Method for reducing shadow ring offset probability

Abstract

The embodiment of the invention provides a method for reducing the offset probability of a shadow ring, and the method comprises the steps: pumping the air pressure in a reaction chamber to a low-pressure state through an air pumping device after a wafer is placed on a wafer carrying platform; after the wafer carrying table is lifted to abut against a shadow ring, the wafer carrying table and the shadow ring are moved to the chemical vapor deposition process position, and the chemical vapor deposition process is carried out; after the chemical vapor deposition process is completed, the air pressure in the reaction chamber is pumped to the low-pressure state through the air pumping device; and driving the shadow ring to fall back through the descending of the wafer carrier until the ear part of the shadow ring is placed in the positioning groove of the air extractor. By adopting the technical scheme, the offset probability of the shadow ring can be reduced.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of semiconductor manufacturing technology, and in particular to a method for reducing the probability of shadow ring deviation. Background Art

[0002] During the chemical vapor deposition process, chemical vapor deposition equipment needs to use a shadow ring to press the edge of the wafer within a range of about two millimeters to prevent the deposition at the edge of the wafer from peeling off and generating particles that affect the reaction chamber environment. After the wafer carrier carrying the wafer is raised to a certain height, it contacts the shadow ring and makes it press the edge of the wafer. Because the wafer is mechanically lifted to contact the shadow ring, the shadow ring is easily affected by the airflow in the chamber, generating an air cushion effect and displacement, resulting in a shift in the position of the wafer edge, affecting the uniformity of the chemical vapor deposition film and causing peeling defects at the edge of the wafer.

[0003] Therefore, how to provide a technical solution to solve the problem of shadow ring offset has become a technical problem that needs to be solved urgently. Summary of the Invention

[0004] In view of this, an embodiment of the present invention provides a method for reducing the probability of shadow ring shift, which can effectively reduce the probability of shadow ring shift.

[0005] To solve the above technical problems, an embodiment of the present invention provides a method for reducing the probability of shadow ring deviation, including: after the wafer is placed on the wafer carrier, the air pressure in the reaction chamber is pumped to a low-pressure state by a vacuum device; after the wafer carrier is raised to contact the shadow ring, the wafer carrier and the shadow ring are moved to the chemical vapor deposition process position to perform a chemical vapor deposition process; after the chemical vapor deposition process is completed, the air pressure in the reaction chamber is pumped to the low-pressure state by the vacuum device; by lowering the wafer carrier, the shadow ring is driven to fall back until the ear of the shadow ring is placed in the positioning groove of the vacuum device.

[0006] Optionally, placing the wafer on a wafer stage includes: controlling the wafer stage to descend to a position for supporting the wafer through a motor; and placing the wafer on the wafer stage through a gap between the wafer stage and the exhaust device through a robotic arm.

[0007] Optionally, the exhaust device is annular and is arranged around the wafer carrier. The exhaust device includes: one or more positioning grooves, which are recessed in the side wall of the exhaust device, and the positioning groove has a semi-surrounding side wall and a bottom; and an exhaust hole penetrated through the exhaust device, which is used to extract the gas in the reaction chamber.

[0008] Optionally, a shadow ring is provided above the wafer carrier, and a plurality of ears are evenly arranged around the shadow ring; wherein, the side wall of the vacuum device has an inwardly recessed positioning groove corresponding one-to-one to the ears, and the size of the positioning groove is larger than the size of the ears. When the installation is completed, the ears extend into the positioning groove one-to-one, and the bottom of the positioning groove has a one-to-one step portion supporting the ears.

[0009] Optionally, the air suction hole is coupled to a vacuum pump for providing negative pressure for the air suction hole.

