Pressure control system, pressure control method and voltage stabilization method

Abstract

This application provides a pressure control system, a pressure control method, and a pressure stabilization method for controlling the pressure of the thermally conductive medium on the back side of a wafer. The pressure control system includes: a pipeline, a control valve assembly, a pressure storage device, a vacuum device, and a controller. One end of the pipeline is connected to the inlet of the thermally conductive medium, and the other end is connected to an electrostatic adsorption plate. The control valve assembly is disposed in the pipeline. The pressure storage device is disposed in the pipeline and includes a pressure boosting state and a pressure stabilization state. In the pressure boosting state, the pressure storage device is used to pressurize the thermally conductive medium; in the pressure stabilization state, the pressure storage device is used to buffer and store the thermally conductive medium. The vacuum device is connected to the pipeline. The controller is connected to the control valve assembly and the vacuum device, and the controller is used to control the intake and discharge of the thermally conductive medium through the control valve assembly. This application solves the problems of existing methods where the pressure of the thermally conductive medium on the back side of a wafer is difficult to maintain stable, resulting in severe loss of the thermally conductive medium and difficulty in increasing the pressure of the thermally conductive medium on the back side of the wafer.

Description

Technical Field

[0001] This application relates to semiconductor pressure control systems, and more particularly to pressure control systems, pressure control methods, and pressure stabilization methods. Background Technology

[0002] In semiconductor manufacturing etching equipment, wafers are typically placed on electrostatic precipitators (ESCs) within a vacuum chamber. During wafer processing, plasma within the chamber continuously bombards the wafer surface, causing its temperature to rise. Since the wafer surface needs to be stabilized at a set temperature, heat dissipation is necessary. Heat dissipation primarily occurs through heat conduction between the wafer and the ESCs. Because a vacuum gap exists between the wafer and the ESCs, and vacuum has low thermal conductivity, a heat-conducting medium (such as helium) with good thermal conductivity can be introduced between the back of the wafer and the ESCs to improve the heat transfer efficiency.

[0003] The higher the pressure of the back-side thermal interface material (TIM) on the wafer, the more TIM molecules are present on the wafer's back side, resulting in higher thermal conductivity. Conversely, the lower the TIM pressure, the fewer TIM molecules are present, leading to lower thermal conductivity. To ensure stable thermal conductivity, the TIM pressure on the wafer's back side needs to be maintained. Existing systems for supplying TIM on the wafer's back side utilize pressure control valves and dry pumps for pressure stabilization. When the TIM pressure is insufficient, the pressure control valve opens wider to replenish the TIM. When the TIM pressure is excessive, the dry pump removes the excess TIM. However, excessively high TIM pressure results in direct loss of the excess TIM due to its direct removal by the dry pump.

[0004] Because the supply pressure of the thermally conductive medium (usually provided by the plant) is unstable, it tends to be excessively high multiple times during wafer fabrication. This leads to repeated over-pressure of the thermally conductive medium on the back side of the wafer, causing the dry pump to repeatedly start and remove the medium, resulting in significant loss of thermally conductive medium. Furthermore, the higher the supply pressure, the higher the pressure of the thermally conductive medium on the back side of the wafer. This means the dry pump will spend more time removing excess medium, resulting in a loss of machine productivity (WPH) and further loss of thermally conductive medium. Currently, the supply pressure of the thermally conductive medium is fixed (i.e., fluctuates widely within a fixed pressure value). The system supplying the thermally conductive medium to the back side of the wafer cannot boost its pressure, making it difficult to achieve high pressures. Therefore, existing technologies suffer from the problems of unstable back-side thermally conductive medium pressure leading to significant loss of thermally conductive medium and difficulty in increasing the back-side thermally conductive medium pressure. Summary of the Invention

[0005] To address the problems in existing technologies, such as the difficulty in maintaining stable pressure of the thermally conductive medium on the back side of the wafer, leading to significant thermally conductive medium loss and difficulty in increasing the pressure, this application provides a pressure control system for controlling the pressure of the thermally conductive medium on the back side of the wafer. The pressure control system includes: a pipeline, a control valve assembly, a pressure storage device, a vacuum device, and a controller. One end of the pipeline is connected to the inlet of the thermally conductive medium, and the other end is connected to an electrostatic adsorption disk. The control valve assembly is disposed in the pipeline. The pressure storage device is disposed in the pipeline and includes a pressure boosting state and a pressure stabilizing state. In the pressure boosting state, the pressure storage device is used to pressurize the thermally conductive medium; in the pressure stabilizing state, the pressure storage device is used to buffer and store the thermally conductive medium. The vacuum device is connected to the pipeline. The controller is connected to the control valve assembly and the vacuum device. The controller generates control commands, and the control valve assembly opens and closes based on the control commands to control the entry and / or discharge of the thermally conductive medium into and / or out of the pressure storage device.

[0006] Preferably, the electrostatic adsorption disk includes an edge region and a central region, the pipeline includes a first pipeline and a second pipeline, the first pipeline is connected to the edge region, the inlet end of the heat-conducting medium and the air extraction device, and the second pipeline is connected to the central region, the inlet end of the heat-conducting medium and the air extraction device.

[0007] Preferably, the pressure storage device includes a first pressure storage tank and a second pressure storage tank, the control valve group includes a first control valve group and a second control valve group, the first pressure storage tank and the first control valve group are disposed in the first pipeline, the second pressure storage tank and the second control valve group are disposed in the second pipeline, and the controller is connected to the first control valve group and the second control valve group.

[0008] Preferably, the first control valve group includes a first control master valve, and the first pipeline is connected to the inlet end of the heat transfer medium through the first control master valve. The second control valve group includes a second control master valve, and the second pipeline is connected to the inlet end of the heat transfer medium through the second control master valve. The controller is connected to the first control master valve and the second control master valve.

