Pressure control device and pressure control method

Abstract

The embodiment of the present invention discloses a pressure control device and a pressure control method. The pressure control device includes: a first pressure controller, a first isolation valve, a second isolation valve, a third isolation valve and a vacuum pump; when the first isolation valve, the second isolation valve and the third isolation valve are in an open state according to a preset sequence, the vacuum pump adsorbs the wafer on the wafer temperature control base; the first pressure controller controls the pressure of the gas between the wafer and the wafer temperature control base to be a first preset pressure; a part of the gas enters between the wafer and the wafer temperature control base through the first pressure controller, the first isolation valve and the second isolation valve, and the other part is drawn away by the vacuum pump through the third isolation valve. The technical solution of the embodiment of the present invention fills the space between the wafer and the wafer temperature control base with gas, and accurately controls the pressure of the gas filled between the wafer and the wafer temperature control base, thereby improving the surface uniformity of the wafer and the thermal conductivity of the wafer and the wafer temperature control base.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing technology, and in particular to a pressure control device and a pressure control method. Background Art

[0002] In the plasma etching process and chemical vapor deposition process, wafer temperature control is one of the key technologies. In the wafer temperature control technology, the wafer temperature control base (heater) is a key component. From a microscopic perspective, the surface where the wafer contacts the wafer temperature control base is uneven, there are contact points on the contact surface, and there are gaps formed due to the roughness. Heat conduction needs to be carried out through a medium. The wafer is in a vacuum environment. If heat is transferred solely by the contact area, the thermal conductivity of the wafer will be very poor, resulting in uneven temperature distribution in different areas of the wafer.

[0003] Therefore, introducing a gas with a high thermal conductivity into the gap between the wafer and the wafer temperature control base and controlling the pressure of the gas introduced between the wafer and the wafer temperature control base have become urgent issues to be solved. Summary of the Invention

[0004] The present invention provides a pressure control device and a pressure control method to achieve precise control of the pressure of the gas filled between the wafer and the wafer temperature control base, improve the surface uniformity of the wafer, and enhance the thermal conductivity of the wafer and the wafer temperature control base.

[0005] According to one aspect of the present invention, a pressure control device is provided for controlling the gas pressure between a wafer and a wafer temperature control base; the pressure control device comprises: a first pressure controller, a first isolation valve, a second isolation valve, a third isolation valve, and a vacuum pump;

[0006] One end of the first isolation valve is connected to the first pressure controller, and the other end of the first isolation valve is connected to one end of the second isolation valve and one end of the third isolation valve respectively; the other end of the second isolation valve is connected to the wafer and the wafer temperature control base; the other end of the third isolation valve is connected to the vacuum pump;

[0007] The vacuum pump is used to adsorb the wafer on the wafer temperature control base when the first isolation valve, the second isolation valve and the third isolation valve are in the open state according to a preset sequence;

[0008] The first pressure controller is used to control the pressure of the gas entering between the wafer and the wafer temperature control base to a first preset pressure; wherein, a part of the gas enters between the wafer and the wafer temperature control base through the first pressure controller, the first isolation valve and the second isolation valve, and the other part of the gas is drawn away by the vacuum pump through the third isolation valve.

[0009] Optionally, the pressure control device further includes: a chamber vacuum system; the chamber vacuum system includes a chamber, a fourth isolation valve, and a second pressure controller; the wafer and the wafer temperature control base are placed in the chamber, and the chamber is used to perform a thin film deposition process on the wafer; the fourth isolation valve is connected between the chamber and the second pressure controller; and the second pressure controller is connected between the fourth isolation valve and the vacuum pump;

[0010] The vacuum pump is also used to control the chamber to reach a vacuum state when the second pressure controller and the fourth isolation valve are in the open state;

[0011] The second pressure controller is used to adjust the opening of the fourth isolation valve to control the pressure of the chamber to be stable at a second preset pressure; wherein the first preset pressure is less than the second preset pressure.

[0012] Optionally, the pressure control device further comprises: a fifth isolation valve; one end of the fifth isolation valve is connected to the chamber, and the other end of the fifth isolation valve is connected to the first isolation valve and the third isolation valve;

[0013] The fifth isolation valve is used to communicate with the second isolation valve when the third isolation valve is in a closed state and the first pressure controller is in a stopped state, so that the pressure between the wafer and the wafer temperature control base is the same as the pressure in the chamber.

[0014] Optionally, the pressure control device further comprises: a monitoring unit;

[0015] The monitoring unit is used to alarm when the difference between the pressure of the gas between the wafer and the wafer temperature control base and the second preset pressure is less than the first preset difference; and / or, the monitoring unit is used to alarm when the difference between the pressure of the gas between the wafer and the wafer temperature control base and the first preset pressure is greater than the second preset difference.

[0016] Optionally, the pressure control device further comprises: a flow limiting gasket; the flow limiting gasket is arranged between the first isolation valve and the third isolation valve;

[0017] Restrictor gaskets are used to control the amount of gas drawn away by the vacuum pump.

[0018] Optionally, the aperture parameter selection of the flow limiting gasket is positively correlated with the gas flow measurement range of the first pressure controller.

