Wafer eccentricity correction device with integrated horizontal moving rotating shaft and method

Abstract

The invention discloses a wafer eccentricity correction device and method with an integrated horizontal moving rotating shaft, and belongs to the technical field of semiconductor manufacturing, and the wafer eccentricity correction device comprises a rotating shaft for bearing and rotating a wafer, a servo motor for driving the rotating shaft to rotate, a horizontal moving mechanism for driving the rotating shaft to move along the horizontal direction, and a lifting mechanism for driving the rotating shaft to move along the axial direction. According to the wafer eccentricity correction device with the integrated horizontal moving rotating shaft and the method, the distance change of the edge of the wafer before and after the rotating shaft rotates is detected through the light curtain sensor, the current eccentric angle and the eccentric distance of the wafer are calculated in cooperation with the control unit, and after the servo motor drives the rotating shaft to rotate by the current eccentric angle, the rotating shaft is driven to descend through the lifting mechanism; the horizontal moving mechanism drives the rotating shaft to move by the distance of the eccentric distance, then the lifting mechanism drives the rotating shaft to move upwards, wafer eccentricity correction is achieved through a simple structure, compared with an existing device, the problems that a three-degree-of-freedom platform is high in manufacturing cost and complex in structure are solved, and practicability is improved.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor manufacturing technology, and particularly relates to a wafer eccentricity correction device and method with an integrated horizontal moving axis. Background Technology

[0002] In semiconductor manufacturing, the accuracy of wafer transfer and positioning between process equipment is crucial. Wafer misalignment (i.e., the wafer's geometric center does not coincide with the rotation center of the equipment stage) can lead to serious problems such as out-of-tolerance photolithography overlay and deterioration of uniformity in the wafer edge areas during processes such as etching and thin film deposition, directly affecting product yield.

[0003] Most existing wafer eccentricity correction devices achieve eccentricity correction through a three-degree-of-freedom (X−Y−θ) platform. However, due to the high cost, complex structure, and difficult maintenance of the three-degree-of-freedom platform, its practicality is not ideal. Furthermore, some simplified solutions encounter interference when the wafer-carrying axis moves freely in actual use, making them difficult to implement. Summary of the Invention

[0004] To address the issues of high cost and complex structure of existing three-degree-of-freedom platforms, this invention proposes a wafer eccentricity correction device and method with an integrated horizontal moving axis.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A wafer eccentricity correction device with an integrated horizontal moving axis includes:

[0007] A hinge, used to support and rotate the wafer;

[0008] Servo motor, used to drive the rotation of the shaft;

[0009] A horizontal moving mechanism is used to drive a rotating shaft to move horizontally.

[0010] A lifting mechanism is used to drive the rotating shaft to move axially;

[0011] A wafer mounting device is used to temporarily support a wafer.

[0012] A light curtain sensor is used to measure the distance between the edge of the wafer and the center of the rotating shaft;

[0013] The control unit is electrically connected to the servo motor, the horizontal movement mechanism, the lifting mechanism, and the light curtain sensor.

[0014] A wafer eccentricity correction method with an integrated horizontal moving axis includes the following steps:

[0015] S1: The wafer is transported from the front-end module of the equipment to the wafer attachment unit. The wafer eccentricity angle is set to [value missing]. The eccentricity is L;

[0016] S2: The shaft moves upward along the axis, carrying the wafer and rotating it. Simultaneously, in conjunction with the light curtain sensor, the control unit calculates that the wafer still needs to be rotated. The shaft needs to be moved horizontally by L.

[0017] S3: The shaft drives the wafer to rotate. At this point, the eccentricity moves to the horizontal direction;

[0018] S4: The rotating shaft moves downward along the axis, and the wafer is placed on the wafer mounting device;

[0019] S5: The shaft moves horizontally by L to compensate for the eccentricity;

[0020] S6: The axis moves upward along the axis to retrieve the wafer and complete the eccentricity correction.

[0021] Preferably, step S2 includes the following steps:

[0022] S21: The rotating shaft moves upward along the axis, and the wafer is transferred from the bonding device to the rotating shaft;

[0023] S22: The distance L1 from the edge of the wafer to the center of the rotating shaft is measured by the light curtain sensor;

[0024] S23: The axis rotates by θ, and after completion, the distance L2 from the edge of the wafer to the center of the axis is measured by the light curtain sensor;

[0025] S24: Based on L1, L2, θ, wafer radius R, and the fixed angle between the light curtain of the light curtain sensor and the horizontal movement direction. And the distance L3 from the light curtain sensor measuring end to the center of the rotating shaft, the wafer eccentricity angle is calculated. And the eccentricity L.

[0026] Preferably, S24 includes:

[0027] According to L1, L2, And the wafer radius R, solve the following equations simultaneously: in, The eccentricity angle of the wafer in step S22, The rotation angle set in step S23 Given a fixed angle between the light curtain of the light curtain sensor and the horizontal movement direction, L can be calculated. The value of .

[0028] In summary, the technical effects and advantages of this invention are as follows: This wafer eccentricity correction device and method with an integrated horizontal moving shaft detects the change in distance between the wafer edge and the shaft before and after rotation using a light curtain sensor. The control unit calculates the current eccentricity angle and eccentricity distance of the wafer. After the servo motor drives the shaft to rotate to the current eccentricity angle, a lifting mechanism lowers the shaft, a horizontal moving mechanism moves the shaft by the eccentricity distance, and then the lifting mechanism raises the shaft again. This simple structure achieves wafer eccentricity correction, avoiding the high cost and complex structure of existing three-degree-of-freedom platforms and improving practicality. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the present invention;

[0030] Figure 2 This is a topological diagram of the electrical connection of the control unit in this invention;

[0031] Figure 3 This is a geometric diagram of the wafer position during step S22 of the present invention;

[0032] Figure 4 This is a geometric diagram of the wafer position during step S23 of the present invention;

[0033] Figure 5 This is a geometric diagram of the wafer position during step S3 of the present invention. Detailed Implementation

[0034] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0035] Reference Figure 1-3 A wafer eccentricity correction device with an integrated horizontal moving axis, comprising:

[0036] A hinge is used to support and rotate a wafer. It should be noted that the hinge includes a chuck for supporting the wafer, which is existing technology and will not be discussed in detail.

[0037] Servo motors are used to drive the rotation of shafts.

[0038] A horizontal moving mechanism is used to drive a rotating shaft to move horizontally.

[0039] The lifting mechanism is used to drive the rotating shaft to move axially. The lifting mechanism, horizontal moving mechanism and servo motor are all common technologies in the semiconductor manufacturing field, and their internal structures will not be described in detail here.

[0040] A wafer mounting device is used to temporarily support a wafer.

[0041] The light curtain sensor has one end facing the center of the rotating shaft. The distance from the measuring end of the light curtain sensor to the edge of the wafer is measured by the light curtain sensor. Combined with the fixed known distance from the measuring end of the light curtain sensor to the center of the rotating shaft, the distance between the edge of the wafer and the center of the rotating shaft can be obtained at this time.

[0042] The control unit is electrically connected to the servo motor, the horizontal moving mechanism, the lifting mechanism, and the light curtain sensor. The control unit processes the data from the light curtain sensor and controls the servo motor to drive the rotating shaft to rotate, controls the horizontal moving mechanism to drive the rotating shaft to move, and controls the lifting mechanism to drive the rotating shaft to move.

[0043] Reference Figure 1-3 This wafer eccentricity correction device, equipped with an integrated horizontal moving shaft, uses a light curtain sensor to detect the change in distance between the wafer edge and the shaft before and after rotation. The control unit calculates the current eccentricity angle and eccentricity distance of the wafer. After the servo motor drives the shaft to rotate to the current eccentricity angle, the horizontal line connecting the center of the shaft and the center of the wafer is parallel to the horizontal movement direction of the horizontal moving mechanism. At this time, the lifting mechanism drives the shaft to descend, and the wafer stops on the wafer mounting device. The horizontal moving mechanism drives the shaft to move the eccentricity distance, and then the lifting mechanism drives the shaft to move upward, thus realizing wafer eccentricity correction.

[0044] In addition, the rotating shaft, servo motor, and lifting mechanism are all integrated on the horizontal moving mechanism, providing ample space for the movement of the rotating shaft and wafer. The small and integrated design can avoid interference with possible external fixed bases and sensor brackets, improving practicality.

[0045] Reference Figure 1-3 A wafer eccentricity correction method with an integrated horizontal moving axis, comprising:

[0046] 1. Wafer transport and placement on the wafer mounting device

[0047] S1: The wafer is transported by the equipment front-end module and placed on the wafer mounting device. The equipment front-end module is existing technology in the wafer transfer field, so it will not be described in detail. Let's set the wafer eccentricity angle at this point as... The eccentricity is L.

[0048] II. Calculation of wafer correction rotation angle and horizontal correction movement distance

[0049] S21: The rotating shaft is driven to move upward along the axis by the lifting mechanism, and the wafer is transferred from the bonding device to the rotating shaft.

