WAFER HOLDER WITH VACUUM SENSOR AND METHOD OF SENSING AND ADJUSTING WAFER POSITION THEREOF

摘要

A wafer holder having a vacuum sensor and a method for sensing and adjusting a wafer position thereof are provided to sense a loading error of a wafer and to reduce an error rate by using a vacuum sensing method. A wafer holder of a stepper includes vacuum holes formed thereon. The vacuum hole is used for checking vacuum pressure. Three vacuum holes are installed at an interval of 120 degrees on an edge of a circumference of the wafer holder. One of the vacuum holes is installed at a notch part of the wafer holder. A method for sensing a wafer position on the wafer holder includes a process for sensing the wafer position on the wafer holder by sensing the vacuum pressure of the vacuum holes.