A method for adjusting the speed of a manipulator based on the orientation result of an orientation platform

Abstract

The present invention is generally an application scenario of adjusting the movement speed of a manipulator in a semiconductor ion implantation process. More specifically, it is a scenario of adjusting the speed of a vacuum manipulator in an ion implanter during wafer transfer. This method can improve the stability and accuracy of the wafer transfer system, thereby increasing production capacity. It belongs to the semiconductor field.

Description

Technical Field

[0001] This method is generally applied to the scenario of adjusting the movement speed of the robot in the semiconductor ion implantation process. More specifically, it is the scenario of adjusting the speed of the vacuum robot in the ion implantation machine during the wafer transfer process. Background Art

[0002] In the field of ion implantation, the implantation angle when ions are implanted into the wafer, the lattice direction of the wafer, and the transfer accuracy during wafer transfer are of great significance to the process of ion implantation. Among them, the accuracy and stability of wafer transfer have the most direct impact on the production efficiency of the equipment. Improving the accuracy and stability of wafer transfer will directly increase the output of the machine and thus improve the production efficiency of the enterprise.

[0003] In the existing ion implanter, the manipulator for transferring wafers and the orientation table for achieving wafer orientation are two indispensable parts of the machine. Improving the stability and accuracy of the wafer transmission system depends largely on improving the stability and accuracy of the manipulator transmission and wafer orientation. The most important thing in this process is to ensure that the wafer does not shift during the movement of the manipulator, otherwise the orientation table will not be able to achieve wafer orientation, and the safety during the transmission process cannot be guaranteed, resulting in the wafer slipping and damage. The traditional vacuum manipulator speed adjustment is adjusted by manual memory. It is inefficient, poor in accuracy, and requires destroying the stable state of the vacuum chamber. In most cases, it is adjusted by human eye observation, with poor accuracy, and it is impossible to accurately determine the offset of the wafer on the manipulator finger.

[0004] Therefore, an orientation table calibration method is needed to determine whether the orientation table calibration is accurate through the feedback value of the precise feedback device, and the implementation method is simple and convenient to adjust the speed of the robot. Therefore, a method for adjusting the robot hand speed based on the orientation result of the orientation table is introduced. This method is based on the feedback of the light sense value of the orientation table. According to the feedback value fluctuation of the light sense value when the wafer rotates one circle on the orientation table, it is determined whether the wafer is offset during the movement of the robot. And the deviation value of the wafer on the orientation table is deduced according to the feedback value. Through calculation, it is known that the robot should move to the position and then retrieve it at a slow speed. Reset the speed of the robot according to the size of the deviation value. Repeat the above steps and finally reach a good result through iteration. Summary of the invention

[0005] Aiming at the low efficiency and poor accuracy of the existing manual calibration of the manipulator hand speed and the influence on the stable state of the equipment, the present invention introduces a method for adjusting the manipulator hand speed based on the orientation result of the orientation platform.

[0006] The present invention is achieved through the following technical solutions:

[0007] 1. A method for adjusting the speed of a manipulator based on an orientation result of an orientation platform, comprising an orientation platform (1), a controller (2), an industrial computer (3), and a manipulator (4).

[0008] 2. A method for adjusting the speed of a manipulator based on the orientation result of an orientation platform, wherein the process is as follows: after the orientation platform and the manipulator are slowly calibrated, the manipulator places the wafer on the orientation platform (1) at an initial speed, and the orientation platform (1) completes the measurement of the silicon wafer related information. The specific operation is as follows: the orientation platform is controlled to rotate 360 ​​degrees, and during the rotation process, the information is collected at equal intervals according to the position value of the encoder. The collected results are sent to the controller (2), and the controller (2) then uploads the information to the industrial computer (3). The industrial computer (3) calculates the position offset of the silicon wafer on the orientation platform (1), and converts the offset into the position compensation of the manipulator (4) coordinates, and calculates the new position of the manipulator when taking the wafer (this position can ensure that the wafer can be placed in the center of the manipulator finger), and sends this position to the manipulator (4). The manipulator (4) completes the task of picking up and placing the silicon wafer on the orientation platform (1). Then it returns to the calibrated workstation and places it on the orientation platform at another speed. Repeat the above operation until the robot speed is increased to the maximum acceleration while the wafer does not deviate during the transmission process, thereby ensuring the accuracy and stability of wafer transmission.

