Position Error Inspection for Mounting Wafer in Cleaning Device

Recently, many inspection systems are using computer vision technology. We also use computer vision to recognize the position error for mounting a wafer in a cleaning process of the semiconductor production processes. The robot moves wafer to the cleaning chamber. But sometime, the robot puts the wafer into an incorrect location. In this case, incorrect position becomes cause of the cleaning system trouble or the wafer´s broken. In this paper, we propose a position error recognition system using multiple cameras based on Giga Ethernet in multi-cleaning system. This is carried out by capturing image by high frame rate, followed by doing calibration and image processing to check the wafer´s position before the cleaning process starts. If the robot puts the wafer in the incorrect location, the machine stops the cleaning process. So, we can prevent the wafer from being broken or the machine from being disturbing the cleaning process.