Method and apparatus for placing identifying mark on semiconductor wafer

摘要

A tool for placing an identifying mark on a semiconductor wafer has a bundle of optical fibers that can be illuminated in a pattern representing an identifying character. Light from the fibers is focused on a photoresist layer during wafer manufacture and a pattern of dots is etched into the wafer to represent the character. The dots are too small to be seen with the human eye but the character can be read by a human or by a machine. The character is etched as part of a conventional etch step in manufacturing the wafer and it is easily repeated as a series of manufacturing steps obscure the original mark.