[0019] According to another aspect of the present invention, a pressure control method is provided, the pressure control method comprising:

[0020] Control the first isolation valve, the second isolation valve and the third isolation valve to be in an open state according to a preset sequence;

[0021] Control the vacuum pump to adsorb the wafer onto the wafer temperature control base;

[0022] The pressure of the gas introduced between the wafer and the wafer temperature control base is controlled by a first pressure controller to be a first preset pressure.

[0023] Optionally, before controlling the first isolation valve, the second isolation valve, and the third isolation valve to be in an open state in a preset sequence, the method further includes:

[0024] Control the second pressure controller and the fourth isolation valve to be in an open state;

[0025] The chamber is controlled to reach a vacuum state by a vacuum pump;

[0026] The opening of the fourth isolation valve is adjusted by the second pressure controller to control the pressure of the chamber to be stable at a second preset pressure; wherein the first preset pressure is less than the second preset pressure.

[0027] Optionally, after controlling the vacuum pump to adsorb the wafer onto the wafer temperature control base, the method further includes:

[0028] Detect the pressure of the gas between the wafer and the wafer temperature control base;

[0029] An alarm is triggered when the difference between the pressure of the gas between the wafer and the wafer temperature control base and the second preset pressure is less than the first preset difference.

[0030] Optionally, after controlling the pressure of the gas between the wafer and the wafer temperature control base to be a first preset pressure by the first pressure controller, the method further includes:

[0031] Detect the pressure of the gas between the wafer and the wafer temperature control base;

[0032] An alarm is triggered when the difference between the pressure of the gas between the wafer and the wafer temperature control base and the first preset pressure is greater than the second preset difference.

[0033] The technical solution of the embodiment of the present invention is to set a pressure control device, open the first isolation valve, the second isolation valve and the third isolation valve in a preset order, and the residual gas in the pipeline is discharged, thereby improving the purity of the gas entering the space between the wafer and the wafer temperature control base. When the first isolation valve, the second isolation valve and the third isolation valve are all in the open state, the gas between the wafer and the wafer temperature control base can be evacuated by a vacuum pump, so that the gas pressure between the wafer and the wafer temperature control base is less than the pressure on the front of the wafer, so that the wafer is adsorbed on the wafer temperature control base, so that the narrow gap between the wafer and the wafer temperature control base forms a closed environment. Set the pressure of the first pressure controller and start working. After the gas passes through the first pressure controller, part of the gas enters between the wafer and the wafer temperature control base through the first pressure controller, the first isolation valve and the second isolation valve, and the other part of the gas is drawn away by the vacuum pump through the third isolation valve, so that the gas pressure between the wafer and the wafer temperature control base reaches the first preset pressure and maintains a constant pressure, thereby achieving precise control of the pressure of the gas filled between the wafer and the wafer temperature control base, improving the surface uniformity of the wafer, and improving the thermal conductivity of the wafer and the wafer temperature control base.

[0034] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 is a structural schematic diagram of a pressure control device provided according to an embodiment of the present invention;

[0037] Figure 2 is a partial enlarged view of the surface between the wafer and the wafer temperature control base provided according to an embodiment of the present invention;

[0038] Figure 3 2 is a schematic structural diagram of a flow-limiting gasket in a pressure control device provided in an embodiment of the present invention;

[0039] Figure 4 Schematic diagram showing the effect of selecting current limiting gaskets with different apertures on the actual pressure between the wafer and the wafer temperature control base when the set pressure range of the first pressure controller provided by an embodiment of the present invention is 0 to 100 Torr;

[0040] Figure 5Schematic diagram of the effect of selecting a 0.3 mm aperture current limiting gasket on the actual pressure between the wafer and the wafer temperature control base when the set pressure range of the first pressure controller provided by an embodiment of the present invention is 0 to 100 Torr;

[0041] Figure 6 2. It is a schematic diagram showing the relationship between the pressure and the gas flow between the wafer and the wafer temperature control base when the pressure control device provided by an embodiment of the present invention is in operation;

[0042] Figure 7 is a flow chart of a pressure control method provided according to an embodiment of the present invention;

[0043] Figure 8 yes Figure 7 Schematic diagram of the structure of the pressure control device corresponding to S110;

[0044] Figure 9 is a flow chart of another pressure control method provided according to an embodiment of the present invention;

[0045] Figure 10 yes Figure 9 Schematic diagram of the structure of the pressure control device corresponding to S217;

[0046] Figure 11 yes Figure 9 A schematic diagram of the structure of the pressure control device corresponding to S219;

[0047] Figure 12 is a flow chart of another pressure control method provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0048] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0049] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. 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 clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0050] Figure 1 1 is a schematic diagram of the structure of a pressure control device provided according to an embodiment of the present invention. The pressure control device is used to control the gas pressure between the wafer 10 and the wafer temperature control base 20; the pressure control device includes: a first pressure controller 30, a first isolation valve V1, a second isolation valve V2, a third isolation valve V3 and a vacuum pump 40; one end of the first isolation valve V1 is connected to the first pressure controller 30, and the other end of the first isolation valve V1 is connected to one end of the second isolation valve V2 and one end of the third isolation valve V3 respectively; the other end of the second isolation valve V2 is connected to the space between the wafer 10 and the wafer temperature control base 20; the other end of the third isolation valve V3 is connected to the vacuum pump 40. 0 connection; the vacuum pump 40 is used to adsorb the wafer 10 on the wafer temperature control base 20 when the first isolation valve V1, the second isolation valve V2 and the third isolation valve V3 are in the open state according to a preset sequence; the first pressure controller 30 is used to control the pressure of the gas between the wafer 10 and the wafer temperature control base 20 to be a first preset pressure; wherein, a part of the gas enters between the wafer 10 and the wafer temperature control base 20 through the first pressure controller 30, the first isolation valve V1 and the second isolation valve V2, and the other part of the gas is extracted by the vacuum pump 40 through the third isolation valve V3.

