Application of Auger electron spectroscopy (AES), TEM electron energy loss spectrum (EELS) in failure analysis on poly grooves issue in wafer fabrication

In this paper, a case study on the failure analysis and yield enhancement on poly grooves/divots in wafer fabrication was investigated and studied. Several failure analysis techniques and tools such as SEM, Auger electron spectroscopy (AES) and transmission electron microscopy electron energy loss spectrum (TEM EELS) were used in the course of the failure analysis to understand the root cause/mechanism relating to poly groove issues. The poly grooves occurred on the interface of the P+/N+ poly was due to missing oxide as a result of the resist not removed and caused chemical attack in the subsequent spacer etch.