[0010] Optionally, after the wafer stage is raised to the position where it contacts the shadow ring, the wafer stage and the shadow ring are moved to the chemical vapor deposition process position to perform a chemical vapor deposition process, including: when the air pressure in the reaction chamber is pumped to the low pressure state, the exhaust device is closed; the wafer stage is driven by a motor to carry the wafer up until the shadow ring placement position contacts the shadow ring; the shadow ring is carried by the edge of the wafer and driven to the position where the chemical vapor deposition process is performed on the wafer.

[0011] Optionally, the chemical vapor deposition process sets different process durations according to different processes through the menu of the chemical vapor deposition machine; after the chemical vapor deposition process is completed, the reaction gas flowing into the reaction chamber during the chemical vapor deposition process is extracted through the exhaust device and pumped to a low pressure state.

[0012] Optionally, the wafer stage has lifting pins evenly arranged around the center of the wafer stage for receiving and supporting the wafer.

[0013] Optionally, the lifting pins rise from the wafer carrier to receive the wafer; the wafer carrier rises to a position flush with the lifting pins to complete carrying the wafer.

[0014] Optionally, the low pressure state, i.e., the atmospheric pressure range is [0.1 torr, 10 torr].

[0015] Compared with the prior art, the technical solution of the embodiment of the present invention has the following advantages:

[0016] In a method for reducing the probability of shadow ring shifting provided by an embodiment of the present invention, after a wafer is placed on a wafer carrier, the air pressure in the reaction chamber is first pumped down to a low pressure state by an exhaust device, the wafer carrier is then raised until it contacts the shadow ring, and then the wafer carrier and the shadow ring are moved to a chemical vapor deposition process position; after the chemical vapor deposition process is completed, the air pressure in the reaction chamber is first pumped down to the low pressure state by the exhaust device, and then the wafer carrier is lowered, driving the shadow ring back down until the ears of the shadow ring are placed in the positioning grooves of the exhaust device. Since the wafer carrier and the shadow ring are both in a low pressure state during the rising and / or descending movement, the wafer carrier and the shadow ring are not affected by the airflow, resulting in an air cushion effect. Therefore, the probability of shadow ring shifting can be effectively reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the invention of this specification, the following briefly introduces the drawings required for use in the embodiments of the invention of this specification or the description of the prior art. Obviously, the drawings described below are only some embodiments of this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0018] Figure 1 A schematic flow chart of a method for reducing the probability of shadow ring offset according to an embodiment of the present invention is shown;

[0019] Figure 2 A schematic diagram of a chemical vapor deposition device according to an embodiment of the present invention is shown;

[0020] Figure 3 A schematic diagram of a process scenario in which a wafer stage is moved until it collides with a shadow ring is shown in an embodiment of the present invention;

[0021] Figure 4 A schematic diagram of a process scenario in which a wafer stage and a shadow ring are moved in an embodiment of the present invention is shown;

[0022] Figure 5 A schematic diagram of a process scene when a moving wafer stage and a shadow ring process are completed in an embodiment of the present invention is shown;

[0023] Figure 6 A schematic diagram of a process scenario in which a wafer stage and a shadow ring are moved until the wafer stage is away from the shadow ring is shown in an embodiment of the present invention;

[0024] Figure 7 A schematic top view of a chemical vapor deposition apparatus according to an embodiment of the present invention is shown;

[0025] Figure 8A cross-sectional schematic diagram of an air extraction device according to an embodiment of the present invention is shown;

[0026] Figure 9 Another cross-sectional schematic diagram of an air extraction device in an embodiment of the present invention is shown.

[0027] Description of reference numerals:

[0028] Wafer stage 200 , lift pins 201 , exhaust device 210 , positioning groove 211 , exhaust hole 212 , step portion 213 , shadow ring 220 , ear portion 221 ;

[0029] The wafer stage rises in the direction F1 and descends in the direction F2. DETAILED DESCRIPTION

[0030] The technical solutions of the present invention are described in detail below in conjunction with specific embodiments and the accompanying drawings. The embodiments described herein are specific embodiments of the present invention and are used to illustrate the concept of the present invention. These descriptions are all illustrative and exemplary and should not be construed as limiting the embodiments of the present invention and the scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art can also adopt obvious other technical solutions based on the contents disclosed in the claims of this application and the specification thereof, including technical solutions that adopt any obvious replacements and modifications to the embodiments described herein.

