Non-Visual Defect Identification by Dopant Analysis Method in FinFET Devices

Abstract

For a specific IDDQ failure only around SRAM cell boundary, we conducted a systematic investigation in the lab involving electrical, physical, and chemical analysis. Following electrical test locating the failure area according to PEM (photon emission microscopy) and physical defect analysis resulting in NDF (no defect found), we explored an alternative method to define the failure. In this paper, we demonstrated the success of using tunneling AFM (TUNA) in diagnosing such an IDDQ failure occurring in FinFET devices. AFM (TUNA) analysis was able to visualize clearly the dopant discrepancies in comparison between the IDDQ fail and pass references in FinFET transistors. The dopant abnormalities indicated the current IDDQ fail was caused by processes that impaired the dopant implantation.