[0051] In an embodiment of the present invention, the wafer temperature control base 20 is a key component for heating and temperature control of the wafer 10 in the semiconductor manufacturing process. The wafer temperature control base 20 has two key functions: one is to fix the wafer 10, and the other is to control the temperature of the wafer 10 through heat conduction with the wafer 10. The first pressure controller 30 is a universal pressure controller (UPC), which is used to control the constant pressure of the inert gas between the wafer 10 and the wafer temperature control base 20. The inert gas is used as a medium for transferring heat to help control the temperature of the wafer 10. The first isolation valve V1, the second isolation valve V2, and the third isolation valve V3 are all valves that can adjust the gas flow.

[0052] For example, before the wafer 10 enters the high-temperature process step, an inert gas (such as argon) will be filled between the wafer 10 and the wafer temperature control base 20, and a pressure control device composed of UPC, a first isolation valve V1, a second isolation valve V2, a third isolation valve V3 and a vacuum pump 40 will be used to maintain a constant gas pressure level between the wafer 10 and the wafer temperature control base 20, or dynamically adjust it according to process requirements.

[0053] Specifically, before implementing the gas pressure control between the wafer 10 and the wafer temperature control base 20, it is necessary to ensure that the wafer 10 has been placed on the surface of the wafer temperature control base 20, and control the pressure of the chamber 50 where the wafer 10 and the wafer temperature control base 20 are located to reach the working pressure. Generally, the working pressure of the chamber 50 is controlled between 10-100Torr. The preset sequence is a pre-set sequence of opening the first isolation valve V1, the second isolation valve V2, and the third isolation valve V3. For example, the isolation valves are opened in sequence in the order of first opening the third isolation valve V3, then opening the first isolation valve V1, and finally opening the second isolation valve V2. As shown in FIG. Figure 1 As shown, according to the preset sequence, the third isolation valve V3 is opened first to discharge the residual gas in the device. Then the first isolation valve V1 is opened. The pipelines containing the first isolation valve V1 and the third isolation valve V3 are connected to the vacuum pump 40. The residual gas in the pipelines is discharged, improving the purity of the gas between the wafer 10 and the wafer temperature control base 20. Finally, the second isolation valve V2 is opened. At this time, the first isolation valve V1, the second isolation valve V2, and the third isolation valve V3 are all in the open state. The vacuum pump 40 can be used to evacuate the gas between the wafer 10 and the wafer temperature control base 20, making the gas pressure between the wafer 10 and the wafer temperature control base 20 lower than the pressure on the front of the wafer 10, thereby causing the wafer 10 to be adsorbed on the wafer temperature control base 20, so that the narrow gap between the wafer 10 and the wafer temperature control base 20 forms a closed environment.

[0054] The first preset pressure is the pre-set working pressure of the first pressure controller 30. The first preset pressure is lower than the pressure of the chamber 50. For example, the pressure of the chamber 50 is 50 Torr, and the first preset pressure is 30 Torr. The first pressure controller 30 sets a pressure of 30 Torr and starts working. At this time, part of the gas enters between the wafer 10 and the wafer temperature control base 20 through the first pressure controller 30, the first isolation valve V1 and the second isolation valve V2, and the other part of the gas is drawn away by the vacuum pump 40 through the third isolation valve V3. The gas pressure between the wafer 10 and the wafer temperature control base 20 reaches the first preset pressure and maintains a constant pressure.

[0055] The technical solution of the embodiment of the present invention is to set a pressure control device, open the first isolation valve, the second isolation valve and the third isolation valve in a preset order, and the residual gas in the pipeline is discharged, thereby improving the purity of the gas entering the space between the wafer and the wafer temperature control base. When the first isolation valve, the second isolation valve and the third isolation valve are all in the open state, the gas between the wafer and the wafer temperature control base can be evacuated by a vacuum pump, so that the gas pressure between the wafer and the wafer temperature control base is less than the pressure on the front of the wafer, so that the wafer is adsorbed on the wafer temperature control base, so that the narrow gap between the wafer and the wafer temperature control base forms a closed environment. Set the pressure of the first pressure controller and start working. After the gas passes through the first pressure controller, part of the gas enters between the wafer and the wafer temperature control base through the first pressure controller, the first isolation valve and the second isolation valve, and the other part of the gas is drawn away by the vacuum pump through the third isolation valve, so that the gas pressure between the wafer and the wafer temperature control base reaches the first preset pressure and maintains a constant pressure, thereby achieving precise control of the pressure of the gas filled between the wafer and the wafer temperature control base, improving the surface uniformity of the wafer, and improving the thermal conductivity of the wafer and the wafer temperature control base.