[0031] It should be noted that the drawings in this embodiment are schematic diagrams to assist in illustrating the concept of the present invention and schematically illustrate the shapes of the various components and their interrelationships. It should be understood that in order to clearly illustrate the structure of the various components of the present invention, the drawings are not drawn to the same scale, and the same reference numerals are used to represent the same parts in the drawings.

[0032] As described in the background technology, chemical vapor deposition equipment needs to use a shadow ring to press the edge of the wafer within a range of about two millimeters during the chemical vapor deposition process to prevent the deposition at the edge of the wafer from peeling off and generating particles that affect the reaction chamber environment. After the wafer carrier carrying the wafer is raised to a certain height, it contacts the shadow ring and makes the shadow ring press the edge of the wafer. Since the shadow ring is easily affected by the airflow in the cavity, it produces an air cushion effect and is displaced, resulting in a shift in the position of the edge of the wafer being pressed, affecting the uniformity of the chemical vapor deposition film and producing peeling defects at the edge of the wafer.

[0033] To solve the above technical problems, an embodiment of the present invention provides a method for reducing the probability of shadow ring deviation. After the wafer is placed on the wafer carrier, the air pressure in the reaction chamber is first pumped to a low pressure state by an exhaust device, and then the wafer carrier is raised until it contacts the shadow ring. Then, the wafer carrier and the shadow ring are moved to the chemical vapor deposition process position. After the chemical vapor deposition process is completed, the air pressure in the reaction chamber is first pumped to the low pressure state by the exhaust device, and then the wafer carrier is lowered, driving the shadow ring to fall back until the ears of the shadow ring are placed in the positioning grooves of the exhaust device. Since the wafer carrier and the shadow ring are in a low pressure state during the upward and / or downward movement, the wafer carrier and the shadow ring are not affected by the airflow, and an air cushion effect occurs. Therefore, the probability of shadow ring deviation can be effectively reduced.

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is described clearly and completely below with reference to the accompanying drawings.

[0035] See also Figure 1 , Figure 1 A flow chart of a method for reducing the probability of shadow ring offset according to an embodiment of the present invention is shown. The method may perform the following steps S10 to S13, each of which is described below.

[0036] In step S10 , after the wafer is placed on the wafer stage, the air pressure in the reaction chamber is pumped down to a low pressure state by a pumping device.

[0037] Combined with reference Figure 1 、 Figure 2 and Figure 7 , Figure 2 A schematic diagram of a chemical vapor deposition device according to an embodiment of the present invention is shown. Figure 7 A schematic top view of a chemical vapor deposition device according to an embodiment of the present invention is shown.

[0038] Specifically, the wafer stage 200 is coupled to a motor and can be driven by the motor to move up and down in a direction perpendicular to the carrying surface of the wafer stage 200 , so that the wafer stage 200 can move up or down while carrying the wafer.

[0039] Wherein, the motor is a servo motor, which can control the lifting speed and has very accurate position accuracy, and converts the voltage signal into torque and speed to drive the control object. The rotor speed of the servo motor is controlled by the input signal and can respond quickly. In the automatic control system, it is used as an actuator and has the characteristics of small electromechanical time constant and high linearity. It can convert the received electrical signal into angular displacement or angular velocity output on the motor shaft. The servo motor is divided into two categories: DC and AC servo motors. Its main characteristics are that there is no self-rotation when the signal voltage is zero, and the speed decreases at a uniform speed as the torque increases. People in this field can make their own choices according to their own needs, and there is no restriction on the type of the motor.

