A positive film system and a method of using the same

Abstract

A positive film system and a method for using the system, comprising a positive film machine, a mechanical hand (7) and a control system, the positive film machine has a platform, which can translate along the X axis and rotate around the Z axis; the platform is fixed with a suction cup (905); a slide holder (813) is arranged in a substantially U shape; the suction cup (905) is located in the U-shaped opening of the slide holder (813), and the slide holder (813) can move up and down relative to the suction cup (905) between a position higher than the upper surface of the suction cup by a certain distance and a position lower than the upper surface of the suction cup by a certain distance; the mechanical hand (7) has a negative pressure suction port, which can fix an epitaxial wafer (6), transport the epitaxial wafer (6) from an initial position to the slide holder (813), and take away the epitaxial wafer (6) after the positive film is finished; the sensor on the control system can sense the position state of the epitaxial wafer (6) on the suction cup (905); the positive film is realized by controlling the displacement of the mechanical hand (7) in the Y axis direction instead of the Y direction translation movement of the positive film machine.

Description

Technical Field

[0001] This invention relates to an epitaxial wafer positive film system and a method for positive film production using the system. Background Technology

[0002] With the rapid development of the LED and other semiconductor industries, the demand for automated equipment is constantly increasing, the requirements for testing are becoming more stringent, and the positioning accuracy requirements for epitaxial wafers are also rising. Generally, in the epitaxial wafer fabrication process, to facilitate subsequent cutting and testing processes for material positioning or to simultaneously mark the crystal growth orientation, a step called "Flat / Notch Grinning" is performed after the substrate ingot is made. This involves cutting a small flat surface, called a Flat, along the axial direction on the cylindrical surface of the ingot. For ingots with a diameter of less than 200mm, this is called a Flat; for ingots with a diameter of 200mm or more, to reduce waste, only a small arc groove, called a Notch, is machined. Therefore, epitaxial wafers are generally not perfectly circular, but rather have a small flat edge (also called a Flat) or a small notch (also called a Notch). Because epitaxial wafers need to be frequently moved between the stage and the wafer cassette during the manufacturing process, the position of the epitaxial wafer may shift when it is taken out of the wafer cassette. This can lead to problems such as inaccurate positioning and inconsistent orientation of the flat edge or notch when the epitaxial wafer is moved onto the stage. Therefore, in some processes, it is necessary to correct the position and orientation of the epitaxial wafer, that is, to adjust the center coordinates of the epitaxial wafer and the orientation of the flat edge or notch.

[0003] In existing technologies, epitaxial wafer edge-finding positive wafer machines have four degrees of freedom, as detailed in the appendix. Figure 1 The invention patent CN104979258A discloses a wafer alignment system (i.e., a positive wafer builder for epitaxial wafers). This system includes: a motion platform capable of translation around the X, Y, and Z axes and rotation around the Z-axis; a wafer chuck supported on the motion platform for carrying the wafer; at least four cameras, two of which are positioned at two opposite corners of the wafer with defined positioning notches to obtain target feature images of each corner, and other cameras are positioned at the remaining edges of the wafer to obtain target feature images of the remaining edges, wherein all cameras have a sufficiently large field of view to cover wafer transfer errors; a multi-channel image acquisition card coupled to each camera to acquire the target feature images of the corners and the remaining edges; and a processor coupled to the multi-channel image acquisition card to compare the target feature images of the corners and the remaining edges with pre-stored ideal feature images and calculate the wafer transfer error.

[0004] This invention patent also relates to a wafer alignment method, comprising: transferring a wafer to a wafer carrier chuck supported on a motion platform within a maximum wafer transfer error range and moving the motion platform to position the wafer at the common focal point of all cameras, wherein the number of cameras is at least four, all cameras are coupled to a multi-channel image acquisition card, and each camera has a sufficiently large field of view to cover the maximum wafer transfer error; two of the cameras are respectively aligned with two opposite corners of the wafer defining a positioning notch so that the two cameras acquire actual feature images of the two corners, and the remaining cameras are aligned with the remaining edges of the wafer to acquire actual feature images of the remaining edges; comparing with ideal feature images pre-stored in a processor and determining the actual feature images of each corner and the remaining edges that meet the matching requirements as target feature images; calculating the physical position of each target feature image; calculating the translational transfer error of the wafer based on the physical positions of at least three target feature images; calculating the rotational transfer error of the wafer based on the physical positions of the target feature images of the two corners; and adjusting the position of the wafer based on the translational transfer error and the rotational transfer error.

