Systems and methods of controlling semiconductor wafer fabrication processes

摘要

A system and method of controlling a semiconductor wafer fabrication process. The method includes positioning a semiconductor wafer on a wafer support assembly in a wafer processing module. A signal is transmitted from a signal emitter positioned at a predetermined transmission angle relative to an axis normal to the wafer support assembly to check leveling of the wafer in the module, so that the signal is reflected from the wafer. The embodiment includes monitoring for the reflected signal at a predetermined reflectance angle relative to the axis normal to the wafer support assembly at a signal receiver. A warning indication is generated if the reflected signal is not received at the signal receiver.

主权项

1. A method of controlling a semiconductor wafer fabrication process, comprising:
positioning a semiconductor wafer on a planar surface of a wafer support assembly in a wafer processing module; determining an estimated reflectance angle measured relative to an axis normal to the planar surface of the wafer support assembly when the wafer is supported by the wafer support assembly and relative to a selected reflectance point offset from a center of the wafer by a selected distance measured parallel to an axis of the planar surface of the wafer support assembly; positioning a signal emitter along a first sidewall of the wafer processing module at a first distance from the planar surface of the wafer support assembly measured parallel to the axis normal to the planar surface of the wafer support assembly and at a determined transmission angle to the selected reflectance point, wherein the determined transmission angle is measured relative to the axis normal to the planar surface of the wafer support assembly when the wafer is supported by the wafer support assembly; positioning a signal receiver along a second sidewall of the wafer processing module opposite the first sidewall and at a second distance from the planar surface of the wafer support assembly measured parallel to the axis normal to the planar surface of the wafer support assembly, wherein the first distance is different than the second distance and wherein the respective first and second distances are determined based on the estimated reflectance angle, the determined transmission angle, and the selected reflectance point; transmitting a signal from the signal emitter to the selected reflectance point to check leveling of the wafer in the module; monitoring for the reflected signal at the signal receiver at the estimated reflectance angle; and generating a warning indication if the reflected signal is not received at the signal receiver.