[0009] Preferably, the first pipeline includes a first branch, a second branch, and a first connecting pipe. The first branch and the second branch are connected in parallel. One end of the first branch and the second branch connected in parallel is connected to the first control main valve, and the other end of the first branch and the second branch connected in parallel is connected to the air extraction device. The first pressure tank is disposed on the first branch, and the first branch and the second branch are connected to the edge area through the first connecting pipe.

[0010] Preferably, the first control valve group further includes a first control valve, a second control valve, a third control valve, a fourth control valve, a fifth control valve, and a first pressure stabilizing device. The first control valve, the second control valve, the third control valve, the fourth control valve, the fifth control valve, the first pressure stabilizing device, and the controller are connected. The first control valve, the second control valve, and the third control valve are sequentially arranged in the first branch, and the fourth control valve, the fifth control valve, and the first pressure stabilizing device are sequentially arranged in the second branch. The first pressure tank is arranged between the first control valve and the second control valve. The connection point of the first connecting pipe to the first branch is arranged between the second control valve and the third control valve, and the connection point of the first connecting pipe to the second branch is arranged between the fourth control valve and the fifth control valve.

[0011] Preferably, the second pipeline includes a third branch, a fourth branch, and a second connecting pipe. The third branch and the fourth branch are connected in parallel. One end of the third branch and the fourth branch connected in parallel is connected to the second control main valve, and the other end of the third branch and the fourth branch connected in parallel is connected to the air extraction device. The second pressure tank is located on the third branch, and the third branch and the fourth branch are connected to the central area through the second connecting pipe.

[0012] Preferably, the second control valve group further includes a sixth control valve, a seventh control valve, an eighth control valve, a ninth control valve, a tenth control valve, and a second pressure stabilizing device. The sixth control valve, the seventh control valve, the eighth control valve, the ninth control valve, the tenth control valve, and the second pressure stabilizing device are connected to the controller. The sixth control valve, the seventh control valve, and the eighth control valve are sequentially arranged in the third branch, and the ninth control valve, the tenth control valve, and the second pressure stabilizing device are sequentially arranged in the fourth branch. The second pressure tank is arranged between the sixth control valve and the seventh control valve. The connection point of the second connecting pipe to the third branch is arranged between the seventh control valve and the eighth control valve, and the connection point of the second connecting pipe to the fourth branch is arranged between the ninth control valve and the tenth control valve.

[0013] This application also provides a pressure control method applied to the pressure control system, comprising the following steps:

[0014] Control the transfer of the wafer to the electrostatic adsorption disk;

[0015] The first control valve and the sixth control valve are opened, and the second control valve and the seventh control valve are closed, so that the heat transfer medium enters the first pressure tank through the first control main valve until the pressure of the first pressure tank reaches a first predetermined pressure value, and the heat transfer medium enters the second pressure tank through the second control main valve until the pressure of the second pressure tank reaches a second predetermined pressure value;

[0016] Controlling the wafer to be positioned on the electrostatic adsorption disk; and

[0017] The first control valve and the sixth control valve are closed, and the second control valve and the seventh control valve are opened, so that the heat-conducting medium in the first pressure tank and the second pressure tank can enter the electrostatic adsorption plate.

[0018] This application also provides a voltage stabilization method applied to the voltage control system, comprising the following steps:

[0019] The first control valve and the sixth control valve are closed to disconnect the pipeline between the first control main valve and the first pressure tank, and to disconnect the pipeline between the second control main valve and the second pressure tank;

[0020] The second control valve and the seventh control valve are opened to connect the first pressure tank and the edge region, and to connect the second pressure tank and the center region.

[0021] The fourth and ninth control valves are opened to connect the first main control valve to the edge region and the second main control valve to the center region.

[0022] Control the third control valve and the eighth control valve to close, thereby disconnecting the pipeline between the connection point of the first connecting pipe and the first branch and the air extraction device, and disconnecting the pipeline between the connection point of the second connecting pipe and the third branch and the air extraction device; and

[0023] The fifth control valve, the first pressure stabilizing device, the tenth control valve, the second pressure stabilizing device, and the air extraction device are opened to allow the edge region to connect with the air extraction device via the first connecting pipe and the second branch, and to allow the central region to connect with the air extraction device via the second connecting pipe and the fourth branch.

[0024] The beneficial effects of this application are as follows: By installing a control valve assembly and a pressure storage device in the pipeline, one end of the pipeline is connected to the inlet of the heat transfer medium, the other end is connected to the electrostatic adsorption plate, and the pipeline is simultaneously connected to the extraction device. The controller controls the opening and closing of the control valve assembly to control the entry and / or discharge of the heat transfer medium into and / or from the pressure storage device. Since the pressure storage device has two states: a pressure-boosting state and a pressure-stabilizing state, when the pressure storage device is in the pressure-boosting state, it can boost the pressure of the heat transfer medium to a predetermined pressure value. When the electrostatic adsorption plate requires heat transfer medium at the predetermined pressure value, simply connecting the pressure storage device and the electrostatic adsorption plate is sufficient. Compared to the existing method of obtaining heat transfer medium from the plant, directly using the pressure storage device for pressure boosting can achieve a higher heat transfer medium pressure. When the pressure storage device is in the pressure-stabilizing state, it can buffer and store the heat transfer medium, keeping the pressure of the heat transfer medium in the pipeline stable, thereby keeping the pressure of the heat transfer medium in the electrostatic adsorption plate connected to the pipeline stable. This prevents severe loss of heat transfer medium due to repeated starts of the extraction device caused by unstable heat transfer medium pressure.