[0005] During production, this epitaxial wafer edge-finding positive film machine is used in conjunction with a conventional robotic arm. The robotic arm is only used for picking up and placing wafers and is not responsible for adjusting their position. The positive film of the epitaxial wafer is entirely adjusted by the edge-finding positive film machine through translation along the X and Y axes and rotation around the Z axis. This positive film machine has four degrees of freedom and at least four cameras, resulting in a complex structure. The high precision requirements of the positive film machine lead to a high cost for the entire equipment. Summary of the Invention

[0006] In order to solve the technical problems of complex structure and high cost in the prior art, this application proposes an improved epitaxial wafer positive film system and a method for positive film preparation of epitaxial wafers using the system.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A positive film system includes a positive film processor, a robotic arm, and a control system. The positive film processor has a motion platform that can translate along the X-axis and rotate around the Z-axis. A suction cup is fixedly mounted on the top of the motion platform. The positive film processor also has a film stage that is configured in a generally U-shape. The suction cup is located within the U-shaped opening of the film stage, and the film stage can move up and down relative to the suction cup between a position above and below the upper surface of the suction cup.

[0009] The robotic arm has a negative pressure suction port, which can adsorb and fix the epitaxial wafer, transport the epitaxial wafer from its initial position to the wafer stage on the motion platform, and remove the epitaxial wafer after the positive wafer is finished.

[0010] The control system has sensors that can sense the position of the epitaxial wafer placed on the chuck; and a controller that can control the translational movement of the motion platform along the X-axis and the rotational movement around the Z-axis based on the information fed back by the sensors. It can also control the up-and-down movement of the wafer stage and the movement of the robot arm to achieve positive wafers.

[0011] Furthermore, the sensor in this invention is a linear array camera.

[0012] Furthermore, the motion platform includes an X-axis device and a U-axis device, the U-axis device being mounted on the X-axis device and being driven by the X-axis device to move along the X-axis direction.

[0013] Furthermore, the U-axis device includes a U-axis, and the suction cup is fixedly mounted on the top of the U-axis. The U-axis device can drive the U-axis to rotate the suction cup around the Z-axis.

[0014] Furthermore, the U-axis is a hollow structure with a rotatable quick-connect fitting at its bottom for connecting to a negative pressure device; its top is connected to an air hole on the suction cup.

[0015] Furthermore, plastic nuts are evenly distributed on the upper surfaces of both sides of the slide stage, and the height of the plastic nuts is adjustable so that their tops are located on the same horizontal plane.

[0016] Furthermore, it also includes a Z-axis device for driving the slide stage to move up and down.

[0017] Furthermore, each of the X-axis device, Z-axis device, and U-axis device has a motor-driven belt transmission mechanism and a guide mechanism consisting of a guide rail slider.

[0018] This invention also discloses a method for performing positive film using the above-mentioned positive film system. The controller pre-stores the position information of the stage, X, Y, H1, H2, ΔX, ΔH, ΔY; where X is the abscissa of the stage reference point, Y is the ordinate of the stage reference point, H1 is the Z-axis coordinate of the reference point when the stage is at its highest position, and H2 is the Z-axis coordinate of the reference point when the stage is at its lowest position; ΔX, ΔH, and ΔY are pre-set values; when the epitaxial wafer is directly below the sensor, the standard position coordinates of its center are (X... 标 Y 标 Before starting the main film, first position both the stage and the suction cup in their initial positions. The initial position of the stage is with the reference point at height H1, and the initial position of the suction cup is inside the U-shaped opening of the stage.

[0019] The main feature film process includes the following steps:

[0020] Step 1: Control the robotic arm to move to the epitaxial wafer storage location, pick up an epitaxial wafer, and transport it to the position above the wafer stage at coordinates (X, Y, H1+ΔH);

[0021] Step 2: Disconnect the negative pressure of the robot arm and move the robot arm down to (X, Y, H1-ΔH). During this process, the epitaxial wafer contacts the top of the stage and then disengages from the robot arm. After moving into position, the robot arm moves out of the stage position (X, Y-ΔY, H1-ΔH) along the Y-axis.

