TWI230391B - Method and apparatus for regulating exhaust pressure in evacuation system of semiconductor process chamber - Google Patents

Abstract

In accordance with the present invention, an apparatus and a method for regulating exhaust pressure in an evacuation system of a semiconductor process chamber are provided. The method comprises steps of generating a first pressure in the semiconductor process chamber with the evacuation system, monitoring the first pressure to generate a first signal, determining a set point for the exhaust pressure responsive to the first signal, and regulating the exhaust pressure by a controller till reaching the set point. The key aspect of the present invention is to maintain the equilibrium of the chamber pressure and the exhaust pressure by implementing an exhaust controller to control the gas flow rate introduced into the evacuation system. In other words, when the chamber pressure is increased, the gas is introduced into the evacuation system at an increased flow rate. On the other hand, when the chamber pressure is decreased, the gas is introduced into the evacuation system at a decreased flow rate. The dynamic control over the gas introduced into the evacuation system advantageously increase the speed of response during the changes of chamber pressure, as well as active control of the chamber pressure in place of moving the throttle valve. Thus, by minimizing the movement of throttle valve, the chances of particulate contamination of the process are greatly reduced.

Description

Page 6 1230391 V. Description of the invention (2) The system includes a turbo pump (turb0 ρ · ρ) and a trot valve (throtUe valve) of the reaction chamber. A pressure controller is used to control the opening and closing of $ 22, and f controls the increase and decrease of the vacuum pumping of the reaction chamber by the turbo pump, to maintain the reaction chamber at the set pressure. However, with this = possible, the pressure in the reaction chamber cannot be controlled to the exhaust pressure in the vacuum system tube:. In this way, the particles that may cause gas backflow will be sent back to the reaction chamber, the reaction chamber wall or contaminated crystals: wood, electrical impurities, pass, pass, or component adhesion. Can cause dyeing wafers and accumulate one of the throttling. When the particulate gas is contaminated, the slurry-etching process is taken as an example. The reaction product is usually transferred to the vacuum system (and then discharged to the atmosphere. However, the internal surface (internal surface of the pump and valve)) Gas pressure disturbance phenomenon will cause contamination of particles and cause product defects. In addition, when the pressure on the valve surface and the pressure of the reaction chamber changes at the same time, it may flow back to the reaction chamber. Therefore, the process is under vacuum. Medium is a very by-product or emission. Vacuum systems usually have a loss of flow between them and are sent back as pollutants. It is also important to keep the flow valve active. It is important to keep the inside of the pipe wall of the washing system. Some by-products are balanced, and the reaction chamber's pollution and particulates will be generated by the pollution source of the chamber. The fixed and rapid discharge is therefore known from the previous technology described above, which provides a stable and effective exhaust to reduce the throttle valve's activity. Frequently, it is very necessary to achieve a device and method for improving product reliability and product yield.

1230391__ V. Description of the invention (3) 5-3 The purpose and summary of the invention The purpose of the system is to balance the installation and the additional air-conducting system. Adding air into the vacuum and changing this really, and providing a method to reduce the above-mentioned gas pressure. Into this true exhaust. That is, the air system of the body flow system can simultaneously adjust the pressure of the air system of the invention. When the air pressure of the present invention is increased, instead of adding gas, it replaces the key gas in the background and method of the semiconductor to reach the chamber. of. On the other hand, the flow rate of the valve is "large". The traditional reaction chamber is to use the flow to maintain the reverse pressure. When the reverse pressure is increased, it will reduce the amount of vacuum. When it should be room. The shortcomings of the reaction of the granular polluting body in the rapid return to the reaction chamber are as follows: the exhaust gas is controlled by the semiconductor power and the true pressure drop is exhausted; the dynamic response of the reaction pressure to the reaction pressure; the vacuum of the reaction chamber; When the pressure space is low, the pressure of the guide chamber is adjusted. Due to the possibility of the device and method of $ _ in this issue. The purpose of the present invention is to provide a device and method for reducing the frequency of movement of a throttle valve according to the present invention. The pressure of the present invention is to provide a stable and effective way to prevent the product from being caused by the backflow of pollutants.

