Wafer positioning check in vertical semiconductor furnaces

摘要

A wafer positioning checking system used in a vertical furnace as found in a semiconductor manufacturing facility for manufacturing chips. The system utilizes a first sensor such as a photoelectric or laser sensor that checks the peripheral alignment of the wafers loaded in the boat. A second sensor is mounted on a robot having a wafer-handling arm for checking the position of a wafer that has just been loaded into the boat. An algorithm in a control unit responds to electrical signals generated by these two sensors to allow the loading operation to continue as long as the wafers are properly positioned and to controllable monitoring the wafers during a portion of the processing.