Wafer pre-alignment method and device

Abstract

The invention is suitable for the technical field of wafer processing, and provides a wafer pre-alignment method and device. According to the invention, after the wafer is placed, illumination supplementation is carried out, and the wafer is shot to obtain shot image data; the shot image data is analyzed and calculated, the position deviation of the wafer corner cut is determined, and corresponding adjustment parameters are planned; and performing multi-directional alignment adjustment on the wafer according to the adjustment parameters. According to the wafer pre-alignment method and device, efficient optical detection and image processing processes can be achieved, the alignment precision can be improved, high-level operation automation can be achieved, the requirement of a large-scale production environment can be met, the application effect of wafer pre-alignment in semiconductor manufacturing can be remarkably improved, and the more efficient and more accurate alignment effect can be provided.

Description

Technical Field

[0001] The invention belongs to the technical field of wafer processing, and in particular relates to a wafer pre-alignment method and device. Background Art

[0002] During the wafer processing process, wafer pre-alignment equipment plays a key role to ensure the accurate positioning of the wafer before the processing station or inspection station.

[0003] The invention patent with authorization announcement number CN117712006A provides a wafer pre-alignment device, which belongs to the field of wafer detection technology. The wafer pre-alignment device includes a base, and a calibration component and a visual detection component are arranged above the base. The calibration component can move back and forth under the visual detection component; the calibration component includes a calibration shell, and an air pipe is arranged under the calibration shell, and the air pipe is connected to the air path of the calibration shell; an opening is provided on the top of the calibration shell; a suction cup is arranged inside the calibration shell, and the suction cup is provided with an adsorption hole body, and a calibration base block is arranged on the outer edge of the suction cup, and the calibration base block can move back and forth along the radial direction of the suction cup; a rotating part is arranged on the inner edge of the calibration base block, and the rotating part can rotate around a vertical axis.

[0004] However, existing wafer alignment devices have some shortcomings, including: (1) the existing equipment has low alignment accuracy when processing wafers of different materials; (2) in a high-speed production environment, the equipment response time is long and cannot meet the requirements of high-efficiency production; (3) the automation level of the equipment needs to be improved, and errors are easily caused by human operation. Summary of the invention

[0005] The purpose of the embodiments of the present invention is to provide a wafer pre-alignment method and device, aiming to solve the technical problems existing in the prior art mentioned in the background technology.

[0006] The embodiment of the present invention is implemented as follows:

[0007] A wafer pre-alignment method, the method specifically comprising the following steps:

[0008] After the wafer is placed, supplement the light, and photograph the wafer to obtain the photographed image data;

[0009] Analyze and calculate the captured image data, determine the position deviation of the wafer cutting angle, and plan corresponding adjustment parameters;

[0010] According to the adjustment parameters, the wafer is aligned and adjusted in all directions.

[0011] As a further limitation of the technical solution of the embodiment of the present invention, the analyzing and calculating the captured image data, determining the position deviation of the wafer cutting angle, and planning the corresponding adjustment parameters specifically include the following steps:

[0012] Set the standard position of the wafer at the processing station;

[0013] Based on the standard position, analyzing and calculating the captured image data to determine the position deviation of the wafer cutting angle;

[0014] According to the position deviation, corresponding adjustment parameters are planned.

[0015] As a further limitation of the technical solution of the embodiment of the present invention, the analyzing and calculating the captured image data based on the standard position to determine the position deviation of the wafer cutting angle specifically includes the following steps:

[0016] Based on the standard position, analyzing and calculating the captured image data to obtain current position data of the wafer;

[0017] Determining a current rotation angle of the wafer according to the captured image data;

[0018] The position deviation of the wafer cutting angle is calculated according to the current position data and the current rotation angle.

[0019] As a further limitation of the technical solution of the embodiment of the present invention, the calculation formula for analyzing and calculating the captured image data to obtain the current position data of the wafer is:

[0020] Xc=X·cos(r)-Y·sin(r)+Xt·(1-cos(r))+Yt·sin(r);

[0021] Yc=X·sin(r)+Y·cos(r)-Xt·sin(r)+Yt·(1-cos(r));

[0022] Wherein, Xc is the current X coordinate of the wafer, Yc is the current Y coordinate of the wafer, Xt is the X coordinate of the standard position, Yt is the Y coordinate of the standard position, and r is the interval image rotation angle.

[0023] As a further limitation of the technical solution of the embodiment of the present invention, the calculation formula for calculating the position deviation of the wafer cutting angle according to the current position data and the current rotation angle is:

[0024] ΔX=Xt-Xc;

[0025] ΔY=Yt-Yc;

[0026] Δθ=θt-θc;

[0027] Among them, ΔX is the deviation in the X direction, ΔY is the deviation in the Y direction, Δθ is the angle deviation, θt is the rotation angle of the standard position, and θc is the current rotation angle of the wafer.

[0028] As a further limitation of the technical solution of the embodiment of the present invention, the multi-directional alignment adjustment of the wafer according to the adjustment parameters specifically includes the following steps:

[0029] performing coordinated control of the motion according to the adjustment parameters;

[0030] The wafer is aligned in the XY plane and around the θ axis to adjust the wafer to the standard position.

[0031] A wafer pre-alignment device, comprising a light source lamp, a camera, an industrial computer, a PLC and a mechanical platform, wherein:

[0032] Light source lamp, used to supplement lighting after the wafer is placed;

[0033] A camera is used to photograph the wafer and obtain photographed image data;

[0034] An industrial computer is used to analyze and calculate the captured image data, determine the position deviation of the wafer cutting angle, and plan corresponding adjustment parameters;

[0035] The PLC and mechanical platform are used to perform multi-directional alignment adjustment on the wafer according to the adjustment parameters.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] The embodiment of the present invention supplements the illumination after the wafer is placed, and photographs the wafer to obtain the photographed image data; analyzes and calculates the photographed image data to determine the position deviation of the wafer cutting angle and plan the corresponding adjustment parameters; and performs multi-directional alignment adjustment on the wafer according to the adjustment parameters. It can have an efficient optical detection and image processing process, improve the alignment accuracy, and achieve a high level of operation automation to meet the needs of large-scale production environments, thereby significantly improving the application effect of wafer pre-alignment in semiconductor manufacturing and providing a more efficient and accurate alignment effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A flow chart of a wafer pre-alignment method provided by an embodiment of the present invention is shown;

[0039] Figure 2 A schematic diagram showing a method for determining a position deviation of a wafer cutting angle in an embodiment of the present invention is shown;

[0040] Figure 3 The overall structure diagram of the wafer pre-alignment device provided by the embodiment of the present invention is shown;

[0041] Figure 4A partial structural diagram of a wafer pre-alignment device provided in an embodiment of the present invention is shown.

[0042] In the attached figure: 1. light source; 2. camera; 3. industrial computer; 4. PLC; 5. mechanical platform. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0044] It is understandable that there are some shortcomings in the wafer alignment device in the prior art, including: (1) the existing equipment has low alignment accuracy when processing wafers of different materials; (2) in a high-speed production environment, the equipment response time is long and cannot meet the requirements of high-efficiency production; (3) the degree of automation of the equipment needs to be improved, and errors are easily caused by human operation.

[0045] To solve the above problems, the embodiment of the present invention discloses a wafer pre-alignment method and device, which supplements the light after the wafer is placed, shoots the wafer, and obtains the captured image data; analyzes and calculates the captured image data, determines the position deviation of the wafer cutting angle, and plans the corresponding adjustment parameters; and performs multi-directional alignment adjustment on the wafer according to the adjustment parameters. It can have efficient optical detection and image processing processes, improve alignment accuracy, and achieve a high level of operation automation to meet the needs of large-scale production environments, thereby significantly improving the application effect of wafer pre-alignment in semiconductor manufacturing and providing more efficient and accurate alignment effects.

[0046] Specifically, Figure 1 A flow chart of a wafer pre-alignment method provided by an embodiment of the present invention is shown.

