A Study on Process Diagnosis Technology to Improve the Reliability of the Etching Process

Abstract

With the increasing demand for semifductors in various fields, productivity efficiency is emerging as an important issue in semiconductor device manufacturing. To maximize semi-conductor productivity, the semiconductor process must be monitored in real time to continuously reflect the results and utilize them for process stabilization. However, various unexpected variables that occur during the process and errors in their judgment may cause a significant loss in semiconductor productivity. In this study, basic research was conducted on the concept of a diagnostic sensor capable of monitoring the etch amount by changing the surface resistance of a thin film according to the process. In various etching processes, a change in the surface resistance was observed according to the change in the thickness of the thin film, and the correlation between the change in thickness and the change in the physical quantity was studied. The trend of the overall measured values showed linearity. Based on the linear change in the etch amount and surface resistance according to the cycle change, the change in surface resistance according to the etch amount was quantitatively calculated. For the reliability of measurement, the thickness was compared using SEM and an el-lipsometer, and both investigated a thickness of 304 nm.