[0050] S22: Measure the distance L1 from the light curtain sensor's measuring end to the wafer edge using the light curtain sensor. Figure 3 Where O is the center of the rotation axis, O' is the current wafer center, and S is the measurement end of the light curtain sensor.

[0051] S23: The shaft rotates by θ. After completion, the distance L2 from the measuring end of the light curtain sensor to the edge of the wafer is measured by the light curtain sensor. Figure 4 .

[0052] S24: The control unit uses L1, L2, θ, wafer radius R, and the fixed angle between the light curtain sensor's light curtain and the horizontal movement direction. And the distance L3 from the measuring end of the light curtain sensor to the center of the rotating shaft, solve the following equations simultaneously: in, The initial eccentricity angle of the wafer in step S22, The rotation angle set in step S23 Given a fixed angle between the light curtain of the light curtain sensor and the horizontal movement direction, L can be calculated. The value of .

[0053] III. Compensation for Eccentricity

[0054] S3: The shaft drives the wafer to rotate. At this point, the eccentric movement is adjusted to the horizontal direction, meaning the horizontal line connecting the center of the rotating shaft and the center of the wafer is parallel to the horizontal movement direction of the horizontal moving mechanism. Figure 5 Where O is the center of the rotation axis and O' is the current wafer center.

[0055] IV. Separation of the spindle from the wafer

[0056] S4: The lifting mechanism drives the rotating shaft to move downward along the axis, and the wafer is placed on the bonding device.

[0057] V. Compensation for Eccentricity

[0058] S5: The axis moves horizontally by L to compensate for the eccentricity. At this time, the wafer center is located directly above the axis center.

[0059] VI. Retrieve the wafer

[0060] S6: The rotating shaft moves upward along the axis to retrieve the wafer. At this time, the center of the wafer coincides with the center of the rotating shaft, completing the eccentricity correction.

[0061] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A wafer eccentricity correction device with an integrated horizontal moving shaft, characterized in that, include: A hinge, used to support and rotate the wafer; Servo motor, used to drive the rotation of the shaft; A horizontal moving mechanism is used to drive a rotating shaft to move horizontally. A lifting mechanism is used to drive the rotating shaft to move axially; A wafer mounting device is used to temporarily support a wafer. A light curtain sensor is used to measure the distance between the edge of the wafer and the center of the rotating shaft; The control unit is electrically connected to the servo motor, the horizontal movement mechanism, the lifting mechanism, and the light curtain sensor.

2. The wafer eccentricity correction method with an integrated horizontal moving axis according to claim 1, characterized in that, Including the following steps: S1: The wafer is transported from the equipment front-end module to the wafer attachment unit. The wafer eccentricity angle is set to [value missing]. The eccentricity is L; S2: The shaft moves upward along the axis, carrying the wafer and rotating it. Simultaneously, in conjunction with the light curtain sensor, the control unit calculates that the wafer still needs to be rotated. The shaft needs to be moved horizontally by L; S3: The shaft drives the wafer to rotate. At this point, the eccentricity moves to the horizontal direction; S4: The rotating shaft moves downward along the axis, and the wafer is placed on the wafer mounting device; S5: The shaft moves horizontally by L to compensate for the eccentricity; S6: The axis moves upward along the axis to retrieve the wafer and complete the eccentricity correction.

3. The wafer eccentricity correction method with an integrated horizontal moving axis according to claim 2, characterized in that, S2 includes the following steps: S21: The rotating shaft moves upward along the axis, and the wafer is transferred from the bonding device to the rotating shaft; S22: Measure the distance L1 from the measuring end of the light curtain sensor to the edge of the wafer at this time using the light curtain sensor; S23: Rotate the shaft by θ, and after completion, measure the distance L2 from the measuring end of the light curtain sensor to the edge of the wafer using the light curtain sensor. S24: Based on L1, L2, θ, wafer radius R, and the fixed angle between the light curtain of the light curtain sensor and the horizontal movement direction. And the distance L3 from the light curtain sensor measuring end to the center of the rotating shaft, the wafer eccentricity angle is calculated. And the eccentricity L.

4. The wafer eccentricity correction method with an integrated horizontal moving axis according to claim 3, characterized in that, S24 includes: According to L1, L2, Given the wafer radius R, we can solve the following equations simultaneously: in, The eccentricity angle of the wafer in step S22, The rotation angle set in step S23 Given a fixed angle between the light curtain of the light curtain sensor and the horizontal movement direction, L can be calculated. The value of .

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