[0040] In addition, placing the wafer on the wafer carrier 200 includes: controlling the wafer carrier 200 to descend to a position for carrying the wafer through a motor; and placing the wafer on the wafer carrier 200 through a gap between the wafer carrier 200 and the exhaust device 210 through a robotic arm.

[0041] Specifically, the wafer stage 200 has lift pins 201 evenly spaced around its center for receiving and supporting the wafer. Driven by the motor, the wafer stage 200 gradually descends to its lowest position, after which the lift pins 201, driven by the motor, rise within the wafer stage 200 to receive the wafer. The robotic arm places the wafer on the lift pins 201 through the gap between the wafer stage 200 and the vacuum device 210. The wafer stage 200 then rises until it is flush with the lift pins 201, completing the wafer loading process.

[0042] In a specific embodiment, the number of the lifting pins 201 is three.

[0043] In some embodiments, a support surface in contact with the wafer is provided on the top of each lifting pin 201 , and the support surface is preferably a flat surface or a slightly convex arc structure to increase the contact area with the wafer and reduce local stress concentration.

[0044] The exhaust device 210 is annular and is disposed around the wafer stage 200. The exhaust device 210 has an exhaust hole 212 passing through the exhaust device 210 for extracting gas from the reaction chamber.

[0045] The inner diameter of the vacuum device 210 is larger than the diameter of the wafer carrier 200, so that the wafer carrier 200 carries the wafer and lifts it within the inner diameter of the vacuum device 210 without colliding with the vacuum device 210, thereby reducing the probability of damage to devices and / or equipment.

[0046] The air pumping hole 212 is coupled to a vacuum pump to provide negative pressure for the air pumping hole 212 by sucking gas.

[0047] Specifically, after the wafer stage 200 completes carrying the wafer, the wafer stage 200 stops moving and remains in its current position. The vacuum pump is driven through the exhaust hole 212 to extract the gas in the reaction chamber, that is, the air pressure in the reaction chamber is pumped to a low pressure state, and the low pressure state, that is, the atmospheric pressure range is [0.1 torr, 10 torr]. In this embodiment, the air pressure is pumped to 5 torr. After the air pressure in the reaction chamber is pumped to a low pressure state, the wafer stage 200 is driven to rise.

[0048] Combined with reference Figure 3 and Figure 4 , Figure 3 A schematic diagram of a process scenario in which a wafer carrier is moved until it collides with a shadow ring is shown in an embodiment of the present invention. Figure 4 A schematic diagram of a process scenario in which a wafer carrier and a shadow ring are moved in an embodiment of the present invention is shown. Figure 3 and Figure 4 Schematic diagrams of process scenes in which the wafer stage 200 is raised until it hits the shadow ring 220 and the wafer stage 200 is raised to a chemical vapor deposition position after hitting the shadow ring 220 in accordance with an embodiment of the present invention are shown.

[0049] Wherein, F1 is the rising direction of the wafer stage 200 .

[0050] In step S11 , after the wafer stage is raised to contact the shadow ring, the wafer stage and the shadow ring are moved to a chemical vapor deposition process position to perform a chemical vapor deposition process.

[0051] Specifically, during the process of starting to raise the wafer stage 200 until the wafer stage 200 reaches the position of the shadow ring 220, the reaction chamber in which the wafer stage 200 and the shadow ring 220 are located is in the low-pressure state. The wafer stage 200 abuts against the shadow ring 220 and carries and drives the shadow ring 220 to the chemical vapor deposition process position to perform the chemical vapor deposition process.

[0052] In other words, a shadow ring 220 is disposed above the wafer stage 200, and a plurality of ears 221 are evenly arranged around the shadow ring 220. The main body of the shadow ring 220 is an annular structure, and is preferably made of a high-temperature resistant, low thermal expansion coefficient material, such as graphite, silicon carbide, or ceramic.