[0009] 3. A method for adjusting the speed of the manipulator based on the orientation result of the orientation platform, such as Figure 2 and Figure 3 As shown in the figure: the rotation centers of the orientation stage (1) and the wafer (5) on the orientation stage are A and B respectively. When the orientation stage (1) rotates, it drives the wafer (5) to rotate. During the rotation, the wafer (5) blocks the photosensitive sensor (7), causing the feedback value of the photosensitive sensor (7) to change. There is a certain mathematical vector relationship between the center of the wafer (5) and the orientation stage (1). Through derivation, it can be known that the relationship between the orientation stage encoder position and the sensor light intensity is a sinusoidal curve. When the gap is zero, the curve of the orientation stage encoder position and the sensor light intensity is a straight line. When the deviation is not zero, it is a sinusoidal curve, such as Figure 4 The host computer PC can calculate the deviation value through the relationship between the rotation angle of the orientation platform (1) and the light sensitivity value, specifically the size of the offset and the angle θ between the offset and the reference line (6).

[0010] The present invention has the following significant advantages:

[0011] 1. The present invention has high efficiency and high precision in adjusting the speed of the manipulator, does not affect the stable state of the equipment during operation, and avoids the disadvantages of manual calibration.

[0012] 2. The offset is the offset between the center of the wafer and the center of the orientation stage. Based on this amount, the offset of the robot under the current speed and acceleration can be calculated. Based on this amount, the appropriate compensation amount is calculated so that when the robot takes the wafer, the wafer coincides with the center of the finger.

[0013] 3. The calculated quantities can be used to effectively adjust the speed and acceleration of the robot.

[0014] 4. The present invention can be iterated multiple times, and the highest movement speed and acceleration can be obtained through iteration without causing deviation during wafer transmission, thereby maximizing production capacity while ensuring accuracy and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is the architecture diagram of the automatic calibration system for silicon wafers on the orientation table.

[0016] Figure 2 This is the schematic diagram of the implementation principle of the directional function of the directional station.

[0017] Figure 3 This is the implementation diagram of the calculation of the deviation between the center of the silicon wafer and the center of the orientation stage.

[0018] Figure 4 It is the position-light intensity curve when the silicon wafer is offset on the orientation stage. DETAILED DESCRIPTION

[0019] The following is combined with Figure 1 , Attachment Figure 2 , Attachment Figure 3 and attached Figure 4 The present invention is further introduced.

[0020] On the premise that the manipulator (4) has completed calibration at the workstation of the orientation platform (1), the manipulator (4) places the wafer (5) on the orientation platform (1). The industrial computer (3) issues instructions to the control controller (2). The controller (2) controls the orientation platform (1) to rotate at a constant speed for one circle, and performs the task of periodically collecting feedback from the light sensor according to the feedback value of the encoder. After completion, the controller (2) sends the collected position-light intensity data to the industrial computer (3). The industrial computer calculates the data and determines whether an offset occurs during the wafer transfer process. If an offset occurs, the offset size and the compensation value when the manipulator (4) takes the wafer are calculated. The offset is converted into a position vector based on the coordinate system of the manipulator (4), and this position is sent to the manipulator (4). The position compensation of the manipulator (4) requires position coordinate transformation. The position calibration amount is obtained through large-scale experiments by looking up the empirical value in the table data. The angle offset is determined by the maximum and minimum values ​​in the position-light intensity curve.

Claims

1. A method for adjusting the speed of a manipulator based on the orientation result of an orientation platform, which can control the speed and precision of a wafer during the wafer transmission process with high precision, comprises an orientation platform (1), a controller (2), an industrial computer (3), and a manipulator (4). After the orientation platform and the manipulator are calibrated at a slow speed, the manipulator places the wafer on the orientation platform (1) at an initial speed, and the orientation platform (1) completes the measurement of information related to the silicon wafer. The specific operation is: controlling the rotation of the orientation platform to collect position-light intensity data at equal intervals according to the position value of the encoder during the rotation process; determining whether the wafer is offset during the movement of the manipulator (4) according to the feedback value fluctuation of the light sense value after the wafer rotates one circle on the orientation platform (1), and sending the collected results to the controller (2), and the controller (2) then uploads the information to the industrial computer (3). , the industrial computer (3) calculates the position offset of the silicon wafer on the orientation table (1), and converts this offset into the position compensation of the robot (4) coordinates, and calculates the new position of the robot when taking the wafer. This position can ensure that the wafer can be placed centered on the robot finger, and sends this position to the robot (4); the robot (4) completes the task of taking and placing the silicon wafer on the orientation table (1); then returns to the calibrated workstation and places it on the orientation table at another speed; through multiple iterations, the highest movement speed and acceleration are obtained under the premise that no offset occurs during the wafer transmission process. The orientation table encoder position-light intensity data is a sinusoidal curve relationship. When the gap is zero, the orientation table encoder position-sensor light intensity curve is a straight line. When the deviation is not zero, it is a sinusoidal curve.

2. A method for adjusting the speed of a robot based on the orientation results of an orientation table as described in claim 1, wherein the robot speed adjustment method is based on the offset between the center of the wafer and the center of the orientation table during the orientation process, and the offset of the robot under the current speed and acceleration is calculated based on this quantity, and the compensation amount is calculated based on this quantity so that when the robot takes the wafer, the wafer coincides with the center of the finger.

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