[0056] Based on the technical solution of the above invention embodiment, Figure 1 Optionally, the pressure control device also includes: a chamber vacuum system; the chamber vacuum system includes a chamber 50, a fourth isolation valve V4 and a second pressure controller 60; the wafer 10 and the wafer temperature control base 20 are placed in the chamber 50, and the chamber 50 is used to perform a thin film deposition process on the wafer 10; the fourth isolation valve V4 is connected between the chamber 50 and the second pressure controller 60; the second pressure controller 60 is connected between the fourth isolation valve V4 and the vacuum pump 40; the vacuum pump 40 is also used to control the chamber 50 to reach a vacuum state when the second pressure controller 60 and the fourth isolation valve V4 are in an open state; the second pressure controller 60 is used to adjust the opening of the fourth isolation valve V4 to control the pressure of the chamber 50 to be stable at a second preset pressure; wherein the first preset pressure is less than the second preset pressure.

[0057] In an embodiment of the present invention, the chamber vacuum system is a place for performing a chemical vapor deposition (CVD) process. When the fourth isolation valve V4, the second pressure controller 60 and the vacuum pump 40 are all in the open state, the chamber 50 forms a vacuum-sealed environment. The wafer 10 and the wafer temperature control base 20 are both placed in the chamber 50, and the wafer 10 is placed on the surface of the wafer temperature control base 20 and heated to above 300 degrees Celsius. At the same time, the process gas enters the chamber 50, and the second pressure controller 60 adjusts the pressure in the chamber 50 so that the pressure in the chamber 50 is maintained at a stable process pressure, such as a second preset pressure, and the second preset pressure can be set within the range of 0-100Torr.

[0058] Based on the technical solution of the above invention embodiment, Figure 1 Optionally, the pressure control device also includes: a fifth isolation valve V5; one end of the fifth isolation valve V5 is connected to the chamber 50, and the other end of the fifth isolation valve V5 is connected to the first isolation valve V1 and the third isolation valve V3; the fifth isolation valve V5 is used to communicate with the second isolation valve V2 when the third isolation valve V3 is in a closed state and the first pressure controller 30 is in a stopped state, so that the pressure between the wafer 10 and the wafer temperature control base 20 is the same as the pressure in the chamber 50.

[0059] In this embodiment of the present invention, after the thin film deposition process on wafer 10 is completed, the pressure of first pressure controller 30 is set to the pressure of chamber 50, so that the pressure between wafer 10 and wafer temperature-controlled pedestal 20 approaches the pressure of chamber 50, and the wafer is released for the first time. Then, third isolation valve V3 is controlled to close, fifth isolation valve V5 is opened, and first pressure controller 30 is controlled to be in a stopped state. Chamber 50 is connected to wafer 10 and wafer temperature-controlled pedestal 20, ensuring that the pressure between wafer 10 and wafer temperature-controlled pedestal 20 is exactly the same as the pressure in chamber 50. Wafer 10 is released for the second time, at which point wafer 10 is completely released.

[0060] Based on the technical solution of the above invention embodiment, Figure 1 Optionally, the pressure control device further includes: a monitoring unit 70; the monitoring unit 70 is used to alarm when the difference between the pressure of the gas between the wafer 10 and the wafer temperature control base 20 and the second preset pressure is less than the first preset difference; and / or, the monitoring unit 70 is used to alarm when the difference between the pressure of the gas between the wafer 10 and the wafer temperature control base 20 and the first preset pressure is greater than the second preset difference.

[0061] In an embodiment of the present invention, the monitoring unit 70 may be a pressure gauge and further includes an alarm unit. The first preset difference is the maximum difference between the preset pressure of the gas between the wafer 10 and the wafer temperature-controlled pedestal 20 and a second preset pressure. Exemplarily, the first preset difference is 10 Torr. After opening the first isolation valve V1, the second isolation valve V2, the third isolation valve V3, and the vacuum pump 40, the vacuum pump 40 is connected to the wafer 10 and the wafer temperature-controlled pedestal 20, adsorbing the wafer 10 onto the wafer temperature-controlled pedestal 20. A wafer 10 adsorption test is performed, comparing the pressure of the gas between the wafer 10 and the wafer temperature-controlled pedestal 20 with the pressure within the chamber 50, i.e., the second preset pressure. If the difference between the pressure of the gas between the wafer 10 and the wafer temperature-controlled pedestal 20 and the second preset pressure is less than the first preset difference, it indicates that the wafer 10 is not fully adsorbed, indicating that the wafer 10 or the wafer temperature-controlled pedestal 20 is in an abnormal state, and an alarm is required to alert personnel to address the problem. For example, the second preset pressure is 50 Torr, and the first preset difference is 10 Torr. When the pressure of the gas between the wafer 10 and the wafer temperature control base 20 is 45 Torr, the difference between the pressure of the gas between the wafer 10 and the wafer temperature control base 20 and the second preset pressure is 5 Torr, which is less than 10 Torr. The wafer 10 is not completely adsorbed, and an alarm is required to remind the staff to handle it.