[0047] In a preferred embodiment of the present invention, a wafer pre-alignment method is provided, the method specifically comprising the following steps:

[0048] Step S101: After the wafer is placed, supplement the lighting, and photograph the wafer to obtain photographed image data.

[0049] Step S102: Analyze and calculate the captured image data, determine the position deviation of the wafer cutting angle, and plan corresponding adjustment parameters.

[0050] In the embodiment of the present invention, Figure 2A schematic diagram of determining the position deviation of the wafer cutting angle in the method provided by an embodiment of the present invention is shown. By setting the standard position of the wafer at the processing station, the captured image data is analyzed and calculated based on the standard position to obtain the current position data of the wafer, and the current rotation angle of the wafer is determined according to the captured image data. According to the current position data and the current rotation angle, the position deviation of the wafer cutting angle is calculated, and then according to the position deviation, the corresponding adjustment parameters are planned. Specifically, the captured image data is analyzed and calculated, and the calculation formula for obtaining the current position data of the wafer is:

[0051] Xc=X·cos(r)-Y·sin(r)+Xt·(1-cos(r))+Yt·sin(r);

[0052] Yc=X·sin(r)+Y·cos(r)-Xt·sin(r)+Yt·(1-cos(r));

[0053] Wherein, Xc is the current X coordinate of the wafer, Yc is the current Y coordinate of the wafer, Xt is the X coordinate of the standard position, Yt is the Y coordinate of the standard position, and r is the interval image rotation angle;

[0054] According to the current position data and the current rotation angle, the calculation formula for the position deviation of the wafer cutting angle is:

[0055] ΔX=Xt-Xc;

[0056] ΔY=Yt-Yc;

[0057] Δθ=θt-θc;

[0058] Among them, ΔX is the deviation in the X direction, ΔY is the deviation in the Y direction, Δθ is the angle deviation, θt is the rotation angle of the standard position, and θc is the current rotation angle of the wafer.

[0059] It can be understood that the standard position is recorded as (Xt, Yt, θt); the current position data is recorded as (Xc, Yc); the current rotation angle is recorded as θc; and the position deviation is recorded as (ΔX, ΔY, Δθ).

[0060] It can be understood that the data points of each image are first obtained and converted (conversion formula: Xc=X·cos(r)-Y·sin(r)+Xt·(1-cos(r))+Yt·sin(r); Yc=X·sin(r)+Y·cos(r)-Xt·sin(r)+Yt·(1-cos(r))) to the actual position, and then a circle is fitted according to all the data (using VisionPro's CogFitCircleTool for fitting), and the current position data is obtained according to the fitted circle, recorded as (Xc, Yc), and the notch position is located according to the acquired image (using VisionPro's CogPMAlignTool for positioning) to obtain the current rotation angle θc of the wafer.

[0061] Step S103 : performing multi-directional alignment adjustment on the wafer according to the adjustment parameters.

[0062] In the embodiment of the present invention, the motion is coordinated and controlled through precise control of the servo motor according to the adjustment parameters, thereby adjusting the alignment of the wafer in the XY plane and around the θ axis, so that the wafer is adjusted to a standard position.

[0063] Furthermore, Figure 3 The overall structure diagram of the wafer pre-alignment device provided by the embodiment of the present invention is shown. Figure 4 A partial structural diagram of a wafer pre-alignment device provided in an embodiment of the present invention is shown.

[0064] Among them, in another preferred embodiment provided by the present invention, a wafer pre-alignment device is characterized by comprising:

[0065] The light source lamp 1 is used to provide supplementary lighting after the wafer is placed.

[0066] Camera 2 is used to photograph the wafer and obtain photographed image data.

[0067] The industrial computer 3 is used to analyze and calculate the captured image data, determine the position deviation of the wafer cutting angle, and plan corresponding adjustment parameters.

[0068] The PLC 4 and the mechanical platform 5 are used to perform multi-directional alignment adjustment on the wafer according to the adjustment parameters.