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defect. 1230391 According to the purpose described above, in a preferred embodiment, a device for adjusting the exhaust pressure of a semiconductor reaction chamber includes at least a vacuum pump, a first pressure sensor, and a second force month: a controller. The vacuum pump has an exhaust end and a suction end. The air end is in communication with the semiconductor reaction chamber through a -throttle space, and = = a first pressure is generated and the pressure between the throttle valve and the suction end. The first pressure sensor is used to measure the first pressure and produce ^ 2. The second pressure sensor is used to detect the exhaust pressure of the throttle valve and generate a second signal. The controller adjusts the exhaust pressure of the throttle valve and the suction end of the vacuum pump according to No. ::, and the first pressure within is higher than the exhaust pressure. The device of the present invention further includes two ports, which are located at the suction end (or upstream) of the vacuum pump. The controller uses the flow rate control of the gas passing through the air inlets to reach the second to adjust the exhaust pressure. The invention also provides a method for adjusting the exhaust pressure of a semiconductor reaction chamber. The method of the present invention includes at least the following steps. A vacuum system is used to generate a first pressure in the semiconductor reaction chamber, and an exhaust pressure is generated between the semiconductor reaction chamber and the vacuum system. Then, a first pressure is detected and a first bluff is generated. The set value of the exhaust pressure is obtained according to the first signal, wherein the first pressure is higher than the set value of the exhaust pressure. After that, use the controller to adjust the exhaust pressure to its set value. The set value of the exhaust pressure can be stored in the exhaust controller in advance according to the pressure of the reaction chamber. That is, each reaction chamber pressure has a corresponding set value of exhaust pressure. The controller can be accessed through the air inlet

1230391-^ -_ V. Description of the invention (5) Gas flow control in vacuum system to adjust the exhaust pressure. The 5-4 invention is explained in detail: 贯; ^, +, ♦ months will be described in detail as follows. However, in addition to the detailed description, the present invention can also be widely implemented in other embodiments, and the scope of the present invention is not limited, which is subject to the scope of subsequent patents. In the preferred embodiment of the present invention, a device for adjusting the exhaust pressure of the semiconductor to Ϊf ί; is provided. Referring to the figure, in the normal manufacturing process, the wafer is placed in the support element of the reaction chamber 100. The reaction chamber 100 is kept in a vacuum state. Then, the gas supply is used for 2 and 2 1⑽Φ process conditions. The required flow rate is to pass the process gas into the vacuum system. The vacuum system 120 is used to generate and maintain the first normal state of the reaction. The vacuum system 120 includes at least a control valve 122, a pump 124, and a first air inlet. 126. No.-direct air pump 124

The Sit end control valve 122 is in communication with the reaction chamber 100. The control here is how to regulate the flow through the reaction chamber (100 ... throttle valve). The first person to identify the Un is the valve (, ^ ^ ^ ^ Ji Ka Shi is located downstream of the control valve 12: ¾ is located at the suction end 128 of the first vacuum pump 124. In addition, the vacuum system 1 2 0 can Enter more than one vacuum

Page 10 1230391 V. Description of the invention (6 ^ '" Pump and air inlet ^ The second vacuum pump 132 and the second air inlet 134 as shown in the first figure. And the exhaust end 13 of the first vacuum pump 124 ( ) Is in communication with the breast pumping end 136 ″ of the second vacuum pump 132. The first vacuum pump 124 may be a vacuum pump such as a turbo pump, and the second vacuum pump 132 is generally a rotary pump. Usually, the second vacuum pump is used first. The vacuum pump 132 draws the pressure of the reaction chamber 100 from the atmospheric pressure to a lower vacuum, and then when the low pressure limit of the second vacuum pump 132 is reached, the first vacuum pump 124 continues to pump down to lower the pressure. The two air inlets 3, 4 are located downstream (or the exhaust end 128) of the first vacuum pump, 24, or the suction end 136 of the second vacuum pump 132. A main focus of the present invention is in the exhaust system Maintain a smooth and flowing exhaust. In other words, the pressure in the exhaust system has a decreasing order in the different exhaust stages. Therefore, by-products generated during the process can be smoothly discharged from the reaction chamber through the vacuum system. That is, to reach the reaction chamber pressure The balance between the pressure and the exhaust pressure, the first exhaust pressure (P2) in the first exhaust phase of the first vacuum pump is lower than the reaction chamber pressure (pi), and the second exhaust phase in the second exhaust phase of the second vacuum pump The exhaust pressure (P3) is lower than the first exhaust pressure (P2), that is, the reaction chamber pressure is greater than the first exhaust pressure and greater than the second exhaust pressure (P1 > P2 > P3). In some applications of the prior art 'Extra gas (or bal last gas or purge gas, such as nitrogen) is introduced into the vacuum system through the air inlet between the vacuum system's pipelines to help respond quickly. Changes in chamber pressure, while expecting to replace the throttle

1230391 V. Description of the invention (7) The action adjusts the pressure in the reaction chamber. The method of using additional gas to control the pressure of the reaction chamber 'Although it is beneficial to reduce the position of the control valve, but because the additional gas is usually passed into the vacuum system at a fixed flow rate, when the pressure of the reaction chamber exceeds The range that can be controlled by a fixed flow of gas will cause pollution of the reaction chamber. Therefore, when the process gas flowing into the reaction chamber is increased, that is, when the pressure of the reaction chamber is increased, the fixed gas flow rate is obviously insufficient, and it is obvious that the flow rate is set too low to immediately respond to the increase in the pressure of the reaction chamber. 'And unable to maintain smooth exhaust. In this way, the exhaust may be caused too quickly, causing damage to the materials covering the interior of the reaction chamber, such as high molecules, resulting in contamination, and the yield is reduced due to product defects. Conversely, when the process gas flowing into the reaction chamber is reduced, that is, when the pressure in the reaction chamber is reduced, the fixed flow of gas is significantly excessive. Obviously, at this time, the flow rate is set too high to immediately respond to the pressure drop in the reaction chamber. This creates a spoiler phenomenon, and the pollutants in the vacuum system are backflowed back to the reaction chamber. Therefore, in order to solve the above-mentioned shortcomings of applying gas in addition to a fixed flow rate, another important point of the present invention is to use an additional exhaust controller 1 40 to control the gas flow rate added to the vacuum system 20 to adjust the vacuum ^ The exhaust pressure of the system 1 20 is reached to maintain the equilibrium between the reaction chamber pressure and the exhaust pressure. The use of the exhaust gas controller 14 can dynamically control the gas flow rate of the vacuum system through the air inlet according to the pressure of the reaction chamber, and avoid the lack caused by adding a fixed flow of gas. Referring again to the first figure, the first pressure sensor 150 is used to detect

1230391 V. Description of the invention (8) Response, pressure (P 1), and generate a first signal. The exhaust controller 4 adjusts the first exhaust pressure (p2) according to the first signal until the second pressure sensor 160 detects that the first exhaust pressure reaches a corresponding value, and this phase, The corresponding value is the key point of smooth forward exhaust (i.e. p 1 > P 2). The corresponding value of the first exhaust pressure can be stored in the exhaust controller 140 in advance according to the pressure of the reaction chamber. That is, each reaction chamber pressure has a value corresponding to the set value of the first exhaust pressure. In the present invention, the purpose of controlling the flow rate of the gas added to the vacuum system 12 through the first air inlet 12 is to achieve the purpose of adjusting the first exhaust pressure. In other words, when the process gas flow into the reaction chamber 10 () increases, the exhaust controller 丨 4 will dynamically increase the gas flow 17 into the vacuum system 12 according to the first signal, in ° Reach the balance between pressure and exhaust pressure. Conversely, when the process gas flow rate entering the reaction chamber 100 decreases, the exhaust gas controller 14 will dynamically reduce the gas flow rate 170 into the vacuum system 120 according to g number ^