[0022] Step 3: The stage moves the epitaxial wafer downwards to the reference point at height H2. During this process, the epitaxial wafer contacts the chuck and detaches from the stage. The negative pressure of the chuck is turned on to adsorb and fix the epitaxial wafer on the chuck.

[0023] Step 4: The motion platform moves a distance ΔX along the X-axis with the suction cup, so that the epitaxial wafer is directly below the sensor;

[0024] Step 5: The motion platform drives the suction cup to rotate one revolution around the Z-axis. Simultaneously, the sensor collects the contour information of the epitaxial wafer at a certain frequency and sends the collected contour information to the controller. The controller processes this information to obtain the center coordinates (X1, Y1) of the epitaxial wafer and the included angle α of the flat side. Using the obtained center coordinates, the included angle of the flat side, and the pre-stored standard position (X1, Y1), the system... 标 Y 标 The correction distance X of the epitaxial wafer along the X and Y axes is calculated using plane geometry. 矫 Y 矫 ;

[0025] Step 6: The motion platform drives the suction cup to rotate around the Z-axis by an angle α, thereby correcting the flat edge;

[0026] Step 7: The motion platform moves the suction cup along the X-axis, and the distance moved is: -ΔX + X 矫 This achieves the correction of the epitaxial wafer along the X-axis direction;

[0027] Step 8: Turn off the negative pressure of the chuck, move the stage upwards until the reference point is at height H1, and at the same time move the epitaxial wafer upwards, away from the chuck by a certain distance;

[0028] Step 9: The robotic arm moves along the Y-axis by a distance of ΔY+Y. 矫 ;

[0029] Step 10: Activate the negative pressure of the robotic arm, and the robotic arm moves upward by a distance of 2ΔH, causing the epitaxial wafer to detach from the stage, thereby achieving the correction of the epitaxial wafer along the Y-axis.

[0030] Step 11: The robotic arm removes the epitaxial wafer and delivers it to the target position, marking the end of the main film process.

[0031] Furthermore, the reference point can be selected as the horizontal center of the stage or a point at the same height as the top of the stage.

[0032] The positive film device mentioned in this invention has only three degrees of freedom: movement along the X-axis, movement along the Z-axis, and rotation around the Z-axis. Compared with the prior art, it reduces movement along the Y-axis, thus omitting the drive and transmission mechanism for movement along the Y-axis. This invention only requires a linear array probe to simultaneously acquire image information multiple times by rotating the epitaxial wafer one revolution. Based on the acquired image information, the position and orientation information of the epitaxial wafer are calculated. Then, the positive film is realized by controlling the positive film machine to translate along the X-axis, rotate around the Y-axis, and the robot arm to translate along the Y-axis through a controller.

[0033] Compared with the prior art, this invention patent, while realizing the positive image of the epitaxial wafer, omits the driving and transmission mechanisms that move along the Y-axis, reduces the number of cameras, thereby reducing costs and improving work efficiency. Attached Figure Description

[0034] Figure 1 It is a schematic diagram of existing technology.

[0035] Figure 2 This is the overall three-dimensional view of the device.

[0036] Figure 3 yes Figure 2 Exploded view of the X-axis device in the middle

[0037] Figure 4 yes Figure 2 Exploded view of the Z-axis device in the middle

[0038] Figure 5 yes Figure 2 Exploded view of the U-axis device in the middle

[0039] Figure 6 This is a schematic diagram of the device of the present invention.

[0040] Figure 7 This is a diagram showing the positions of the robotic arm when picking up and placing films.

[0041] Figure 8 This is a diagram showing the position of the suction cup contacting the epitaxial wafer.

[0042] Figure 9 This is a position diagram of the epitaxial wafer edge finding positive wafer.