[0053] During the thin film deposition process, the deposition process is irregular, and there is a possibility that the film will be deposited on the side of the silicon wafer edge. In the subsequent photolithography and etching processes, there is a risk of the carbon film at the edge peeling off, thus affecting device performance. Therefore, the shadow ring 220 is used to cover the edge of the silicon wafer (approximately 3mm to 5mm). The film originally deposited on the edge will be deposited on the shadow ring 220, thereby preventing deposition at the edge of the silicon wafer.

[0054] The air extraction device 210 includes: one or more positioning grooves 211 recessed in the side wall of the air extraction device 210 , and the positioning groove 211 has a semi-surrounding side wall and a bottom.

[0055] The positioning grooves 211 correspond one-to-one to the ears 221 of the shadow ring 220 .

[0056] See also Figure 8 and Figure 9 , Figure 8 A cross-sectional schematic diagram of an air extraction device in an embodiment of the present invention is shown. Figure 9 Another cross-sectional schematic diagram of an air extraction device according to an embodiment of the present invention is shown. Figure 8 for Figure 7 A schematic cross-sectional view of the middle air extraction device 210 cut along A1-A2, Figure 9 for Figure 7 A schematic cross-sectional view of the middle air extraction device 210 cut along line B1-B2.

[0057] Specifically, the side wall of the exhaust device 210 has an inwardly recessed positioning groove 211 corresponding one-to-one to the ear 221, and the size of the positioning groove 211 is larger than the size of the ear 221. When the installation is completed, the ears 221 extend into the positioning groove 211 one-to-one, and the bottom of the positioning groove 211 has a one-to-one step portion 213 supporting the ear 221.

[0058] The size of the positioning groove 211 is slightly larger than the size of the ear 221 so as to provide sufficient clearance for the ear 221 during installation, thereby avoiding damage to the exhaust device 210 and / or the ear 221 due to collision during installation.

[0059] It should be noted that the above example does not limit the number of the positioning grooves 211 and the shadow rings 220. In a specific embodiment, the number of the positioning grooves 211 and the shadow rings 220 is four. In addition to the four shown in the above example, the number of the positioning grooves 211 and the shadow rings 220 can also be multiple, such as two, three, or five.

[0060] In addition, after the wafer carrier 200 is raised until it contacts the shadow ring 220, the wafer carrier 200 and the shadow ring 220 are moved to the chemical vapor deposition process position to perform a chemical vapor deposition process, including: when the gas pressure in the reaction chamber is pumped to the low pressure state, closing the exhaust device 210.

[0061] In some embodiments, some chemical vapor deposition equipment does not have the conditions to maintain a stable gas pressure in the reaction chamber. When the wafer carrier 200 rises to contact the shadow ring 220, the vacuum pump can be kept turned on to provide a stable low-pressure process environment.

[0062] The wafer stage 200 is driven by a motor to carry the wafer and rise, and contacts the shadow ring 220 at the position where the shadow ring 220 is placed.

[0063] The shadow ring 220 is placed in the positioning groove 211 of the air extraction device 210 through the ear portion 221 .

[0064] The shadow ring 220 is supported by the edge of the wafer and is driven to rise to a position where a chemical vapor deposition process is performed on the wafer.

[0065] In a specific embodiment, the shadow ring 220 is supported against the edge of the wafer and driven to rise to a position for performing a chemical vapor deposition process on the wafer. During this process, the wafer stage 200 and the shadow ring 220 are both in the low-pressure state.

[0066] After the wafer stage 200 carries the wafer and rises against the shadow ring 220 to the position for the chemical vapor deposition process, the exhaust device 210 is closed to avoid affecting the subsequent chemical vapor deposition process.

[0067] In some embodiments, whether the exhaust device 210 is closed or not is related to the content of the subsequent process. If a low pressure or vacuum state is still required in the subsequent process, whether the exhaust device 210 is closed or not is determined according to different process requirements.

