Reduction of FIB induced damage in silicon with Argon sputter clean

Abstract

Focused ion beam (FIB) technique has been widely used in Si base semiconductor for cross sectioning sample preparation to a scale of nanometers accuracy. As FIB involve removing material with high ion energy, inevitably damage will be induced on the sample surface. This paper addresses the effect of FIB induced damage in silicon for junction staining and poly silicon profile delineation application. This damage will prevent junction stain chemical mixture to effectively stained out the P-type and N-type implantation. Additionally, it also caused damage on poly silicon and silicon substrate after buffered oxide etch (BOE) staining on FIB prepared cross sectioning samples. The effectiveness of argon sputter clean on FIB induced damage reduction has been studied with different duration. Successful junction stain result and wet chemical delineation of poly silicon profile on FIB prepared sample were achieved with optimized Argon sputter clean timing.