TWI240947B - Pumping system of load lock chamber and operating method thereof - Google Patents

Abstract

A pumping system of load lock chamber for pumping the gas in the load lock chamber, the system includes a rough pump, a first pumping line, a first isolation valve, a second pumping line, a second isolation valve, and an airflow regulator. Wherein the two ends of the first pumping line are connected to the load lock chamber and the rough pump respectively, the first isolation valve is disposed on the first pumping line, the second pumping line is disposed on the first pumping line beside the first isolation valve, the second isolation valve is disposed on the second pumping line, and the airflow regulator is disposed on the second pumping line.

Description

1240947 V. Description of the invention (1) The technical field to which the invention belongs The present invention relates to a vacuum system for a semiconductor process, and particularly to pumping of a load lock chamber System and method of operation. Prior technology ^ In the semiconductor manufacturing process, there are many processes that must be performed in a step-down or gl / w discharge environment, such as epitaxial growth, chemical vapor deposition (CVD, atmospheric pressure). Except for chemical vapor deposition (APCVD), etch, ng, physical vapor deposition (including vapor bonding, sputtering spatula), ion implantation (ion implantation) and so on. Therefore, a vacuum system must be installed in the machine engaged in the above process. Generally speaking, a load is usually installed in a vacuum system, and a 10ad lock chamber is used to maintain a vacuum in the process chamber to reduce pollution and shorten the process cycle. One side of the loading chamber is connected to the process chamber of the process to be operated, and the loading chamber is connected to a rough pump by a separate front line (fore Hne) ^ ⑽ 忌] pump ). During the manufacturing process, first the wafer is placed in the loading chamber, and then the air in the loading chamber is drawn out by a rough pump, so that the loading chamber starts to depressurize from atmospheric pressure (Utmosphere, ATM). When the loading chamber reaches a certain vacuum, it is opened. Valves that connect the loading chamber to the process chamber to send wafers to the process chamber 'and then proceed to subsequent processes. Please refer to Fig. 1. Fig. 1 shows a schematic diagram of a conventional suction system connected to a loading chamber. The extraction system includes at least a rough extraction pump 102, an extraction line 104, and an isolation valve "^. Both ends of the extraction line 104

10245pif.ptd Page 5 1240947 V. Description of the invention (2) It is separately connected to the loading chamber 1 00 and the rough suction pump 1 102 so that the gas in the loading chamber 1 00 can be discharged through the suction line 1 04 Withdraw. And the isolation valve 106 is arranged on the suction line 104, and is used to control the opening and closing of the suction line 104. When the pumping process is performed, the wafer (not shown) is first loaded to 100, then the isolation valve 1 〇β is opened, and the load is pulled out by the rough suction pump 1 〇2 through the pumping official road 104. The air in the chamber 100, so that the loading chamber begins to depressurize from atmospheric pressure (ATM). When the loading chamber 10 () reaches a certain vacuum, the connection between the loading chamber 100 and the process chamber (not shown) is opened. The valve is used to send the wafer to the process chamber, and then the subsequent process. J. In the above step of extracting the air in the loading chamber by the rough pump and / or any control of the suction speed, that is, when the pump is started and the suction is set, the rough The pumping speed provided by the pump is used for pumping. During the initial (1 η 1 γ a 1) stage where the loading chamber is depressurized from atmospheric pressure, this excessively fast pumping speed will cause air turbulent in the loading chamber, which will cause particles The problem. And, as the process line width gradually decreases, this particle problem will become more serious. On the other hand, if a rough pump with a lower suction rate is used to avoid the problem of turbulence, the throughput will be reduced. SUMMARY OF THE INVENTION Therefore, the object of the present invention is to provide a suction system of a loading chamber and a method for operating the same, which can avoid generating turbulence in the loading chamber during the pumping process and causing particle problems. Another object of the present invention is to provide a suction system of a loading chamber and