[0025] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, the following describes the application in detail with reference to the preferred embodiments and accompanying drawings. Attached Figure Description

[0026] Figure 1 This is a circuit diagram of the pressure control system in an embodiment of this application;

[0027] Figure 2 This is a block diagram of the control valve assembly, controller, and air extraction device in the embodiments of this application;

[0028] Figure 3 This is a block diagram of the first control valve group and the controller in an embodiment of this application;

[0029] Figure 4 This is a block diagram of the second control valve group and the controller in an embodiment of this application;

[0030] Figure 5 This is a circuit diagram of the pressure control system (pressure storage device in pressure boosting state) in an embodiment of this application;

[0031] Figure 6 This is a flowchart of the pressure control method of the pressure control system in the embodiments of this application;

[0032] Figure 7 This is a circuit diagram of the pressure control system in this embodiment (the pressure storage device is connected to the electrostatic adsorption plate after being pressurized);

[0033] Figure 8 This is a comparison diagram of the pressure control effect of the pressure control system and the traditional pressure control system in the embodiments of this application;

[0034] Figure 9 This is a flowchart of the voltage stabilization method of the voltage control system in the embodiments of this application;

[0035] Figure 10 This is a circuit diagram of the pressure control system in the embodiments of this application (the pressure storage device is in a stable pressure state).

[0036] In the attached figures, the following labels are used:

[0037] 1. Pressure control system

[0038] 10 Piping

[0039] 100 First Pipeline

[0040] 1000 First Branch Road

[0041] 1001 Second Branch Road

[0042] 1002 First connecting pipe

[0043] 101 Second Pipeline

[0044] 1010 Third Branch Road

[0045] 1011 Fourth Branch Road

[0046] 1012 Second connecting pipe

[0047] 11 Control valve assembly

[0048] 110 First control valve group

[0049] 1100 First control main valve

[0050] 1101 First control valve

[0051] 1102 Second control valve

[0052] 1103 Third control valve

[0053] 1104 Fourth Control Valve

[0054] 1105 Fifth Control Valve

[0055] 1106 First voltage stabilizer

[0056] 111 Second control valve group

[0057] 1110 Second control main valve

[0058] 1111 Sixth Control Valve

[0059] 1112 Seventh Control Valve

[0060] 1113 Eighth Control Valve

[0061] 1114 Ninth Control Valve

[0062] 1115 Tenth Control Valve

[0063] 1116 Second voltage stabilizer

[0064] 12 Pressure Storage Device

[0065] 120 First Pressure Storage Tank

[0066] 121 Second Pressure Storage Tank

[0067] 13. Air extraction device

[0068] 14 Controller

[0069] 2 wafers

[0070] 3. Heat transfer medium inlet end

[0071] 4. Electrostatic adsorption tray

[0072] 40 Edge Area

[0073] 41 Central Area

[0074] Pressure control method steps: S11-S14

[0075] Voltage stabilization method steps: S21-S25 Detailed Implementation

[0076] The following specific embodiments illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification.

[0077] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present application will now be described in detail with reference to the accompanying drawings and embodiments. To enable those skilled in the art to better understand the solutions of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0078] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products, or devices.

[0079] It should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0080] Please also refer to Figure 1 and Figure 2 In one embodiment, a pressure control system 1 is provided for controlling the pressure of the thermally conductive medium on the back side of a wafer 2. The pressure control system 1 includes: a pipeline 10, a control valve assembly 11, a pressure storage device 12, a vacuum device 13, and a controller 14. One end of the pipeline 10 is connected to the thermally conductive medium inlet 3, and the other end of the pipeline 10 is connected to an electrostatic adsorption disk 4. For example, the pipeline 10 can be a metal pipe, and the thermally conductive medium can be a gas with good thermal conductivity, such as helium. The thermally conductive medium inlet 3 can be a terminal, which is used to provide the thermally conductive medium. The control valve assembly 11 is disposed on the pipeline 10. The wafer 2 is disposed on the upper surface of the electrostatic adsorption disk 4.

[0081] Please also refer to Figure 1 and Figure 2 For example, the control valve assembly 11 can be a combination of multiple gas pipeline valves, pneumatic valves, or solenoid valves. The control valve assembly 11 can be provided with an inlet and an outlet. The inlet and outlet of the control valve assembly 11 are respectively connected to the pipeline 10 (for example, the inlet and outlet of the control valve assembly 11 are provided with external threads, and the pipeline 10 is provided with internal threads. The two are connected by threads. The specific control valves and pressure storage devices 12 of the control valve assembly 11 described below can be connected in a similar way). The heat transfer medium in the pipeline 10 enters from the inlet of the control valve assembly 11 and exits from the outlet of the control valve assembly 11.

[0082] Please refer to Figure 1The pressure storage device 12 is installed in the pipeline 10. The pressure storage device 12 includes a pressurization state and a pressure stabilization state. In the pressurization state, the pressure storage device 12 is used to pressurize the heat transfer medium. In the pressure stabilization state, the pressure storage device 12 is used to buffer and store the heat transfer medium. The pressure storage device 12 may include, but is not limited to, a pressure storage cylinder. For example, in the pressurization state, a one-way valve can be built into the pressure storage device 12, which is connected to the control valve group 11. The heat transfer medium is provided by the heat transfer medium inlet 3. By controlling the opening and closing of the control valve group 11, the heat transfer medium can only enter the pressure storage device 12 through the one-way valve until the pressure of the heat transfer medium in the pressure storage device 12 rises to a predetermined pressure value. During this process, the pressure storage device 12 is temporarily not connected to the electrostatic adsorption plate 2, nor does it provide heat transfer medium to the outside.