Balance between reaction chamber pressure and exhaust pressure. ^ J-In addition, when using more than one pump in a vacuum system, " when not using two: combined pumps. The second pressure sensor 160 is at the detection level. The exhaust controller 140 also adjusts the second exhaust according to the first signal and the second signal, that is, the third pressure sensor 180 detects the second exhaust pressure (a value of 1 丨, the value corresponding to m is consistent with Shundaziying (ie P1 > P2 > P3). The present invention also controls the gas flow rate j 90 of the key vacuum system 120 through the row rolling, which is an inlet 134 added to the sheep and adjusts the second row Air pressure

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1230391

The purpose of force. Correction, the Ben Zhiming device may further include a processing device 2 0 0, such as a strip cleaner (s c r u b b e r), which is used to process the temporary μ + f shells discharged from the vacuum system 1 20. ^ ^ Due to the dynamic control of the gas flow into the vacuum system, the frequency of the throttle valve can be reduced. This reduces the amount of contaminated particles generated by the throttle. What must be explained here is that the gas introduced through the first air inlet and an air inlet can be directly passed into the first vacuum pump or the second vacuum pump, or near the upstream of the pump, so it is effective. Adjust the exhaust pressure (P2, p3) to reduce the movement of the throttle valve. Therefore, it is very effective to reduce the pollution chance of particles. In another embodiment, the present invention also provides a method for adjusting exhaust pressure in a vacuum system. The second figure is a flowchart of the method of adjusting the exhaust pressure. As shown in the second figure, the method of the present invention includes at least steps 2 10, 2 2 0, 2 3 0, and 2 4 0. First, as described in step 210, a vacuum system is used to generate a first pressure in the semiconductor reaction chamber, and an exhaust pressure is generated between the semiconductor reaction chamber and the vacuum system. As described in step 220, the first pressure or the pressure of the reaction chamber is detected, and a first signal is generated. In step 230, a set value of the second pressure is obtained according to the first signal, and the set value of the second pressure is smaller than the first pressure. Step 2 4 0 is an exhaust controller that adjusts the exhaust pressure of the vacuum system to a set value of the second pressure by controlling the flow of the pressure-stabilizing gas (b a 1 1 a s t g a s) into the vacuum system. The set value of the second pressure can be stored in the exhaust controller in advance according to the pressure of the reaction chamber. That is, each reaction chamber pressure has a corresponding set number of second pressures.

Page 14 1230391 V. Description of the invention (10) value. The exhaust controller controls the exhaust pressure of the vacuum system by controlling the opening and closing of the controllable valves that are connected to the vent of the vacuum system for the regulated gas. Due to the dynamic control of the gas flow to the vacuum system, the frequency of control valve activity can be reduced. This reduces the amount of contaminated particles generated by the throttle. The above is only a preferred embodiment of the present invention, and is not intended to limit the scope of patent application of the present invention. Any other equivalent changes or modifications made without departing from the spirit disclosed by the present invention shall be included in the following Within the scope of patent application.

Page 15 1230391__ Schematic illustration of the purpose, characteristics and advantages of the present invention can be clearly seen from the following detailed description and description of the drawings: the first diagram is a simplified diagram of the device for adjusting exhaust pressure of the present invention; and the second FIG. Is a flowchart of a method for adjusting exhaust pressure according to the present invention. Main symbols: I 0 0 Semiconductor reaction chamber II 0 Gas supply system 1 2 0 Vacuum system 1 2 2 Control valve 124 First vacuum pump 1 2 6 First air inlet 128 Intake end of first vacuum pump 1 3 0 Exhaust end of the first vacuum pump 132 Second vacuum pump 134 Second air inlet 1 3 6 Suction end of the second vacuum pump 1 3 8 Exhaust end of the second vacuum pump 140 Exhaust controller 1 50 0 First pressure sensor 1 6 0 second pressure sensor 170 gas (a)