[0068] In some embodiments, the wafer stage 200 has a heating function, meaning it acts as a heating platform, providing precise temperature control for the wafer, providing energy for chemical reactions, and regulating deposition rates and film properties. Through multi-zone heating and thermal design, the wafer surface temperature is kept consistent, creating ideal conditions for the reaction gases to react on the wafer surface.

[0069] In some embodiments, the exhaust device 210 arranged around the wafer carrier 200 is used to exhaust the reaction gas, by-products and unreacted gas from the exhaust hole 212 during chemical vapor deposition (CVD) or other thin film deposition processes to maintain the gas flow uniformity and pressure stability in the chamber, thereby ensuring the uniformity of thin film deposition and process repeatability.

[0070] Combined with reference Figure 5 and Figure 6 , Figure 5 A schematic diagram of a process scene when a moving wafer carrier and a shadow ring process are completed in an embodiment of the present invention is shown. Figure 6 A schematic diagram of a process scenario in which a wafer carrier and a shadow ring are moved until the wafer carrier is away from the shadow ring is shown in an embodiment of the present invention. Figure 5 and Figure 6 A schematic diagram of a process scene in which the wafer stage 200 is lowered until the shadow ring 220 falls into the positioning groove 211 and the wafer stage 200 is moved away from the shadow ring 220 in an embodiment of the present invention is shown.

[0071] Wherein, F2 is the descending direction of the wafer stage 200 .

[0072] In step S12 , after the chemical vapor deposition process is completed, the gas pressure in the reaction chamber is pumped down to the low pressure state by the gas pumping device.

[0073] Specifically, after the chemical vapor deposition process is completed, the wafer stage 200 stops moving and remains in the current position, and the vacuum pump is driven through the exhaust hole 212 to extract the gas in the reaction chamber, that is, to extract the reaction gas generated by the chemical vapor deposition process in the reaction chamber, and to reduce the air pressure to a low pressure state. The low pressure state, i.e., the atmospheric pressure range is [0.1 torr, 10 torr]. In this embodiment, the air pressure is reduced to 5 torr. After the air pressure in the reaction chamber is reduced to a low pressure state, the wafer stage 200 is driven to descend.

[0074] The chemical vapor deposition process is set to different process times according to the menu of the chemical vapor deposition machine. After the chemical vapor deposition process is completed, the reaction gas flowing into the reaction chamber during the chemical vapor deposition process is extracted by the exhaust device 210 and pumped to a low pressure state.

[0075] In step S13, the wafer stage is lowered to drive the shadow ring to fall back until the ears of the shadow ring are placed in the positioning grooves of the exhaust device.

[0076] Specifically, the exhaust device 210 extracts the reaction gases flowing into the reaction chamber during the chemical vapor deposition process and pumps them down to a low pressure. Driven by the motor, the wafer stage 200, carrying the wafer and the shadow ring 220 covering the wafer edge, slowly descends. The stage descends to the position where the exhaust device 210 supports the shadow ring 220, i.e., the ears 221 of the shadow ring 220 fall into the stepped portion 213 supporting the ears 221.

[0077] The wafer stage 200 carrying the wafer and the shadow ring 220 covering the edge of the wafer is in the low-pressure state in the reaction chamber during the descending process.

[0078] After the ears 221 of the shadow ring 220 are placed in the positioning grooves 211, the wafer stage 200, driven by the motor, gradually descends to its lowest position. The motor then drives the lift pins 201 to rise within the wafer stage 200, carrying and supporting the wafer as it ascends to the wafer removal position. Because the lift pins 201 occupy a relatively small area, the robotic arm removes the wafer placed on the lift pins 201 from the gap between the wafer stage 200 and the vacuum device 210. The lift pins 201 then descend to a position flush with the wafer stage 200.

[0079] It can be understood that the above describes multiple embodiments of the method for reducing the probability of shadow ring offset. The various optional methods introduced in each embodiment can be combined and cross-referenced with each other without conflict, thereby extending a variety of possible embodiments, which can all be considered as embodiments disclosed and open to the public by the present invention.