[0083] Please also refer to Figure 1 and Figure 2 In the stabilizing state, the heat transfer medium can normally enter and exit the pressure storage device 12. The pressure stabilizing device in the pressure storage device 12 (e.g., if the pressure storage device 12 is a pressure storage cylinder, the pressure stabilizing device can be an air bladder) completes the buffering and storage of the heat transfer medium. The vacuum device 13 is connected to the pipeline 10. For example, the vacuum device 13 can be a dry pump, used to remove excess heat transfer medium from the pipeline 10. The controller 14 is connected to the control valve group 11 and the vacuum device 13. The controller 14 is used to generate control commands, and the control valve group 11 opens and closes based on the control commands to control the entry and / or exit of the heat transfer medium into and / or out of the pressure storage device 12. For example, the controller 14 can be an industrial computer or a microcontroller, and the controller 14, control valve group 11, and vacuum device 13 can be electrically connected via cables.

[0084] By installing a control valve assembly 11 and a pressure storage device 12 on pipeline 10, one end of pipeline 10 is connected to the heat transfer medium inlet 3, the other end of pipeline 10 is connected to the electrostatic adsorption plate 4, and pipeline 10 is simultaneously connected to the air extraction device 13. The controller 14 controls the opening and closing of the control valve assembly 11 to control the entry and / or discharge of the heat transfer medium into and / or out of the pressure storage device 12. Since the pressure storage device 12 has two states: a pressure boosting state and a pressure stabilizing state, when the pressure storage device 12 is in the pressure boosting state, it can boost the pressure of the heat transfer medium to a predetermined pressure value. When the electrostatic adsorption plate 4 requires heat transfer medium at a predetermined pressure value, simply connect the pressure storage device 12 and the electrostatic adsorption plate 4. Compared to directly obtaining the heat transfer medium from the plant end, directly using the pressure storage device 12 for pressure boosting can obtain a higher pressure for the heat transfer medium. When the pressure storage device 12 is in a stable pressure state, the pressure storage device 12 can buffer and store the heat transfer medium, so that the pressure of the heat transfer medium in the pipeline 10 remains stable, thereby keeping the pressure of the heat transfer medium in the electrostatic adsorption plate 4 connected to the pipeline 10 stable, preventing the heat transfer medium from being severely lost due to the repeated start of the air extraction device 13 caused by the unstable pressure of the heat transfer medium.

[0085] like Figure 1 As shown, preferably, the electrostatic adsorption disk 4 includes an edge region 40 and a central region 41. The pipe 10 includes a first pipe 100 and a second pipe 101. The first pipe 100 is connected to the edge region 40, the heat transfer medium inlet 3, and the vacuum device 13. The second pipe 101 is connected to the central region 41, the heat transfer medium inlet 3, and the vacuum device 13. The edge region 40 can be located at the lower edge of the electrostatic adsorption disk 4, and the central region 41 can be located at the lower center of the electrostatic adsorption disk 4. The electrostatic adsorption disk 4 can be a thin cylinder. The first pipe 100 and the second pipe 101 can be pipes made of metal. Due to structural differences, the edge region 40 and the central region 41 require different heat transfer medium pressures. By setting the first pipe 100 and the second pipe 101 separately, independent control of the heat transfer medium pressure in the edge region 40 and the central region 41 can be achieved.

[0086] Please also refer to Figure 1 and Figure 2 Preferably, the pressure storage device 12 includes a first pressure storage tank 120 and a second pressure storage tank 121, and the control valve group 11 includes a first control valve group 110 and a second control valve group 111. The first pressure storage tank 120 and the first control valve group 110 are disposed in the first pipeline 100, and the second pressure storage tank 121 and the second control valve group 111 are disposed in the second pipeline 101. The controller 14 is connected to the first control valve group 110 and the second control valve group 111. For example, the first pressure storage tank 120 and the second pressure storage tank 121 can be pressure storage cylinders, whose stored heat transfer medium pressure is less than 200 torr (torr, a unit of pressure). The first pressure storage tank 120 and the second pressure storage tank 121 can be adapted and selected according to the heat transfer medium pressure required by the edge region 40 and the central region 41, respectively. The controller 14 and the first control valve group 110 and the second control valve group 111 can be electrically connected via cables.

[0087] Please also refer to Figure 1 , Figure 3 and Figure 4Preferably, the first control valve group 110 includes a first control master valve 1100, and the first pipeline 100 is connected to the heat transfer medium inlet 3 through the first control master valve 1100. The second control valve group 111 includes a second control master valve 1110, and the second pipeline 101 is connected to the heat transfer medium inlet 3 through the second control master valve 1110. The controller 14 is connected to both the first and second control master valves 1100. The first control master valve 1100 can be a pressure control valve. For example, the first control master valve 1100 includes an inlet and an outlet. The inlet of the first control master valve 1100 is connected to the heat transfer medium inlet 3 (for example, the inlet of the first control master valve 1100 has an external thread, and the heat transfer medium inlet 3 has an internal thread, and the two are connected by threads). The outlet of the first control master valve 1100 is connected to the first pipeline 100 (for example, using the same thread connection method as the inlet of the first control master valve 1100). The controller 14, the first control main valve 1100, and the second control main valve 1110 can be electrically connected via cables.

[0088] like Figure 1 As shown, the second control main valve 1110 can be a pressure control valve. The second control main valve 1110 includes an inlet and an outlet. The inlet of the second control main valve 1110 is connected to the heat transfer medium inlet 3, and the outlet of the second control main valve 1110 is connected to the second pipeline 101. The specific connection method can be similar to that of the first control main valve 1100.