[0062] The second preset difference is the minimum value of the difference between the preset pressure of the gas between the wafer 10 and the wafer temperature control base 20 and the first preset pressure. Exemplarily, the second preset difference is 5 Torr. During the thin film deposition process on the wafer 10, the pressure of the gas between the wafer 10 and the wafer temperature control base 20 is monitored. If the pressure of the gas between the wafer 10 and the wafer temperature control base 20 deviates, an alarm is issued. Exemplarily, the second preset pressure in the chamber 50 is set to 50 Torr, the first preset pressure is set to 30 Torr, and the pressure of the gas between the wafer 10 and the wafer temperature control base 20 is monitored. When the pressure of the gas between the wafer 10 and the wafer temperature control base 20 is greater than 35 Torr or less than 25 Torr, it means that the difference between the pressure of the gas between the wafer 10 and the wafer temperature control base 20 and the first preset pressure is greater than the second preset difference, indicating that the pressure of the gas between the wafer 10 and the wafer temperature control base 20 has deviated, an alarm is issued to remind the staff to handle it.

[0063] Based on the technical solution of the above invention embodiment, Figure 1 Optionally, the pressure control device further includes: a flow limiting gasket 80; the flow limiting gasket 80 is arranged between the first isolation valve V1 and the third isolation valve V3; the flow limiting gasket 80 is used to control the amount of gas drawn away by the vacuum pump 40.

[0064] In an embodiment of the present invention, after the wafer 10 is adsorbed on the wafer temperature control base 20, the pressure of the first pressure controller 30 is set and the operation is started. After the gas passes through the first pressure controller 30, a part of the gas passes through the first pressure controller 30, the first isolation valve V1 and the second isolation valve V2 into the space between the wafer 10 and the wafer temperature control base 20, and the other part of the gas is drawn away by the vacuum pump 40 through the third isolation valve V3, so that the gas pressure between the wafer 10 and the wafer temperature control base 20 reaches the first preset pressure and maintains a constant pressure. The flow limiting gasket 80 in the pressure control device plays a key role. The flow limiting gasket 80 can help stabilize the flow and pressure in the pressure control device so that the pressure control device can work normally. If the flow limiting gasket 80 is not set, all the gas will be drawn away by the vacuum pump 40, and the first pressure controller 30 cannot control the pressure to the set pressure. Figure 2 FIG. 1 is a partial enlarged view of the surface between the wafer and the wafer temperature control base provided according to an embodiment of the present invention. Figure 2 As shown, if the third isolation valve V3 is closed and the gas is not allowed to flow away, after the set pressure is reached between the wafer 10 and the wafer temperature control base 20, due to the uneven surface between the wafer 10 and the wafer temperature control base 20 at the microscopic level, that is, the wafer 10 and the wafer temperature control base 20 cannot be completely isolated from the chamber 50, a small airflow will flow between the wafer 10 and the wafer temperature control base 20, causing the pressure between the wafer 10 and the wafer temperature control base 20 to continue to rise to the same as the pressure in the chamber 50, and the pressure between the wafer 10 and the wafer temperature control base 20 cannot be maintained constant.

[0065] Based on the above reasons, a flow limiting gasket 80 needs to be set in the pipeline that controls the pressure between the wafer 10 and the wafer temperature control base 20 to extract excess gas in the pipeline and maintain the stability of the pipeline that controls the pressure between the wafer 10 and the wafer temperature control base 20. Figure 3 Schematic diagram of the structure of a flow limiting gasket in a pressure control device provided according to an embodiment of the present invention. Figure 1 and Figure 3 As shown, adding a flow-limiting gasket 80 can maintain a certain pressure differential in the pipeline before and after the flow-limiting gasket 80 while allowing some gas to be drawn away by the vacuum pump 40. The working principle of the flow-limiting gasket 80 in the pressure control device is as follows: when gas flows in the pipeline, the local resistance of the flow-limiting gasket 80 causes the gas pressure on one side of the flow-limiting gasket 80 to increase. At the same time, some gas flows through the flow-limiting gasket 80 and out to the pipeline on the other side of the flow-limiting gasket 80. After the gas passes through the flow-limiting gasket 80, energy is lost. This phenomenon is called throttling in thermodynamics.

[0066] Based on the technical solution of the above invention embodiment, Figure 1 Optionally, the aperture parameter of the flow limiting gasket 80 is positively correlated with the gas flow measurement range of the first pressure controller 30 .