1240947 V. Description of the invention (3) The operation method can use a faster pumping rate for pumping to ensure that the yield of the semiconductor process does not decrease. The present invention proposes a gas extraction system of a loading chamber. The system is composed of at least a thick pipeline, a first isolation valve, and a second extraction pipe system. The extraction pump is suitable for extraction installation, a first extraction Composed of air and an air flow regulator. The first system is connected to the loading chamber and the rough suction pump, the first air-extraction pipeline, the second air-exhaust pipeline are arranged on the first air-exhaust pipeline, and the second isolation valve is disposed on the second air flow regulator system and disposed on the second Extraction pipe The present invention proposes a pumping system of the loading chamber for pumping the gas in the loading chamber. This method (low-speed pumping rate) starts pumping, and then reaches a second pumping rate (high-speed pumping rate). Intake and extraction rate is greater than the first extraction rate, and the first time is greater than the time to extract at the first extraction rate. Also, in the extraction system, the rough extraction path, the first isolation valve, and the second extraction line are used. When the first volume regulator is constructed, the first isolation valve of the pumping system is closed, then the second isolation valve is opened and then the first pumping rate of the rough pump is started to pump, and the first The first isolation valve is opened at one or two pumping rates so that the pumping rate continues. Evacuation valve second pump. The air pipe is equipped with an isolation valve. Two ends of the two isolation valve circuits are placed on the first two ends of the circuit, and a unified operation method. The pumping rate is switched between the second rate and the second rate. The first method of pumping air, the air speed pump, and the first and second isolation valve are the air flow rate, so that the pumping rate and the air flow of the pumping system and the air flow are the first to maintain the regulator and the system to switch to the first and second. Pump

10245pif.ptd Page 7 1240947 V. Description of the invention (4) As can be seen from the above, since the pumping system of the present invention is based on a pumping pipe for pumping at a high-speed pumping rate, a small pipe diameter is additionally installed. In the initial stage of starting the pumping, the pumped gas flows through the pumped pipe with a smaller diameter, and the pumped pipe with a smaller diameter and an air flow regulator arranged thereon The air flow / exhaust rate is well controlled, so it can be adjusted to a lower exhaust rate for the initial exhaust, and can avoid turbulence in the loading chamber, and then avoid the turbulence caused by the turbulence. The problem of particle contamination. 'Moreover, because the first pumping rate (low-speed pumping) operated to avoid turbulence is not long, and the second pumping rate (high-speed pumping) is maintained for the rest of the pumping step Therefore, as a whole, it is possible to maintain the high-speed pumping rate for pumping, thereby maintaining the productivity. It is even possible to use a rough pump with a higher pumping rate in conjunction with the low-speed pumping operation described above to further increase the yield while avoiding particle contamination caused by turbulence. In order to make the above-mentioned objects, features, and advantages of the present invention more comprehensible, a preferred embodiment is given below and described in detail with the accompanying drawings as follows: Embodiment 2 FIG. A schematic diagram of a preferred embodiment of an extraction system connected to a loading chamber. Please refer to FIG. 2. The air extraction system of this embodiment is suitable for extracting air in the loading chamber 200, and includes at least a rough extraction pump 202, a pumping line 204, and an isolation valve. 206, extraction line 208, extraction line isolation valve

10245pif.ptd Page 8 1240947 V. Description of the invention (5) 210 and air flow regulator (311 ^ 1 (^ 『6 £ 11131: 〇1 ') 212. The two ends of the exhaust pipe 2 0 4 are individually connected to Loading chamber 2000 and rough suction pump 202 'so that the gas in the loading chamber 2000 can be extracted through the suction pipe 204, and the diameter of the pipe used for the suction pipe 204 is, for example, general industrial The size used above is from 4 inches to 6 inches and 11 inches. The extraction line isolation valve 2 06 is arranged on the extraction line 2 04. With the opening and closing of the extraction line isolation valve 2 06, It is used to control whether the gas is exhausted through the exhaust pipe 0. The exhaust line isolation valve 2 0 is, for example, a pneumatic valve.

The two end points 2 1 4 and 2 1 6 of the exhaust line 2 0 8 are individually configured for exhaust; the I line isolation valve 2 0 6 is on the exhaust lines 2 0 4 on both sides, of which the end point 214 is equipped. The exhaust pipe between the loading chamber 2 0 0 and the extraction line isolation valve 2 06 is located on the road 2 0 0 and the end point 2 1 6 is arranged at the extraction line isolation valve 2 0 6 and the rough extraction pump 2 〇 丨On the suction line 204 between them, the gas can also be diverted from the end point 214 near the 200 side of the loading chamber through the suction line 208, and then merged at the end point 216 near the rough extraction 202 / then. The gas is exhausted to the exhaust pipe 204, and the size of the pipe diameter used in the inch path 208 is smaller than the official diameter size used in the exhaust pipe 204, which is, for example, about 1 inch. The extraction line isolation valve 2 0 is arranged on the extraction line 208.

