One-chamber workflow for STEM examination of EBIRCH-localized defects : YE: Yield Enhancement/Learning

A workflow for efficient analysis of defects in an SRAM array is proposed. After delayering, the transistors responsible for a specific single cell failure are localized using a nanoprobing system loaded into a dual-beam FIB chamber. The failing area is analyzed by the nanoprobing system with the EBIRCH (Electron Beam Induced Resistance CHange) technique. Then a high-resolution backscatter image is undertaken to look in-plane for certain types of defects. This is followed by the preparation of a TEM lamella inside the same chamber. The analysis is preceded by the use of a STEM detector to take high-resolution cross-sectional images of the defect. Rotated views of the specimen may then be taken to form a 3D tomographic image. The proposed workflow makes optimum use of a single chamber analytical tool. Example images from a recent analysis performed on 14 nm bulk technology sample are provided.