[0067] In an embodiment of the present invention, Figure 4 3 is a schematic diagram showing the effect of selecting current limiting gaskets with different apertures on the actual pressure between the wafer and the wafer temperature control base when the set pressure range of the first pressure controller provided by an embodiment of the present invention is 0 to 100 Torr. Figure 5 This is a schematic diagram showing the effect of selecting a 0.3mm aperture current limiting gasket on the actual pressure between the wafer and the wafer temperature control base when the set pressure range of the first pressure controller provided by an embodiment of the present invention is 0 to 100 Torr. Figure 4 and Figure 5 According to the experiment, when the set pressure range of the first pressure controller 30 is 0 to 100Torr, the flow limiting gasket 80 with an aperture of 0.3mm matches the specification parameters of the first pressure controller 30. Therefore, in the embodiment of the present invention, the diameter of the flow limiting gasket 80 is designed to be 0.3mm, the pressure control range of the first pressure controller 30 is 0-100Torr, and the gas flow measurement range is 0-100SCCM. In other optional embodiments of the present invention, if the pressure control range of the first pressure controller 30 changes, or the gas flow measurement range changes, the aperture of the corresponding flow limiting gasket 80 also needs to be redesigned. For example, when the pressure control range of the first pressure controller 30 decreases, or the gas flow measurement range decreases, the aperture of the flow limiting gasket 80 needs to be reduced. Figure 6 Schematic diagram of the relationship between the pressure and gas flow between the wafer and the wafer temperature control base when the pressure control device provided by the embodiment of the present invention is working. Figure 6 As shown, in this embodiment of the present invention, a 0.3mm pore size flow-limiting gasket 80 is used. The pressure between the wafer 10 and the wafer temperature control base 20 is directly proportional to the gas flow rate. The measured flow rate fluctuates less than the ideal flow rate. The first pressure controller 30 has a pressure control range of 0-100 Torr and a gas flow measurement range of 0-100 SCCM.

[0068] Figure 7 This is a flow chart of a pressure control method provided according to an embodiment of the present invention. This embodiment can be applied to control the pressure of the gas filled between the wafer and the wafer temperature control base. The pressure control method can be executed by a pressure control device, which can be implemented in the form of hardware and / or software. Figure 7 As shown, the method includes:

[0069] S110 , controlling the first isolation valve, the second isolation valve, and the third isolation valve to be in an open state according to a preset sequence.

[0070] Figure 8 yes Figure 7 The structural diagram of the pressure control device corresponding to S110. Figure 8 The wafer 10 is placed on the wafer temperature control base 20, and the pressure of the chamber 50 is controlled to the pressure required by the process. The isolation valves are opened in sequence: first, the third isolation valve V3, then the first isolation valve V1, and finally the second isolation valve V2.

[0071] S120, controlling the vacuum pump to adsorb the wafer onto the wafer temperature control base.

[0072] Specifically, refer to Figure 8 The vacuum pump 40 can evacuate the gas between the wafer 10 and the wafer temperature control base 20, so that the gas pressure between the wafer 10 and the wafer temperature control base 20 is less than the pressure on the front of the wafer 10, so that the wafer 10 is adsorbed on the wafer temperature control base 20, so that the narrow gap between the wafer 10 and the wafer temperature control base 20 forms a closed environment.

[0073] S130 , controlling the pressure of the gas introduced between the wafer and the wafer temperature control base to be a first preset pressure through a first pressure controller.

[0074] refer to Figure 8 For example, the first pressure controller 30 is set to a pressure of 30 Torr and begins operation. At this point, a portion of the gas flows through the first pressure controller 30, the first isolation valve V1, and the second isolation valve V2 into the space between the wafer 10 and the wafer temperature control pedestal 20. The remaining portion of the gas is drawn away by the vacuum pump 40 through the third isolation valve V3. This ensures that the gas pressure between the wafer 10 and the wafer temperature control pedestal 20 reaches a first preset pressure and remains constant.

[0075] The technical solution of the embodiment of the present invention sets a pressure control method, opens the first isolation valve, the second isolation valve and the third isolation valve in a preset order, and the residual gas in the pipeline is discharged, thereby improving the purity of the gas entering between the wafer and the wafer temperature control base. When the first isolation valve, the second isolation valve and the third isolation valve are all in the open state, the gas between the wafer and the wafer temperature control base can be evacuated by a vacuum pump, so that the gas pressure between the wafer and the wafer temperature control base is less than the pressure on the front of the wafer, so that the wafer is adsorbed on the wafer temperature control base, so that the narrow gap between the wafer and the wafer temperature control base forms a closed environment. Set the pressure of the first pressure controller and start working. After the gas passes through the first pressure controller, part of the gas enters between the wafer and the wafer temperature control base through the first pressure controller, the first isolation valve and the second isolation valve, and the other part of the gas is drawn away by the vacuum pump through the third isolation valve, so that the gas pressure between the wafer and the wafer temperature control base reaches the first preset pressure and maintains a constant pressure, thereby achieving precise control of the pressure of the gas filled between the wafer and the wafer temperature control base, improving the surface uniformity of the wafer, and improving the thermal conductivity of the wafer and the wafer temperature control base.

[0076] Figure 9 FIG. 1 is a flow chart of another pressure control method according to an embodiment of the present invention. This embodiment is a detailed description of the technical features of the above embodiment. Figure 9 As shown, the pressure control method includes:

[0077] S210: Control the second pressure controller and the fourth isolation valve to be in an open state.

[0078] refer to Figure 8 , controlling the fourth isolation valve V4, the second pressure controller 60 and the vacuum pump 40 to be in the open state.

[0079] S211. Control the chamber to a vacuum state through a vacuum pump.

[0080] S212. Regulate the opening of the fourth isolation valve through the second pressure controller to control the pressure of the chamber to be stable at a second preset pressure; wherein the first preset pressure is less than the second preset pressure.