The Li pipe Λ is opened and closed from the valve 210 to control whether the gas flows through the suction pipe 08. The exhaust line isolation valve 21 is a pneumatic valve, for example. The king gas flow regulator 212 is arranged on the exhaust pipe 208, and is used to adjust the gas flow through the exhaust pipe 208. Among them, the regulator 2 1 2 in the air machine can be arbitrarily arranged in the exhaust line isolation valve 2 i 〇 and

l〇245pi f.ptd Page 9 1240947 V. Description of the invention (6) The exhaust line 2 08 between the end points 2 1 6 or the end valve 2 1 4 and the exhaust line isolation valve 2 1 0 Between the exhaust pipe 2 0 8 and the air flow regulator 2 1 2 can use a throttle valve (t hr 111 111 eva 1 ve), for example, the use of a throttle valve can be used by Adjust the position of the throttle (the number of adjustable segments is, for example, 30 segments, from 0 to 30, from closed to fully open), and then adjust the air flow. The rough extraction pump 202 is connected to the extraction line 204, and is used to provide a driving force for extraction to extract the gas in the loading chamber 200 through the extraction line 204 or the extraction line 208. The rough pump 2 0 2 is, for example, a mechanical pump.

In addition, according to the actual process equipment, the loading chamber 2000 can be connected to a process chamber (not shown) corresponding to the process, so that the wafer can be depressurized or loaded in the loading chamber 2000. After the evacuation step, it is further sent to the process chamber for subsequent processes. Please continue to refer to FIG. 2. The operation method of the suction system of the loading chamber according to the preferred embodiment of the present invention is as follows. In the initial state, the isolation valves 206, 2 10 and the air flow regulator 2 1 2 are closed. Then open the air flow regulator 2 1 2 to the required flow rate (number of segments) and open the isolation valve 2 1 0. Then, start the rough pump 2 0 2 to start the extraction process. At this time, the loading chamber 2 0 The gas system in 0 is connected to the loading chamber 2 0 0 and the end point 2 1 4 through the extraction line 2 0 4, the end point 2 1 4, the extraction line 2 0 8, the end point 216 and the end point 216 and the connection between the rough The suction line 2 0 between the suction pumps 202 is drawn by the rough suction pump 202. Which opens the air flow regulator 2 j 2

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1240947 V. Description of the invention (7) To start the pumping step, for example, the air flow regulator 2 1 2 can be slowly opened to a certain flow size (number of segments) so that it reaches a certain pressure. Because in the extraction system of the present invention, the diameter of the extraction pipe 2 0 8 used is smaller than the diameter of the extraction pipe 2 0 4 and can be controlled by the air flow regulator 2 1 2 The air flow rate / exhaust rate of the room 2000 exhaust is well controlled, so the system can extract air at a lower air flow rate / exhaust rate, thereby avoiding being in the process room 200 at the beginning of the exhaust process The problem of spoiling.

Then, after a certain pressure is reached, for example, when the air pressure in the loading chamber 200 starts to be less than 300 Torr, the air flow regulator 21 2 is fully opened, and then the exhaust line isolation valve 2 06 is opened. At this time, the pumping step through the pumping line 204 will replace the pumping step through the pumping line 208, and the same high-speed pumping process as the conventional one will be performed. After the purpose of avoiding turbulence is achieved in the foregoing steps, all the isolation valves are opened, so that the extraction speed is switched from low-speed extraction to high-speed extraction to complete the extraction process, and because the high-speed time is low The high-speed pumping is long, and after the high-speed pumping, the high-speed pumping is maintained to the end of the pumping step. Therefore, as a whole, this pumping step is able to avoid the occurrence of turbulence and make the pumping step Maintain high-speed pumping rate, so that the yield will not be reduced. In the above-mentioned preferred embodiments, the gas in the loading chamber is extracted for depressurization or evacuation for illustration. However, the air extraction system and operation method of the present invention are not limited to this, and can also be applied to, for example, Process room