[0043] 1. Base plate 2. X-axis assembly 3. Sensor mounting base 4. Sensor receiver 5. Sensor transmitter 6. Epitaxial wafer 7. Robotic arm 8. Z-axis assembly 9. U-axis assembly 10. Slider I 11. Guide rail I 201. Motor I 202. Synchronous pulley I 203. X-axis motor plate 204. Positive film mount 205. Synchronous belt I 206. X-axis tension plate 207. X-axis driven shaft mount 208. Rotating shaft I 209. Bearing housing assembly I 210. Buckle I 211. Synchronous pulley II 801. Motor II 802. Synchronous pulley III 803. Belt tensioning block 804. Synchronous belt II 805. Idler pulley 806. Z-axis mounting plate 807. Buckle II 808. Guide rail II 809. Rotating shaft II 810. Slider II 811. Belt fixing block 812. Carrier stage connecting plate 813. Carrier stage 814. Plastic nut 815. Bearing housing assembly II 816. Synchronous pulley IV 901. Motor III 902. U-axis motor plate 903. Synchronous pulley V 904. Synchronous belt III 905. Suction cup 906. O-ring 907. U-axis 908. Synchronous pulley VI 909. Bearing housing assembly III 910. U-axis base 911. X-axis belt fixing block 912. U-axis spacer I 913. Bearing nut 914. Rotary quick-connect coupling 915. U-axis spacer II Specific Implementation

[0044] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0045] The positive film system of this invention includes a positive film machine, a robotic arm 7, and a control system.

[0046] The positive film processor has a base plate 1 and a motion platform. The motion platform includes an X-axis device 2 and a U-axis device 9. The U-axis device 9 is mounted on the X-axis belt fixing block 911 and slider I10 of the X-axis device 2 and can move with the synchronous belt I205. A suction cup 905 is fixedly mounted on the top of the U-axis device 9. The motion platform also includes a positive film processor mounting base 204, which is fixed to the base plate 1.

[0047] X-axis device 2 is used to drive suction cup 905 to move along the X-axis direction. Specifically, X-axis device 2 consists of: an X-axis motor plate 203 and an X-axis driven shaft mounting base 207 fixedly mounted on the film processor mounting base 204. Motor I 201 is fixedly mounted on the X-axis motor plate 203 and connected to synchronous pulley I 202. Bearing housing assembly I 209 is fixedly mounted on the X-axis driven shaft mounting base 207, rotating shaft I 208 is mounted on the bearing housing assembly I 209, synchronous pulley II 211 is fixed on rotating shaft I 208, and retaining ring I 210 is fixed to the other end of rotating shaft I 208. Synchronous belt I 205 is mounted on synchronous pulleys I 202 and II 211. Guide rail I 11 is fixed on the film processor mounting base 204, and slider I 10 is mounted on guide rail I and fixedly connected to synchronous belt I 205, allowing it to slide along guide rail I 11 with synchronous belt I 205.

[0048] The synchronous belt I205 also has a tensioning mechanism, specifically: the X-axis tensioning plate 206 is fixedly connected to the X-axis driven shaft fixing seat 207. The X-axis tensioning plate 206 is bolted to the film processor fixing seat 204. By rotating the bolts, the gap between the X-axis tensioning plate 206 and the film processor fixing seat 204 can be adjusted, thereby adjusting the position of the X-axis driven shaft fixing seat 207 in the X-axis direction. The X-axis driven shaft fixing seat 207 has a U-shaped elongated hole. After adjustment, the fixing screw is inserted through the U-shaped elongated hole and screwed into the fixing hole on the film processor fixing seat 204 to achieve tensioning of the synchronous belt I205.

[0049] The U-axis device 9 is used to drive the suction cup 905 to rotate around the Z-axis. Specifically, the U-axis device 9 consists of a U-axis base 910 fixed on a slider I 10, which is fixedly connected to a synchronous belt I 205 via an X-axis belt fixing block 911 fixedly connected to the U-axis base 910. A bearing housing assembly III 909 and a U-axis motor plate 902 are also fixedly mounted on the U-axis base 910. A motor III 901 is fixedly mounted on the U-axis motor plate 902 and connected to a synchronous pulley V 903. A U-axis 907 is located inside the bearing housing assembly III 909. U-axis spacers II 915 and I 912 are respectively fitted onto the upper and lower sides of the bearing housing assembly III 909. Above the U-shaft spacer II 915, the timing pulley VI 908 is fixed to the U-shaft 907. The timing belt III 904 is installed on the timing pulleys V 903 and VI 908, and can drive the U-shaft 907 to rotate. The suction cup 905 is fixed to the top of the U-shaft 907, and the O-ring 906 is installed between the U-shaft 907 and the suction cup 905.