[0089] Please also refer to Figure 1 and Figure 5 Preferably, the first pipeline 100 includes a first branch 1000, a second branch 1001, and a first connecting pipe 1002. The first branch 1000 and the second branch 1001 are connected in parallel. One end of the parallel connection of the first branch 1000 and the second branch 1001 is connected to the first control main valve 1100, and the other end is connected to the air extraction device 13. The first pressure tank 120 is disposed in the first branch 1000. The first branch 1000 and the second branch 1001 are connected to the edge region 40 through the first connecting pipe 1002. For example, one parallel connection point of the first branch 1000 and the second branch 1001 is connected to the outlet of the first control main valve 1100, and the other parallel connection point is connected to the air extraction device 13. The first connecting pipe 1002 can be a pipe made of metal. One end of the first connecting pipe 1002 is connected to the edge region 40, and the other end of the first connecting pipe 1002 is connected to the second branch 1001 and extends to connect with the first branch 1000.

[0090] Please also refer to Figure 3 and Figure 5Preferably, the first control valve group 110 further includes a first control valve 1101, a second control valve 1102, a third control valve 1103, a fourth control valve 1104, a fifth control valve 1105, and a first voltage regulator 1106. The first control valve 1101, the second control valve 1102, the third control valve 1103, the fourth control valve 1104, the fifth control valve 1105, and the first voltage regulator 1106 are connected to the controller 14 (e.g., electrically connected via a cable). The first control valve 1101, the second control valve 1102, and the third control valve 1103 are sequentially arranged in the first branch 1000.

[0091] like Figure 5 As shown, the fourth control valve 1104, the fifth control valve 1105, and the first pressure stabilizing device 1106 are sequentially arranged in the second branch 1001 (for example, the fourth control valve 1104, the fifth control valve 1105, and the first pressure stabilizing device 1106 each have an inlet and an outlet, the inlet of the fourth control valve 1104 is connected to the outlet of the first control main valve 1100, the outlet of the fourth control valve 1104 is connected to the inlet of the fifth control valve 1105, the outlet of the fifth control valve 1105 is connected to the inlet of the first pressure stabilizing device 1106, and the outlet of the first pressure stabilizing device 1106 is connected to the air extraction device 13. The aforementioned connection methods can be threaded connections).

[0092] like Figure 5 As shown, the first pressure tank 120 is disposed between the first control valve 1101 and the second control valve 1102 (for example, the first control valve 1101, the first pressure tank 120, the second control valve 1102 and the third control valve 1103 may each include an inlet and an outlet, the inlet of the first control valve 1101 is connected to the outlet of the first control main valve 1100, the outlet of the first control valve 1101 is connected to the inlet of the first pressure tank 120, the outlet of the first pressure tank 120 is connected to the inlet of the second control valve 1102, the outlet of the second control valve 1102 is connected to the inlet of the third control valve 1103, and the outlet of the third control valve 1103 is connected to the air extraction device 13, and the aforementioned connection methods may be threaded connections).

[0093] like Figure 5 As shown, the connection point between the first connecting pipe 1002 and the first branch 1000 is located between the second control valve 1102 and the third control valve 1103 (for example, the first connecting pipe 1002 can be connected to both the outlet of the second control valve 1102 and the inlet of the third control valve 1103). The connection point between the first connecting pipe 1002 and the second branch 1001 is located between the fourth control valve 1104 and the fifth control valve 1105 (for example, the first connecting pipe 1002 can be connected to both the outlet of the fourth control valve 1104 and the inlet of the fifth control valve 1105). The first pressure stabilizing device 1106 may include, but is not limited to, a throttle valve, a pressure stabilizing pump, and a pressure stabilizing valve.

[0094] Please also refer to Figure 1 and Figure 5 Preferably, the second pipeline 101 includes a third branch 1010, a fourth branch 1011, and a second connecting pipe 1012. The third branch 1010 and the fourth branch 1011 are connected in parallel. One end of the parallel connection of the third branch 1010 and the fourth branch 1011 is connected to the second control main valve 1110, and the other end of the parallel connection of the third branch 1010 and the fourth branch 1011 is connected to the air extraction device 13. The second pressure tank 121 is located in the third branch 1010. The third branch 1010 and the fourth branch 1011 are connected to the central region 41 through the second connecting pipe 1012. For example, one of the parallel connection points of the third branch 1010 and the fourth branch 1011 is connected to the outlet of the second control main valve 1110. The other parallel connection point of the third branch 1010 and the fourth branch 1011 is connected to the air extraction device 13. The second connecting pipe 1012 can be a pipe made of metal. One end of the second connecting pipe 1012 is connected to the central region 41, and the other end of the second connecting pipe 1012 is connected to the fourth branch 1011 and extends to connect with the third branch 1010.

[0095] Please also refer to Figure 4 and Figure 5 Preferably, the second control valve group 111 further includes a sixth control valve 1111, a seventh control valve 1112, an eighth control valve 1113, a ninth control valve 1114, a tenth control valve 1115, and a second pressure stabilizing device 1116. The sixth control valve 1111, the seventh control valve 1112, the eighth control valve 1113, the ninth control valve 1114, the tenth control valve 1115, and the second pressure stabilizing device 1116 are connected to the controller 14 (e.g., electrically connected via a cable). The sixth control valve 1111, the seventh control valve 1112, and the eighth control valve 1113 are sequentially arranged in the third branch 1010.