10245pif.ptd Page 11 124094 Know five. Description of the invention (8) and any other need to sum up the above-mentioned rate of extraction air extraction pipeline, the smaller the diameter of the air placed on it is well controlled, the initial extraction Qi is free from disturbance and is not long and is in a pumping state, so the overall Qi can be more coarse and avoid the rate of disturbance. Although this hair is used to limit the spirit and scope of the hair, The protection range needs to be reduced in pressure. Because the pumping starts to adjust the flow rate of the pumping pipeline, it can produce particles. In terms of avoiding the gas step, it can maintain the particles produced by the pumping pump or pump the gas on the pipeline of the present invention. The controller can be adjusted to avoid disturbances caused by sub-pollution, and the remaining maintenance rate can not be matched with the pumping of the contaminated vacuum. In addition, it is clear that the time from the pipe to the loading of the interrogation flow is faster than the derating. A better practice shows that anyone familiar with this technique can be used as a special cavity attached to the application. The gas system is equipped with a smaller diameter outside the pumping system at a faster speed, so that the extracted gas flows through the smaller diameter of the suction pipe and the air flow rate / extraction rate is low. Turbulence is generated in the progress room, and the problem is avoided. The low-speed pumping time of the operation is maintained at the high-speed pumping speed for pumping down. It is even possible to use the operation of low-speed air extraction. In the following, to further improve the product disclosure as described above, but it is not an artist, without departing from the changes and retouching of the present invention, so the scope of the present invention shall prevail.

10245pif.ptd Page 12 1240947 Brief Description of Drawings Figure 1 shows a schematic diagram of a conventional suction system connected to a loading chamber. FIG. 2 is a schematic diagram of an extraction system connected to a loading chamber according to another preferred embodiment of the present invention. Description of diagrams: 1 00, 2 0 0: loading chamber 1 0 2, 2 0 2: rough pump 104, 108, 204: suction line 1 0 6, 2 0 6, 2 1 0: isolation valve 2 1 2: Air flow regulating valve 2 1 4, 2 1 6: End point

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Claims (1)

1240947 _Case No. 92113564_Amendment of the month of the year _ 6. The patent application scope valve is arranged on the first suction line, a second suction line, the first suction line is arranged at both ends of the first isolation valve. A second isolation valve is disposed on the second suction pipe, an air flow regulator is disposed on the second suction pipe, and the air flow regulator makes the second suction pipe to the gas An extraction rate is less than the second extraction rate of the gas by the first extraction line. The method includes: maintaining the first isolation valve in a closed state, and opening the air flow regulator to a certain flow rate so as to pass The air flow rate of the air flow regulator is a certain value, and the second isolation valve is opened; the rough pump is started so that the extraction system performs air extraction at the first extraction rate; and the first isolation valve is opened To switch the pumping system from the first pumping rate to the second pumping rate and continue pumping, wherein the second pumping rate is greater than the first pumping rate and the second pumping rate Rate of evacuation time Greater than the time for pumping at the first pumping rate. 8. The method of operating the extraction system of the loading chamber as described in item 7 of the scope of the patent application, wherein when the pressure in the loading chamber is less than 300 torr, the first extraction rate is switched to the second extraction rate. 9. The operating method of the suction system of the loading chamber according to item 7 of the scope of the patent application, wherein the diameter of the first suction pipe is larger than the diameter of the second suction pipe. 10 · The operation method of the suction system of the loading chamber according to item 7 in the scope of the patent application, wherein the rough pump includes a mechanical pump. 1 1. The exhaust system of the loading chamber as described in item 7 of the scope of the patent application 10245twf1.ptc Page 15 1240947 _Case No. 92113564_ Year Month Amendment_ VI. Patent Application Scope Operation method, wherein the first isolation valve includes a pneumatic valve. 1 2 · The method of operating the suction system of the loading chamber as described in item 7 of the patent application scope, wherein the second isolation valve includes a pneumatic valve. 1 3. The method for operating the air extraction system of the loading chamber as described in item 7 of the patent application scope, wherein the air flow regulator includes a throttle valve. 10245twfl.ptc Page 16