Page 16 1230391 Simple illustration of the drawing 1 8 0 Third pressure sensor 1 9 0 Gas (2) 2 0 0 Processing device 2 1 0 Step block 1 2 2 0 Step block 2 2 3 0 Step block 3 2 4 0 Step Box four ί i

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Claims (1)

123 03 91 Case No. 90126967_ 生 _ ^ _ 0_MODIFY__ The second suction of the two vacuum pumps is in communication with the first exhaust end of the first vacuum pump. 4. If the device for adjusting exhaust pressure according to item 3 of the patent application scope, further includes a third pressure sensor for detecting a second exhaust pressure at the second suction end of the second vacuum pump and generating A third signal. 5. The device for adjusting exhaust pressure according to item 4 of the scope of patent application, wherein the controller adjusts the second row of the second suction end of the second vacuum pump according to the second signal and the third signal. Air pressure such that the first exhaust pressure is higher than the second exhaust pressure. ^ 6. The device for adjusting exhaust pressure according to item 3 of the scope of patent application, further comprising a second air inlet port located at the second suction end of the second vacuum pump. 7. The device for adjusting exhaust pressure according to item 6 of the scope of patent application, wherein the controller controls a second flow rate of a second gas passed through the second air inlet to adjust the second exhaust pressure. 8. The device for adjusting exhaust pressure according to item 1 of the scope of the patent application, wherein the vacuum chamber includes a reaction chamber. 9. A device for adjusting exhaust pressure, the device for adjusting exhaust pressure includes: Page 19 1230391 Case No. 90126967 Amendment VI. Patent application scope A vacuum pump has an exhaust end and an intake end, of which the intake end is connected to a vacuum chamber for generating a first in the vacuum chamber. Pressure; a throttle valve is located between the vacuum pump and the vacuum chamber, so that there is an exhaust pressure between the vacuum pump and the vacuum chamber; a first pressure sensor for detecting the first pressure and generating a first A signal; a second pressure sensor for detecting the exhaust pressure at the suction end of the vacuum pump; and a controller for adjusting the exhaust pressure at the suction end of the vacuum pump to reach a value based on the first signal A set value, wherein the first pressure is higher than the set value of the exhaust pressure. 10. The device for adjusting exhaust pressure according to item 9 of the scope of the patent application, further comprising a first air inlet port between the suction end of the vacuum pump and the throttle valve. 1 1. The device for adjusting exhaust pressure according to item 10 of the scope of patent application, wherein the controller controls a flow rate of a gas passed through the air inlet to adjust the exhaust pressure. 1 2. A method for adjusting exhaust pressure, including the following steps: using a vacuum device to generate a first pressure in a vacuum chamber, and an exhaust pressure in a space between the vacuum chamber and the vacuum device; detecting the first A pressure and a first signal; Page 20 1230391 Case No. 90126967 Amendment VI. Scope of patent application and get one set value of the exhaust pressure according to the first signal; Adjust the exhaust waste gas to reach the set value. 13. The method for adjusting exhaust pressure according to item 12 of the scope of patent application, wherein the set value of the exhaust pressure is lower than the first pressure. 14. The method for adjusting exhaust pressure according to item 12 of the scope of patent application, wherein the above-mentioned step of obtaining the set value of the exhaust pressure includes at least the selection of the corresponding first pressure stored in a controller in advance. The set value of the exhaust pressure. 15. The method for adjusting exhaust pressure according to item 12 of the scope of patent application, wherein the above-mentioned step of adjusting the exhaust pressure to the set value at least includes using a controller to control and add the vacuum device and the vacuum chamber. A flow of a gas in the space to adjust the exhaust pressure to the set value. Page 21