Wafer wobbling detection method and wafer wobbling detection system

Abstract

To provide a method and its system capable of detecting wobbling of a wafer while an operation is performed in a semiconductor processing device.SOLUTION: A wafer wobbling detection method is applied to a semiconductor processing device that performs a process while an internally mounted wafer is rotated. The method includes: a step of securing a wafer surface image such that a reflection image which is reflecting, on a surface of a wafer, a fixture mounted inside the processing device and having a fixed position is included in the wafer surface image; and a step of detecting wobbling of the wafer by analyzing the reflection image in the secured image, the reflection image being moved due to wobbling.SELECTED DRAWING: Figure 1

Claims

1. A wafer wobbling detection method applied to semiconductor equipment that performs a process while rotating a wafer installed inside, A step of acquiring a wafer surface image such that it includes a reflected image of a fixed object installed inside the equipment and fixed in position reflected on the wafer surface, A wafer wobbling detection method characterized by comprising the step of detecting wafer wobbling by analyzing the position of the reflected image moving due to wobbling in the acquired image.

2. The process of analyzing the position of the reflected image is, A predetermined position in the image is set as the normal region, and a first abnormal region is set so as to surround the normal region. The wafer wobbling detection method according to claim 1, characterized in that it is performed by calculating the proportion of each region to which the reflected image in the image belongs.

3. The wafer wobbling detection method according to claim 2, characterized in that an offset region having a predetermined width is further set between the normal region and the first abnormal region.

4. The wafer wobbling detection method according to claim 2, characterized in that a second abnormal region is further set, which is arranged to surround the first abnormal region.

5. The wafer wobbling detection method according to claim 4, characterized in that an upper limit is set for the proportion in which a reflected image may be included in the first abnormal region and the second abnormal region, and if the proportion of reflected images calculated from the image is higher than each of these upper limits, it is determined to be abnormal wobbling.

6. The process of analyzing the position of the reflected image is, A closed curve is set where pixels are connected at predetermined positions in the image. The wafer wobbling detection method according to claim 1, characterized in that, after assigning a number to each pixel included in the closed curve, the direction of wobbling can be detected from the number of the pixel where the reflected image is mainly located.

7. A wafer wobbling sensing system applied to semiconductor equipment that performs a process while rotating a wafer installed inside, Fixed objects installed inside the equipment and whose position is fixed, A camera that acquires a surface image of a wafer such that the fixed object is reflected onto the wafer surface, It includes a machine vision analysis unit that analyzes acquired images to detect wafer wobbling, The aforementioned machine vision analysis unit is A wafer wobbling detection system characterized by detecting wafer wobbling by analyzing the position of the reflected image moving due to wobbling in the acquired image.

8. The aforementioned machine vision analysis unit is The wafer wobbling detection system according to claim 7, characterized in that a predetermined position in the image is set as a normal region, a first abnormal region is set so as to surround the normal region, and the proportion of each region to which the reflected image in the image belongs is calculated.

9. The aforementioned machine vision analysis unit is The wafer wobbling detection system according to claim 8, further characterized in that an offset region having a predetermined width is set between the normal region and the first abnormal region.

10. The wafer wobbling detection system according to claim 8, characterized in that the machine vision analysis unit further sets a second abnormal region arranged to surround the first abnormal region.

11. The aforementioned machine vision analysis unit is The wafer wobbling detection system according to claim 10, characterized in that an upper limit is set for the proportion in which a reflected image may be included in the first abnormal region and the second abnormal region, and abnormal wobbling is determined when the proportion of reflected images calculated from the image is higher than each of the upper limits.

12. The aforementioned machine vision analysis unit is A closed curve is set where pixels are connected at predetermined positions in the image. The wafer wobbling detection system according to claim 7, characterized in that, after assigning a number to each pixel included in the closed curve, the direction of wobbling can be detected from the number of the pixel where the reflected image is mainly located.

Images