[0096] like Figure 5 As shown, the ninth control valve 1114, the tenth control valve 1115, and the second pressure stabilizing device 1116 are sequentially arranged in the fourth branch 1011 (for example, the ninth control valve 1114, the tenth control valve 1115, and the second pressure stabilizing device 1116 each have an inlet and an outlet, the inlet of the ninth control valve 1114 is connected to the outlet of the second control main valve 1110, the outlet of the ninth control valve 1114 is connected to the inlet of the tenth control valve 1115, the outlet of the tenth control valve 1115 is connected to the inlet of the second pressure stabilizing device 1116, and the outlet of the second pressure stabilizing device 1116 is connected to the air extraction device 13. The aforementioned connection methods can be threaded connections).

[0097] like Figure 5As shown, the second pressure tank 121 is disposed between the sixth control valve 1111 and the seventh control valve 1112 (for example, the sixth control valve 1111, the second pressure tank 121, the seventh control valve 1112 and the eighth control valve 1113 each have an inlet and an outlet, the inlet of the sixth control valve 1111 is connected to the outlet of the second control main valve 1110, the outlet of the sixth control valve 1111 is connected to the inlet of the second pressure tank 121, the outlet of the second pressure tank 121 is connected to the inlet of the seventh control valve 1112, the outlet of the seventh control valve 1112 is connected to the inlet of the eighth control valve 1113, and the outlet of the eighth control valve 1113 is connected to the air extraction device 13. The aforementioned connection methods can be threaded connections).

[0098] like Figure 5 As shown, the connection point between the second connecting pipe 1012 and the third branch 1010 is located between the seventh control valve 1112 and the eighth control valve 1113 (for example, the second connecting pipe 1012 can be connected to both the outlet of the seventh control valve 1112 and the inlet of the eighth control valve 1113 simultaneously). The connection point between the second connecting pipe 1012 and the fourth branch 1011 is located between the ninth control valve 1114 and the tenth control valve 1115 (for example, the second connecting pipe 1012 can be connected to both the outlet of the ninth control valve 1114 and the inlet of the tenth control valve 1115 simultaneously). The second pressure regulating device 1116 may include, but is not limited to, a throttle valve, a pressure regulating pump, and a pressure regulating valve.

[0099] like Figure 6 As shown, in another embodiment, a pressure control method is provided, which is applied to a pressure control system 1, and includes the following steps:

[0100] S11: Controls the transfer of wafer 2 to electrostatic adsorption disk 4;

[0101] S12: Control the first control valve 1101 and the sixth control valve 1111 to open, and control the second control valve 1102 and the seventh control valve 1112 to close, so that the heat transfer medium enters the first pressure tank 120 through the first control main valve 1100 until the pressure in the first pressure tank 120 reaches a first predetermined pressure value, and then allows the heat transfer medium to enter the second pressure tank 121 through the second control main valve 1110 until the pressure in the second pressure tank 121 reaches a second predetermined pressure value. In step S12, the states of each control valve are as follows: Figure 5 As shown, Figure 5 Control valves with blank spaces are in the open state, and control valves with black spaces are in the closed state. That is, the first control valve 1101 and the sixth control valve 1111 are open, and the second control valve 1102, the third control valve 1103, the fourth control valve 1104, the fifth control valve 1105, the seventh control valve 1112, the eighth control valve 1113, the ninth control valve 1114, and the tenth control valve 1115 are closed.

[0102] S13: Control the wafer 2 to be positioned on the electrostatic adsorption disk 4; and

[0103] S14: Close the first control valve 1101 and the sixth control valve 1111, and open the second control valve 1102 and the seventh control valve 1112 to allow the heat transfer medium in the first pressure tank 120 and the second pressure tank 121 to enter the electrostatic adsorption plate 4. In step S14, the states of each control valve are as follows: Figure 7 As shown, Figure 7 Control valves with blank spaces are in the open state, and control valves with black spaces are in the closed state. That is, the second control valve 1102 and the seventh control valve 1112 are open, and the first control valve 1101, the third control valve 1103, the fourth control valve 1104, the fifth control valve 1105, the sixth control valve 1111, the eighth control valve 1113, the ninth control valve 1114, and the tenth control valve 1115 are closed.

[0104] While wafer 2 is being transferred to electrostatic adsorption tray 4, the first control valve 1101 and the sixth control valve 1111 are opened, and the second control valve 1102 and the seventh control valve 1112 are closed. This allows the first pressure tank 120 and the second pressure tank 121 to enter a pressurization state, meaning that wafer 2 transfer and pressure boosting of the pressure storage device 12 occur simultaneously. Thus, by the time wafer 2 is placed on electrostatic adsorption tray 4, the first pressure tank 120 has already reached a first predetermined pressure value, and the second pressure tank 121 has reached a second predetermined pressure value. This allows wafer 2 to be cooled directly using a high-pressure heat transfer medium without waiting during processing. This eliminates the pressure boosting waiting time and improves the processing efficiency of wafer 2. Figure 8 As shown in the figure, the dashed curve is the pressure control curve of the traditional pressure control method, and the solid curve is the pressure control curve of the method of this embodiment. When the predetermined pressure value (first predetermined pressure value and / or second predetermined pressure value) is 40 Torr, the time to reach the predetermined pressure value using the method of this embodiment is less than that of the traditional pressure control method.

[0105] Please also refer to Figure 1 , Figure 9 and Figure 10 ,in, Figure 10 A control valve with blank space is in the open state, and a control valve with black space is in the closed state. In another embodiment, a pressure stabilization method is provided, applied to a pressure control system 1, comprising the following steps:

[0106] S21: Control the first control valve 1101 and the sixth control valve 1111 to close so that the pipeline 10 between the first control main valve 1100 and the first pressure tank 120 is disconnected, and the pipeline 10 between the second control main valve 1110 and the second pressure tank 121 is disconnected.