[0081] refer to Figure 8 The opening of the fourth isolation valve V4 is adjusted by the second pressure controller 60 to adjust the pressure in the chamber 50 so that the pressure in the chamber 50 is maintained at a stable process pressure, such as the second preset pressure. The second preset pressure can be set within the range of 0-100 Torr.

[0082] S213: Control the first isolation valve, the second isolation valve, and the third isolation valve to be in an open state according to a preset sequence.

[0083] S214, controlling the vacuum pump to adsorb the wafer onto the wafer temperature control base.

[0084] S215 , detecting the pressure of the gas between the wafer and the wafer temperature control base.

[0085] refer to Figure 8 After the wafer 10 is adsorbed on the wafer temperature control base 20 , an adsorption test of the wafer 10 is performed to compare the pressure of the gas between the wafer 10 and the wafer temperature control base 20 with the pressure in the chamber 50 .

[0086] S216 , when the difference between the pressure of the gas between the wafer and the wafer temperature control base and the second preset pressure is less than the first preset difference, an alarm is generated.

[0087] refer to Figure 8When the difference between the pressure of the gas between the wafer 10 and the wafer temperature control pedestal 20 and the second preset pressure is less than the first preset difference, it indicates that the wafer 10 is not fully adsorbed, indicating that the wafer 10 or the wafer temperature control pedestal 20 is in an abnormal state, and an alarm is required to remind staff to handle it. For example, the second preset pressure is 50 Torr and the first preset difference is 10 Torr. When the pressure of the gas between the wafer 10 and the wafer temperature control pedestal 20 is 45 Torr, the difference between the pressure of the gas between the wafer 10 and the wafer temperature control pedestal 20 and the second preset pressure is 5 Torr, which is less than 10 Torr. The wafer 10 is not fully adsorbed and an alarm is required to remind staff to handle it.

[0088] S217 , controlling the pressure of the gas introduced between the wafer and the wafer temperature control base to be a first preset pressure through a first pressure controller.

[0089] refer to Figure 10 , close the second isolation valve V2, set the pressure of the first pressure controller 30 to the first preset pressure, and control the pressure of the gas between the wafer 10 and the wafer temperature control base 20 through the first pressure controller 30 to be stable at the first preset pressure.

[0090] S218. Detect the pressure of the gas between the wafer and the wafer temperature control base.

[0091] refer to Figure 6 The second isolation valve V2 is opened, and gas flows through the first pressure controller 30, the first isolation valve V1, and the second isolation valve V2 into the space between the wafer 10 and the wafer temperature-controlled pedestal 20. After the pressure of the gas between the wafer 10 and the wafer temperature-controlled pedestal 20 stabilizes at the first preset pressure and the surface temperature of the wafer 10 stabilizes, the chemical vapor deposition process is performed. During the chemical vapor deposition process, the pressure of the gas between the wafer 10 and the wafer temperature-controlled pedestal 20 is monitored.

[0092] S219 , when the difference between the pressure of the gas between the wafer and the wafer temperature control base and the first preset pressure is greater than the second preset difference, an alarm is generated.

[0093] refer to Figure 8 If the pressure of the gas between the wafer 10 and the wafer temperature control pedestal 20 deviates, an alarm is triggered. For example, the second preset pressure in the chamber 50 is set to 50 Torr, and the first preset pressure is set to 30 Torr. The pressure of the gas between the wafer 10 and the wafer temperature control pedestal 20 is monitored. When the pressure of the gas between the wafer 10 and the wafer temperature control pedestal 20 is greater than 35 Torr or less than 25 Torr, it means that the difference between the pressure of the gas between the wafer 10 and the wafer temperature control pedestal 20 and the first preset pressure is greater than the second preset difference, indicating that the pressure of the gas between the wafer 10 and the wafer temperature control pedestal 20 has deviated, and an alarm is triggered to remind staff to handle it.

[0094] After the deposition process of the wafer 10 is completed, the pressure of the first pressure controller 30 is set to the pressure of the chamber 50 so that the pressure between the wafer 10 and the wafer temperature control base 20 is close to the pressure of the chamber 50, and the wafer is released for the first time.

[0095] refer to Figure 11 The third and fourth isolation valves V3 and V4 are closed, the fifth isolation valve V5 is opened, and the first pressure controller 30 is stopped. The chamber 50 is connected to the wafer 10 and the wafer temperature control pedestal 20, ensuring that the pressure between the wafer 10 and the wafer temperature control pedestal 20 is exactly the same as the pressure in the chamber 50. The wafer 10 is released a second time, and now the wafer 10 is completely released. The processing of the wafer 10 is completed, and the wafer 10 is removed from the wafer temperature control pedestal 20.

[0096] Figure 12 FIG. 1 is a flow chart of another pressure control method provided according to an embodiment of the present invention. Figure 12 As shown, the pressure control method includes:

[0097] S310, transfer the wafer to the wafer temperature control base; S311, control the chamber pressure; S312, open the first isolation valve, the second isolation valve and the third isolation valve, and adsorb the wafer on the wafer temperature control base; S313, wafer adsorption detection; if there is an abnormality, execute S320, alarm, and manual processing; if there is no abnormality, execute S314, set the pressure between the wafer and the wafer temperature control base; S315, control the pressure between the wafer and the wafer temperature control base to reach the preset pressure; S316, pressure detection between the wafer and the wafer temperature control base; if there is an abnormality, execute S320, alarm, and manual processing; if there is no abnormality, execute S317, release the wafer for the first time; S318, release the wafer for the second time; S319, end.