[0080] It should be understood that the term "and / or" as used herein simply describes an association between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " as used herein indicates that the related objects are in an "or" relationship.

[0081] The term "plurality" used in the embodiments of the present application refers to two or more.

[0082] The first, second, etc. descriptions appearing in the embodiments of this application are only for illustration and distinction of the description objects. There is no order, nor does it indicate any special limitation on the number of devices in the embodiments of this application, and cannot constitute any limitation on the embodiments of this application.

[0083] It should be noted that the serial numbers of the steps in this embodiment do not limit the execution order of the steps.

[0084] Although the embodiments of the present invention are disclosed above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A method for reducing the probability of shadow ring offset, characterized in that: include: After the wafer is placed on the wafer carrier, the air pressure in the reaction chamber is pumped down to a low pressure state through the exhaust device; After the wafer stage is raised until it contacts the shadow ring, the wafer stage and the shadow ring are moved to a chemical vapor deposition process position to perform a chemical vapor deposition process; After the chemical vapor deposition process is completed, the gas pressure in the reaction chamber is pumped down to the low pressure state by the gas pumping device; The wafer stage is lowered to drive the shadow ring to fall back until the ears of the shadow ring are placed in the positioning grooves of the air extraction device.

2. The method according to claim 1, characterized in that Placing the wafer on a wafer stage, comprising: Controlling the wafer stage to descend to a position for carrying the wafer by a motor; The wafer is placed on the wafer carrier through a gap between the wafer carrier and the air extraction device by a robotic arm.

3. The method according to claim 1, characterized in that The exhaust device is annular and is arranged around the wafer carrier. The exhaust device includes: One or more positioning grooves are recessed in the side wall of the air extraction device, and the positioning grooves have a semi-surrounding side wall and a bottom; The gas extraction hole is provided on the gas extraction device and is used to extract the gas in the reaction chamber.

4. The method according to claim 3, characterized in that A shadow ring is provided above the wafer stage, and a plurality of ears are evenly arranged around the shadow ring; In which, the side wall of the exhaust device has an inwardly recessed positioning groove corresponding one-to-one to the ear, and the size of the positioning groove is larger than the size of the ear. When the installation is completed, the ears extend into the positioning groove one-to-one, and the bottom of the positioning groove has a one-to-one step portion supporting the ear.

5. The method according to claim 3, characterized in that The air suction hole is coupled to a vacuum pump for providing negative pressure for the air suction hole.

6. The method according to claim 1, characterized in that After the wafer stage is raised to contact the shadow ring, the wafer stage and the shadow ring are moved to a chemical vapor deposition process position to perform a chemical vapor deposition process, including: When the gas pressure in the reaction chamber is pumped to the low pressure state, closing the gas pumping device; The wafer stage is driven by a motor to carry the wafer upward until the shadow ring is placed at a position that contacts the shadow ring; The shadow ring is supported by the edge of the wafer and is driven to a position where a chemical vapor deposition process is performed on the wafer.

7. The method according to claim 1, characterized in that The chemical vapor deposition process uses the menu of the chemical vapor deposition machine to set different process times according to different processes; After the chemical vapor deposition process is completed, the reaction gas flowing into the reaction chamber during the chemical vapor deposition process is extracted by the gas extraction device and is extracted to a low pressure state.

8. The method according to claim 1, characterized in that The wafer carrier is provided with lifting pins evenly arranged around the center of the wafer carrier for receiving and carrying the wafer.

9. The method according to claim 8, characterized in that Lift pins rise from the wafer carrier to receive the wafer; The wafer carrier rises to a position flush with the lifting pins, completing the process of carrying the wafer.

10. The method according to claim 1, characterized in that The low pressure state, i.e., the atmospheric pressure range is [0.1 torr, 10 torr].

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