[0107] S22: Control the second control valve 1102 and the seventh control valve 1112 to open, so as to connect the first pressure tank 120 with the edge region 40 and the second pressure tank 121 with the center region 41;

[0108] S23: Control the fourth control valve 1104 and the ninth control valve 1114 to open, so that the first control main valve 1100 is connected to the edge region 40, and the second control main valve 1110 is connected to the center region 41.

[0109] S24: Control the third control valve 1103 and the eighth control valve 1113 to close, thereby disconnecting the pipeline 10 between the connection point of the first connecting pipe 1002 and the first branch 1000 and the air extraction device 13, and disconnecting the pipeline 10 between the connection point of the second connecting pipe 1012 and the third branch 1010 and the air extraction device 13; and

[0110] S25: Control the fifth control valve 1105, the first pressure stabilizing device 1106, the tenth control valve 1115, the second pressure stabilizing device 1116 and the air extraction device 13 to open, so that the edge area 40 is connected to the air extraction device 13 through the first connecting pipe 1002 and the second branch 1001, and the central area 41 is connected to the air extraction device 13 through the second connecting pipe 1012 and the fourth branch 1011.

[0111] By controlling the opening of the second control valve 1102 and the seventh control valve 1112, the first pressure tank 120 and the edge region 40 are connected, and the second pressure tank 121 and the central region 41 are connected. By controlling the opening of the fifth control valve 1105, the first pressure stabilizing device 1106, the tenth control valve 1115, the second pressure stabilizing device 1116 and the air extraction device 13, the edge region 40 is connected to the air extraction device 13 via the first connecting pipe 1002 and the second branch 1001, and the central region 41 is connected to the air extraction device 13 via the second connecting pipe 1012 and the fourth branch 1011.

[0112] In this way, the edge region 40 is simultaneously connected to both the first pressure stabilizing device 1106 and the first pressure storage tank 120. Even if the pressure of the heat transfer medium entering the edge region 40 through the fourth control valve 1104 fluctuates significantly, the fluctuations will be stored and buffered by the first pressure stabilizing device 1106 and the first pressure storage tank 120, thereby forming a relatively stable heat transfer medium pressure in the edge region 40. This also reduces the amount of heat transfer medium extracted from the edge region 40 by the extraction device 13. Similarly, the central region 41 is simultaneously connected to both the second pressure stabilizing device 1116 and the second pressure storage tank 121. Even if the pressure of the heat transfer medium entering the central region 41 through the ninth control valve 1114 fluctuates significantly, the fluctuations will be stored and buffered by the second pressure stabilizing device 1116 and the second pressure storage tank 121, thereby forming a relatively stable heat transfer medium pressure in the central region 41. This also reduces the amount of heat transfer medium extracted from the central region 41 by the extraction device 13.

[0113] The pressure control system, pressure control method, and voltage stabilization method provided in the embodiments of this application have been described in detail above. For those skilled in the art, based on the ideas of the embodiments of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application. All equivalent modifications or changes made in accordance with the spirit and technical concept of this application should still be covered by the claims of this application.

Claims

1. A pressure control system (1) for controlling the pressure of a thermally conductive medium on the back side of a wafer (2), characterized in that, include: Pipeline (10), one end of which is connected to the heat-conducting medium inlet (3), and the other end of the pipeline (10) is connected to the electrostatic adsorption disk (4); A control valve assembly (11) is provided in the pipeline (10); A pressure storage device (12) is provided in the pipeline (10). The pressure storage device (12) includes a pressure boosting state and a pressure stabilizing state. In the pressure boosting state, the pressure storage device (12) is used to pressurize the heat-conducting medium. In the pressure stabilizing state, the pressure storage device (12) is used to buffer and store the heat-conducting medium, which is helium. An air extraction device (13) connected to the pipeline (10); and A controller (14) is connected to the control valve group (11) and the vacuum device (13). The controller (14) generates control commands, and the control valve group (11) opens and closes based on the control commands to control the heat transfer medium to enter and / or exit the pressure storage device (12). The electrostatic adsorption disk (4) includes an edge region (40) and a central region (41). The edge region (40) is located at the lower edge of the electrostatic adsorption disk (4), and the central region (41) is located at the lower center of the electrostatic adsorption disk (4). The pipeline (10) includes a first pipeline (100) and a second pipeline (101). The first pipeline (100) and the edge region (40) are connected. The heat transfer medium inlet (3) and the air extraction device (13) are connected. The second pipeline (101) is connected to the central area (41), the heat transfer medium inlet (3) and the air extraction device (13). The first pipeline (100) includes a first branch (1000), a second branch (1001) and a first connecting pipe (1002). The first branch (1000) and the second branch (1001) are connected in parallel. One end of the first branch (1000) and the second branch (1001) connected in parallel is connected to the first control main valve (1100). The other end of the first branch (1000) and the second branch (1001) connected in parallel is connected to the air extraction device (13). A pressure tank (120) is disposed in the first branch (1000). The first branch (1000) and the second branch (1001) are connected to the edge region (40) through a first connecting pipe (1002). One end of the first connecting pipe (1002) is connected to the edge region (40), and the other end of the first connecting pipe (1002) is connected to the second branch (1001) and extends to connect with the first branch (1000). The second pipeline (101) includes a third branch (1010), a fourth branch (1011), and a second connecting pipe (1012). The third branch (1010) and the fourth branch (1011) are connected in parallel. 10) One end of the third branch (1010) and the fourth branch (1011) are connected to the second control main valve (1110). The other end of the third branch (1010) and the fourth branch (1011) are connected to the air extraction device (13). The second pressure tank (121) is located in the third branch (1010). The third branch (1010) and the fourth branch (1011) are connected to the central area (41) through the second connecting pipe (1012). One end of the second connecting pipe (1012) is connected to the central area (41). The other end of the second connecting pipe (1012) is connected to the fourth branch (1011) and extends to connect with the third branch (1010).

