Wafer rotation in wafer handling devices

摘要

Tracking the movement of individual wafers in a semiconductor processing system is improved by using an apparatus to axially rotate a wafer and using both the rotation angle and the wafer's location in the processing system as tracking coordinates. In an example embodiment, the apparatus imparts angles of rotation on the wafers in different stages of wafer processing. The rotation angles of each wafer are collected as data along with the wafer's location in the process. The combined wafer location and angle of rotation data are used to map the path the wafer has traveled from the onset of processing. An important advantage to this apparatus is the increased control and improved yields that the apparatus brings to wafer processing.