[0050] Below the U-shaft spacer Ⅰ912, the U-shaft 907 is threadedly connected to a bearing nut 913, and the bottom of the U-shaft 907 is rotatably connected to a rotary quick-connect fitting 914 for connecting to a negative pressure device.

[0051] Synchronous belt Ⅲ904 also has the same tensioning mechanism as synchronous belt I205.

[0052] The positive film processor also has a film stage 813, which is roughly U-shaped with plastic nuts 814 evenly distributed on both sides. A suction cup 905 is located inside the U-shaped opening of the film stage 813, and the film stage 813 can move up and down relative to the suction cup 905 between a certain distance above and a certain distance below the upper surface of the suction cup 905.

[0053] The vertical movement of the stage 813 is driven by a Z-axis device. Specifically, the Z-axis device consists of a Z-fixed plate 806 fixedly mounted on the base plate 1, on which are fixedly mounted a motor II 801, a bearing housing assembly II 815, an idler wheel 805, and a guide rail II 808. A slider II 810 is slidably mounted on the guide rail II 808. The motor II 801 is connected to a synchronous pulley III 802. A rotating shaft II 809 is mounted on the bearing housing assembly II 815, on which are fixedly mounted a retaining ring II 807 and a synchronous pulley IV 816. A synchronous belt II 804 is mounted on the synchronous pulleys III 802 and IV 816. A belt tensioning block 803 is fixedly connected to the synchronous belt II 804. A belt fixing block 811 is fixedly installed on the belt tensioning block 803. A tray stage connecting plate 812 is fixedly installed on the belt fixing block 811. The tray stage connecting plate 812 is fixedly connected to the slider II 810. A tray stage 813 is also fixedly installed on the tray stage connecting plate 812. A plastic nut 814 is installed on the tray stage 813. The plastic nut 814 can be leveled.

[0054] The robotic arm 7 has a negative pressure suction port, which can adsorb and fix the epitaxial wafer, transport the epitaxial wafer from its initial position to the wafer stage on the motion platform, and remove the epitaxial wafer after the positive wafer is finished. It is driven by the control system through a drive device.

[0055] The control system has sensors that can sense the position status information of the epitaxial wafer placed on the wafer stage. The sensor includes a sensor receiver 4 and a sensor transmitter 5, which are respectively fixed on a sensor mounting base 3, which is fixed on the X-axis motor plate 203. Preferably, the sensor is a line scan camera.

[0056] The controller (not shown in the attached figure) can control the translational movement of the motion platform along the X-axis and the rotational movement around the Z-axis based on the information fed back by the sensors. It can also control the up-and-down movement of the stage 813 and the movement of the robot arm 7 to achieve positive film.

[0057] The controller has a storage module to store pre-set data and control programs.

[0058] When using the positive film system for positive film processing, the controller pre-stores the position information X, Y, H1, H2, ΔX, ΔH, and ΔY of the stage 813; where X is the abscissa of the stage reference point, Y is the ordinate of the stage reference point, H1 is the Z-axis coordinate of the reference point when the stage is at its highest position, and H2 is the Z-axis coordinate of the reference point when the stage is at its lowest position. The reference point can be selected as the center of the stage 813, at the same height as the top of the plastic nut 814; ΔX, ΔH, and ΔY are preset values; when the epitaxial wafer is directly below the sensor, the standard position coordinates of its center are (X... 标 Y 标 Before starting the main film, ensure that the stage and suction cup are in their initial positions. The initial state of the stage is that the reference point is at height H1.