[0098] The pressure control device provided in the embodiment of the present invention can execute the pressure control method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0099] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present invention can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved. This is not limited herein.

[0100] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A pressure control device, characterized in that: Used to control the gas pressure between the wafer and the wafer temperature control base; the pressure control device includes: a first pressure controller, a first isolation valve, a second isolation valve, a third isolation valve and a vacuum pump; One end of the first isolation valve is connected to the first pressure controller, and the other end of the first isolation valve is connected to one end of the second isolation valve and one end of the third isolation valve respectively; the other end of the second isolation valve is connected to the wafer and the wafer temperature control base; the other end of the third isolation valve is connected to the vacuum pump; The vacuum pump is used to adsorb the wafer on the wafer temperature control base when the first isolation valve, the second isolation valve and the third isolation valve are in an open state according to a preset sequence; The first pressure controller is used to control the pressure of the gas between the wafer and the wafer temperature control pedestal to be a first preset pressure; wherein a portion of the gas enters between the wafer and the wafer temperature control pedestal through the first pressure controller, the first isolation valve, and the second isolation valve, and another portion of the gas is extracted by the vacuum pump through the third isolation valve; The pressure control device further comprises: a flow limiting gasket; the flow limiting gasket is arranged between the first isolation valve and the third isolation valve; The flow limiting gasket is used to control the amount of gas drawn away by the vacuum pump.

2. The pressure control device according to claim 1, characterized in that Also includes: A chamber vacuum system comprising a chamber, a fourth isolation valve, and a second pressure controller; the wafer and the wafer temperature control base are placed in the chamber, and the chamber is used to perform a thin film deposition process on the wafer; the fourth isolation valve is connected between the chamber and the second pressure controller; and the second pressure controller is connected between the fourth isolation valve and the vacuum pump; The vacuum pump is further configured to control the chamber to reach a vacuum state when the second pressure controller and the fourth isolation valve are in an open state; The second pressure controller is used to adjust the opening of the fourth isolation valve to control the pressure of the chamber to be stable at a second preset pressure; wherein the first preset pressure is less than the second preset pressure.

3. The pressure control device according to claim 2, characterized in that: Also includes: Fifth isolation valve; One end of the fifth isolation valve is connected to the chamber, and the other end of the fifth isolation valve is connected to the first isolation valve and the third isolation valve; The fifth isolation valve is used to communicate with the second isolation valve when the third isolation valve is in a closed state and the first pressure controller is in a stopped state, so that the pressure between the wafer and the wafer temperature control base is the same as the pressure in the chamber.

4. The pressure control device according to claim 2, characterized in that: Also includes: Monitoring unit; The monitoring unit is used to alarm when the difference between the pressure of the gas between the wafer and the wafer temperature control base and the second preset pressure is less than the first preset difference; and / or, the monitoring unit is used to alarm when the difference between the pressure of the gas between the wafer and the wafer temperature control base and the first preset pressure is greater than the second preset difference.

5. The pressure control device according to claim 1, wherein: The aperture parameter selection of the flow limiting gasket is positively correlated with the gas flow measurement range of the first pressure controller.

6. A pressure control method, characterized in that: The pressure control device according to any one of claims 1 to 5; the pressure control method comprising: Control the first isolation valve, the second isolation valve and the third isolation valve to be in an open state according to a preset sequence; Controlling the vacuum pump to adsorb the wafer onto the wafer temperature control base; The pressure of the gas introduced between the wafer and the wafer temperature control base is controlled by a first pressure controller to be a first preset pressure.

7. The pressure control method according to claim 6, characterized in that: Before controlling the first isolation valve, the second isolation valve, and the third isolation valve to be in an open state in a preset order, the method further includes: Control the second pressure controller and the fourth isolation valve to be in an open state; Controlling the chamber to a vacuum state by the vacuum pump; The opening of the fourth isolation valve is adjusted by the second pressure controller to control the pressure of the chamber to be stable at a second preset pressure; wherein the first preset pressure is less than the second preset pressure.

8. The pressure control method according to claim 7, characterized in that: After the vacuum pump is controlled to adsorb the wafer onto the wafer temperature control base, the method further includes: detecting the pressure of the gas between the wafer and the wafer temperature control base; An alarm is triggered when the difference between the pressure of the gas between the wafer and the wafer temperature control base and the second preset pressure is less than the first preset difference.

9. The pressure control method according to claim 7, characterized in that: After controlling the pressure of the gas between the wafer and the wafer temperature control base to be a first preset pressure by the first pressure controller, the method further includes: detecting the pressure of the gas between the wafer and the wafer temperature control base; An alarm is triggered when the difference between the pressure of the gas between the wafer and the wafer temperature control base and the first preset pressure is greater than a second preset difference.

Images