[0069] It can be understood that the camera 2 relies on the illumination provided by the light source lamp 1 for image acquisition, and the two work closely together to ensure that the image quality meets the standards. The image data acquired by the camera 2 is input into the industrial computer 3, which analyzes the data and provides corresponding adjustment instructions. The instructions output by the industrial computer 3 are transmitted to the mechanical platform 5 through the PLC 4 to control its movement and alignment. The PLC 4 coordinates the movement of the mechanical platform 5 to ensure that it accurately executes the instructions of the industrial computer 3.

[0070] It should be understood that, although each step in the flow chart of each embodiment of the present invention is shown in sequence according to the indication of the arrow, these steps are not necessarily performed in sequence according to the order indicated by the arrow. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be performed in other orders. Moreover, at least a portion of the steps in each embodiment may include a plurality of sub-steps or a plurality of stages, and these sub-steps or stages are not necessarily performed at the same time, but can be performed at different times, and the execution order of these sub-steps or stages is not necessarily performed in sequence, but can be performed in turn or alternately with at least a portion of other steps or sub-steps or stages of other steps.

[0071] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0072] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A wafer pre-alignment method, characterized in that: The method specifically comprises the following steps: After the wafer is placed, supplement the light, and photograph the wafer to obtain the photographed image data; Analyze and calculate the captured image data, determine the position deviation of the wafer cutting angle, and plan corresponding adjustment parameters; According to the adjustment parameters, the wafer is aligned and adjusted in all directions.

2. The wafer pre-alignment method according to claim 1, characterized in that: The analyzing and calculating the captured image data, determining the position deviation of the wafer cutting angle, and planning the corresponding adjustment parameters specifically include the following steps: Set the standard position of the wafer at the processing station; Based on the standard position, analyzing and calculating the captured image data to determine the position deviation of the wafer cutting angle; According to the position deviation, corresponding adjustment parameters are planned.

3. The wafer pre-alignment method according to claim 2, characterized in that: The analyzing and calculating the captured image data based on the standard position to determine the position deviation of the wafer cutting angle specifically comprises the following steps: Based on the standard position, analyzing and calculating the captured image data to obtain current position data of the wafer; Determining a current rotation angle of the wafer according to the captured image data; The position deviation of the wafer cutting angle is calculated according to the current position data and the current rotation angle.

4. The wafer pre-alignment method according to claim 3, characterized in that: The calculation formula for analyzing and calculating the captured image data to obtain the current position data of the wafer is: Xc=X·cos(r)-Y·sin(r)+Xt·(1-cos(r))+Yt·sin(r); Yc=X·sin(r)+Y·cos(r)-Xt·sin(r)+Yt·(1-cos(r)); Wherein, Xc is the current X coordinate of the wafer, Yc is the current Y coordinate of the wafer, Xt is the X coordinate of the standard position, Yt is the Y coordinate of the standard position, and r is the interval image rotation angle.

5. The wafer pre-alignment method according to claim 4, characterized in that: The calculation formula for calculating the position deviation of the wafer cutting angle according to the current position data and the current rotation angle is: ΔX=Xt-Xc; ΔY=Yt-Yc; Δθ=θt-θc; Among them, ΔX is the deviation in the X direction, ΔY is the deviation in the Y direction, Δθ is the angle deviation, θt is the rotation angle of the standard position, and θc is the current rotation angle of the wafer.

6. The wafer pre-alignment method according to claim 2, characterized in that: The multi-directional alignment adjustment of the wafer according to the adjustment parameters specifically includes the following steps: performing coordinated control of the motion according to the adjustment parameters; The wafer is aligned in the XY plane and around the θ axis to adjust the wafer to the standard position.

7. A wafer pre-alignment device, characterized in that: The device comprises a light source lamp (1), a camera (2), an industrial computer (3), a PLC (4) and a mechanical platform (5), wherein: A light source lamp (1) is used to provide additional lighting after the wafer is placed; A camera (2) is used to photograph the wafer and obtain photographed image data; An industrial computer (3) is used to analyze and calculate the captured image data, determine the position deviation of the wafer cutting angle, and plan corresponding adjustment parameters; The PLC (4) and the mechanical platform (5) are used to perform multi-directional alignment adjustment on the wafer according to the adjustment parameters.

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