[0059] The main feature film process includes the following steps:

[0060] Step 1: Control the robot arm 7 to move to the epitaxial wafer storage position, pick up an epitaxial wafer 6, and transport it to the position above the stage 813 at coordinates (X, Y, H1+ΔH);

[0061] Step 2: Disconnect the negative pressure of the robot arm 7 and move the robot arm 7 down to (X, Y, H1-ΔH). During this process, the epitaxial wafer 6 contacts the plastic nut 814 on the wafer stage 813 and then disengages from the robot arm 7. After moving into position, the robot arm 7 moves out of the wafer stage 813 along the Y-axis to the position (X, Y-ΔY, H1-ΔH).

[0062] Step 3: The stage 813 moves the epitaxial wafer 6 downwards to the reference point at height H2. During this process, the epitaxial wafer 6 contacts the chuck 905 and detaches from the stage 813. The negative pressure of the chuck is turned on to adsorb and fix the epitaxial wafer 6 on the chuck 905.

[0063] Step 4: The motion platform moves a distance ΔX along the X-axis with the suction cup 905, so that the epitaxial wafer 6 is located directly below the sensor;

[0064] Step 5: The motion platform drives the suction cup 905 to rotate one revolution around the Z-axis. At the same time, the sensor collects the contour information of the epitaxial wafer 6 at a certain frequency and sends the collected contour information to the controller. The controller processes the information to obtain the actual center coordinates (X1, Y1) of the epitaxial wafer 6, and also obtains the included angle α of the flat edge (also called the intercepted edge). Using the obtained center coordinates, the included angle α of the flat edge, and the pre-stored standard position (X1, Y1), the system is then used to determine the final position. 标 Y 标 Based on plane geometry, the correction distance X of epitaxial wafer 6 along the X and Y axes is calculated. 矫 Y 矫 ;

[0065] Step 6: The motion platform drives the suction cup 905 to rotate around the Z-axis by an angle α, thereby correcting the flat edge;

[0066] Step 7: The motion platform moves the suction cup 905 along the X-axis, and the distance it moves is: -ΔX + X 矫 This achieves the correction of epitaxial wafer 6 along the X-axis direction;

[0067] Step 8: Turn off the negative pressure of the chuck 905, move the stage 813 upward until the reference point is at height H1, and at the same time move the epitaxial wafer 6 upward, away from the chuck 905 by a certain distance;

[0068] Step 9: Robotic arm 7 moves along the Y-axis by a distance of ΔY+Y. 矫 ;

[0069] Step 10: Activate the negative pressure of the robotic arm, and the robotic arm 7 moves upward by a distance of 2ΔH. The epitaxial wafer 6 is removed from the stage 813, thereby realizing the correction of the epitaxial wafer 6 along the Y-axis.

[0070] Step 11: Robotic arm 7 removes epitaxial wafer 6 and delivers it to the target position, ending the main film process.

