Electrical failure analysis using SEM Automated Process Inspection (API) System

Abstract

The introduction of automated process inspection (API) system using in-line SEMVision was applied to monitor the contact process of the inter layer dielectric (ILD). The conventional optical inspection systems do not have enough resolution to monitor ILD contact etching when the technology has scaled down to the deep submicron node from the submicron. In semiconductor process, the contact process of the ILD is one of the most critical processes. Usually, in-line E-beam system is used in monitoring the contact process or to detect device leakage. The Off-line uses TEM to check contact etching with a physical failure analysis [1]. Low throughput is the main disadvantage in both E-beam and TEM inspections, especially the physical analysis of TEM, which needs more than 2~3 days due to the complex sample preparation. In order to shorten the inspection time of the E-beam, we developed a novel mode of a rapid auto process inspection system using inline SEMVision, this can effectively detect contact processing issues.