2. The pressure control system (1) according to claim 1, characterized in that, The pressure storage device (12) includes a first pressure storage tank (120) and a second pressure storage tank (121). The control valve group (11) includes a first control valve group (110) and a second control valve group (111). The first pressure storage tank (120) and the first control valve group (110) are disposed in the first pipeline (100). The second pressure storage tank (121) and the second control valve group (111) are disposed in the second pipeline (101). The controller (14) is connected to the first control valve group (110) and the second control valve group (111).

3. The pressure control system (1) according to claim 2, characterized in that, The first control valve group (110) includes a first control master valve (1100), and the first pipeline (100) is connected to the heat transfer medium inlet (3) through the first control master valve (1100). The second control valve group (111) includes a second control master valve (1110), and the second pipeline (101) is connected to the heat transfer medium inlet (3) through the second control master valve (1110). The controller (14) is connected to the first control master valve (1100) and the second control master valve (1110).

4. The pressure control system (1) according to claim 3, characterized in that, The first control valve group (110) further includes a first control valve (1101), a second control valve (1102), a third control valve (1103), a fourth control valve (1104), a fifth control valve (1105), and a first voltage regulator (1106). The first control valve (1101), the second control valve (1102), the third control valve (1103), the fourth control valve (1104), the fifth control valve (1105), and the first voltage regulator (1106) are connected to the controller (14). The first control valve (1101), the second control valve (1102), and the third control valve (1103) are sequentially arranged in the first branch. (1000), the fourth control valve (1104), the fifth control valve (1105) and the first pressure stabilizing device (1106) are sequentially arranged in the second branch (1001), wherein the first pressure tank (120) is arranged between the first control valve (1101) and the second control valve (1102), the connection point of the first connecting pipe (1002) and the first branch (1000) is arranged between the second control valve (1102) and the third control valve (1103), and the connection point of the first connecting pipe (1002) and the second branch (1001) is arranged between the fourth control valve (1104) and the fifth control valve (1105).

5. The pressure control system (1) according to claim 4, characterized in that, The second control valve group (111) further includes a sixth control valve (1111), a seventh control valve (1112), an eighth control valve (1113), a ninth control valve (1114), a tenth control valve (1115), and a second pressure stabilizing device (1116). The sixth control valve (1111), the seventh control valve (1112), the eighth control valve (1113), the ninth control valve (1114), the tenth control valve (1115), and the second pressure stabilizing device (1116) are connected to the controller (14). The sixth control valve (1111), the seventh control valve (1112), and the eighth control valve (1113) are sequentially arranged in the third branch. (1010) The ninth control valve (1114), the tenth control valve (1115) and the second pressure stabilizing device (1116) are sequentially arranged in the fourth branch (1011). The second pressure tank (121) is arranged between the sixth control valve (1111) and the seventh control valve (1112). The connection point of the second connecting pipe (1012) and the third branch (1010) is arranged between the seventh control valve (1112) and the eighth control valve (1113). The connection point of the second connecting pipe (1012) and the fourth branch (1011) is arranged between the ninth control valve (1114) and the tenth control valve (1115).

6. A pressure control method applied to the pressure control system (1) according to claim 5, characterized in that, Includes the following steps: Control the transfer of the wafer (2) to the electrostatic adsorption disk (4); The first control valve (1101) and the sixth control valve (1111) are opened, and the second control valve (1102) and the seventh control valve (1112) are closed, so that the heat transfer medium enters the first pressure tank (120) through the first control main valve (1100) until the pressure of the first pressure tank (120) reaches a first predetermined pressure value, and the heat transfer medium enters the second pressure tank (121) through the second control main valve (1110) until the pressure of the second pressure tank (121) reaches a second predetermined pressure value; Controlling the wafer (2) to be placed on the electrostatic adsorption disk (4); and The first control valve (1101) and the sixth control valve (1111) are closed, and the second control valve (1102) and the seventh control valve (1112) are opened, so that the heat-conducting medium in the first pressure tank (120) and the second pressure tank (121) enters the electrostatic adsorption plate (4).

7. A voltage stabilization method applied to the voltage control system (1) according to claim 5, characterized in that, Includes the following steps: Control the first control valve (1101) and the sixth control valve (1111) to close so that the pipeline (10) between the first control main valve (1100) and the first pressure tank (120) is disconnected, and the pipeline (10) between the second control main valve (1110) and the second pressure tank (121) is disconnected; The second control valve (1102) and the seventh control valve (1112) are opened to connect the first pressure tank (120) and the edge region (40), and to connect the second pressure tank (121) and the center region (41); The fourth control valve (1104) and the ninth control valve (1114) are opened to connect the first control main valve (1100) with the edge region (40) and to connect the second control main valve (1110) with the center region (41). Control the third control valve (1103) and the eighth control valve (1113) to close, thereby disconnecting the pipeline (10) between the connection point of the first connecting pipe (1002) and the first branch (1000) and the suction device (13), and disconnecting the pipeline (10) between the connection point of the second connecting pipe (1012) and the third branch (1010) and the suction device (13); and The fifth control valve (1105), the first pressure stabilizing device (1106), the tenth control valve (1115), the second pressure stabilizing device (1116), and the air extraction device (13) are opened to allow the edge region (40) to be connected to the air extraction device (13) via the first connecting pipe (1002) and the second branch (1001), and to allow the center region (41) to be connected to the air extraction device (13) via the second connecting pipe (1012) and the fourth branch (1011).

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