Claims

1. A method for performing positive film projection using a positive film system, wherein the controller pre-stores the position information of the film stage X, Y, H1, H2, ΔX, ΔH, ΔY; wherein, X is the x-coordinate of the stage reference point, Y is the y-coordinate of the stage reference point, H1 is the Z-axis coordinate of the reference point when the stage is at its highest position, and H2 is the Z-axis coordinate of the reference point when the stage is at its lowest position; ΔX, ΔH, and ΔY are preset values; when the epitaxial wafer is directly below the sensor, the standard position coordinates of its center are (X... 标 Y 标 Before starting the main film, first position both the stage and the suction cup in their initial positions. The initial position of the stage is with the reference point at height H1, and the initial position of the suction cup is inside the U-shaped opening of the stage. The main feature film process includes the following steps: Step 1: Control the robotic arm to move to the epitaxial wafer storage location, pick up an epitaxial wafer, and transport it to the position above the wafer stage, at coordinates (X, Y, H1+ΔH); Step 2: Disconnect the negative pressure of the robot arm and move the robot arm down to (X, Y, H1-ΔH). During this process, the epitaxial wafer contacts the top of the stage and then disengages from the robot arm. After moving into position, the robot arm moves out of the stage position (X, Y-ΔY, H1-ΔH) along the Y-axis. Step 3: The stage moves the epitaxial wafer downwards to the reference point at height H2. During this process, the epitaxial wafer contacts the chuck and detaches from the stage. The negative pressure of the chuck is turned on to adsorb and fix the epitaxial wafer on the chuck. Step 4: The motion platform moves a distance ΔX along the X-axis with the suction cup, so that the epitaxial wafer is directly below the sensor; Step 5: The motion platform drives the suction cup to rotate one revolution around the Z-axis. Simultaneously, the sensor collects the contour information of the epitaxial wafer at a certain frequency and sends the collected contour information to the controller. The controller processes this information to obtain the center coordinates (X1, Y1) of the epitaxial wafer and the included angle α of the flat side. Using the obtained center coordinates, the included angle of the flat side, and the pre-stored standard position (X1, Y1), the system... 标 Y 标 Based on plane geometry, the correction distance X of the epitaxial wafer along the X and Y axes is calculated. 矫 Y 矫 ; Step 6: The motion platform drives the suction cup to rotate around the Z-axis by an angle α, thereby correcting the flat edge; Step 7: The motion platform moves the suction cup along the X-axis, and the distance moved is: -ΔX + X 矫 This achieves the correction of the epitaxial wafer along the X-axis direction; Step 8: Turn off the negative pressure of the chuck, move the stage upwards until the reference point is at height H1, and at the same time move the epitaxial wafer upwards, away from the chuck by a certain distance; Step 9: The robotic arm moves along the Y-axis by a distance of ΔY+Y. 矫 ; Step 10: Activate the negative pressure of the robotic arm, and the robotic arm moves upward by a distance of 2ΔH, causing the epitaxial wafer to detach from the stage, thereby achieving the correction of the epitaxial wafer along the Y-axis. Step 11: The robotic arm removes the epitaxial wafer and delivers it to the target position, marking the end of the main film process.

2. A method for producing a positive film according to claim 1, wherein, The reference point is selected as the horizontal center of the slide stage (813) and the point at the same height as the top of the slide stage (813).

3. A positive film system for performing positive film using the positive film method of claim 1 or 2, comprising a positive film machine, a robotic arm (7), and a control system, characterized in that: The positive film processor has a motion platform that can translate along the X-axis and rotate around the Z-axis. A suction cup (905) is fixedly mounted on the top of the motion platform. The motion platform includes an X-axis device (2) and a U-axis device (9). The U-axis device (9) is mounted on the X-axis device (2) and can be driven by the X-axis device (2) to move along the X-axis direction. The U-axis device (9) includes a U-axis (907). The suction cup (905) is fixedly mounted on the top of the U-axis (907). The U-axis device (9) can drive the U-axis (907) to move. The shaft (907) drives the chuck (905) to rotate around the Z-axis; the positive film machine also has a film stage (813), which is set in a general U-shape; the chuck (905) is located in the U-shaped opening of the film stage (813), and the film stage (813) can move up and down relative to the chuck (905) between a certain distance above the upper surface of the chuck and a certain distance below the upper surface of the chuck; the positive film machine also has a Z-axis device (8) for driving the up and down movement of the film stage (813); The robotic arm (7) has a negative pressure suction port, which can adsorb and fix the epitaxial wafer (6), transport the epitaxial wafer (6) from the initial position to the wafer stage (813) on the motion platform, and remove the epitaxial wafer (6) after the positive wafer is finished; The control system has a sensor that can sense the position of the epitaxial wafer (6) placed on the suction cup (905); and a controller that can control the translational movement of the motion platform along the X-axis and the rotational movement around the Z-axis based on the information fed back by the sensor. It can also control the up-and-down movement of the wafer stage and the movement of the robot arm to achieve positive wafers.

4. The positive film system according to claim 3, wherein, The sensor is a linear scan camera.

5. The positive film system according to claim 3, wherein, The U-axis (907) is a hollow structure with a rotatable quick-connect connector (914) at its bottom for connecting to a negative pressure device; its top is connected to the air hole on the suction cup (905).

6. The positive film system according to claim 3, wherein, Plastic nuts (814) are evenly provided on both sides of the upper surface of the slide stage (813). The height of the plastic nuts (814) is adjustable so that their tops are on the same horizontal plane.

7. The positive film system according to claim 3, wherein, The X-axis device (2), Z-axis device (8) and U-axis device (9) each have a motor-driven belt drive mechanism and a guide mechanism consisting of a guide rail slider.

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