METHOD OF MEASURING ETCHING CONDITION OF SEMICONDUCTOR WAFER

摘要

PROBLEM TO BE SOLVED: To provide a method of measuring an etching condition of a wafer. SOLUTION: A wafer subjected to an excessive plasma etching process is irradiated with light in a specified wavelength range. From electric signals corresponding to light reflected from the wafer, specified optical impedances 1, 2 are obtained. The optical impedance 1 is compared with a specified reference impedance to determine whether an excessive etching process for the wafer is completed or not. When the process is completed, a wafer film is measured using a recipe wherein a specified excessive etching completed film stack is applied. When the process is not completed, the optical impedance 2 is compared with another specified reference impedance to determine whether the excessive etching process for the wafer is completed or not. When the process is completed, the wafer film is measured using a recipe wherein the specified excessive etching completed film stack is applied. When the process is not completed, the wafer film is measured using a recipe wherein a specified excessive etching uncompleted film stack is applied.