High-Precision Robotic Arm for Silicon Wafer Handling and Alignment in Small-Scale Semiconductor Fabrication

Semiconductors play a critical role in almost every sector of electronics. In the United States, semiconductor manufacturing is limited, having very few large-scale automation tools compared to those in Taiwan. Instead, these smaller fabs rely heavily on human interaction with wafer handling. This can add significant points of failure such as scratching, particle defects, and stress on the wafer. The goal of this project is to develop a low-cost, automated wafer handling robotic arm with the ability to automatically align the notch of a wafer, effectively removing an entire movement step in the fabrication process. The robotic arm is able to lift a wafer from a wafer cassette and move it freely in the x-y plane while simultaneously rotating the notch to the correct alignment. The robot design is based on a dual-arm SCARA robot and is fully custom designed and manufactured. The main components of the robot include parallel dual-joint arms, a base mount for the arm motors, an end effector with a pulley belt system for wafer rotation, and a wafer notch detection and alignment system using a computer vision algorithm. Future directions for the project include manufacturing the z-axis base for vertical movement and the rotation base for rotational motion, whose preliminary designs have been already completed.