Use of scatterometry for in-situ control of gaseous phase chemical trim process

Abstract

A system for regulating a gaseous phase chemical trim process is provided. The system includes one or more light sources, each light source directing light to one or more features and/or gratings on a wafer. Light reflected from the features and/or gratings is collected by a measuring system, which processes the collected light. The collected light is indicative of the dimensions achieved at respective portions of the wafer. The measuring system provides trimming related data to a processor that determines the acceptability of the trimming of the respective portions of the wafer. The system also includes one or more trimming devices, each such device corresponding to a portion of the wafer and providing for the trimming thereof. The processor selectively controls the trimming devices to regulate trimming of the portions of the wafer.