exhaust passage. A first vacuum evacuation means and a second vacuum evacuation means having a larger evacuation capacity than the first vacuum evacuation means, which are provided in order from the side; A first flow path and a second flow path, which are provided in an exhaust path between the second vacuum exhaust means and are connected in parallel with each other, and are provided in the first flow path and the second flow path, respectively. A first collection part and a second collection part for collecting the product exhausted from the processing chamber, and a first collection part in the first flow path and the second flow path. Valves provided on each upstream and downstream sides of the second collection part, and on the first collection part and the second collection part The vacuum processing apparatus characterized by each inner surface of the exhaust passage and the second evacuation means side, comprising a heating means for heating to a temperature above the temperature at which the product is precipitated. 3. The first collection part and the second collection part are connected to a cooling means for precipitating a product and a collection chamber for cleaning the collected product with a cleaning liquid. A cleaning liquid supply path and a drainage path, and a dry gas supply path and an exhaust path connected to the collection chamber for drying the collection chamber with a dry gas. The vacuum processing apparatus according to 1 or 2. 4. An airtight processing chamber for introducing a processing gas to perform vacuum processing on an object to be processed in a vacuum atmosphere, an exhaust passage connected to the processing chamber, and a downstream of the exhaust passage. A first vacuum evacuation means and a second vacuum evacuation means having a larger evacuation capacity than the first vacuum evacuation means, which are provided in order from the side; A collection unit that is provided in the exhaust path between the second vacuum evacuation units and collects the product exhausted from the processing chamber, an exhaust path upstream of the collection unit, and a second vacuum. A vacuum processing apparatus comprising: a heating unit configured to heat each inner surface of the exhaust unit to a temperature equal to or higher than a temperature at which the product is deposited. 5. A vacuum processing apparatus having an airtight processing chamber for introducing a processing gas to vacuum-process an object in a vacuum atmosphere, and an exhaust passage connected to the processing chamber, A step of parallelizing a part of the exhaust passage to provide a first collecting portion and a second collecting portion in one and the other flow passages, respectively, and closing valves on both sides of the first collecting portion; Next, a step of supplying a cleaning liquid into the first collecting section to remove the precipitated product, and a step of supplying a dry gas into the first collecting section to dry the inside of the collecting section. Evacuating the processing chamber through the second collection unit while the valves on both sides of the first collection unit are closed;
A method for operating a vacuum processing apparatus, comprising: