Plasma-enhanced atomic layer deposition of silicon nitride for front-end-of-line applications

Abstract

SiN deposition at low temperatures using the plasma-enhanced atomic layer deposition (PEALD) process is gaining momentum. A high-quality SiN layer deposited using a lower thermal budget and low wet etch rates are desired for front-end-of-line applications in semiconductor industries. In this study, deposition of PEALD SiN is investigated by utilizing a highly reactive trisilylamine silicon precursor and three different reaction partners for a nitrogen precursor. The quality of PEALD SiN layers is compared with the reference standard, low-pressure chemical vapor deposition SiN layers. The properties of different SiN layers are interpreted using FTIR and XPS material characterization techniques. Furthermore, the wet etch rates of as-deposited and annealed PEALD SiN layers are investigated. Finally, the conformality of PEALD SiN layers is assessed in trench and horizontal high aspect ratio structures.