Quantitative Analysis of Damage Depth in Highly Selective Etching and Cleaning Processes for Spacer Nitride Preservation
ABSTRACT
In advanced device integration, highly selective etching and post-etch cleaning are essential processes, as spacer nitride films serve as critical stop layers and electrical isolation barriers. As device geometries become smaller and the margins for contact formation narrow, even minor disruptions—on the scale of nanometers—in spacer integrity can result in leakage paths, short circuits, and a collapse of the process window. This study introduces a quantitative approach for measuring and interpreting the depth of near-surface damage in silicon nitride, which is caused by typical plasma strip/ash chemistries and ion implantation procedures. The measured damage is then correlated with the sensitivity of the material to subsequent wet-clean steps. The goal is to support data-driven decisions in selecting strip and clean conditions that protect spacer nitride, while ensuring effective oxide removal and maintaining overall manufacturability.
BIOGRAPHY
Chong‑Zan (Manny) Wu is an advanced wet process engineer with nearly ten years of experience in semiconductor manufacturing, specializing in wet cleaning, vapor etch, and copper electroplating processes for advanced DRAM technologies.
He currently focus on advanced technology DRAM development and high‑volume manufacturing, focusing on self‑aligned contact cleaning, spacer nitride preservation, interface damage reduction, and process margin enhancement. His work emphasizes translating surface chemistry fundamentals into manufacturable and scalable wet process solutions.
Manny has led and contributed to multiple first‑of‑a‑kind (FOAK) tool evaluations and process integrations, including spin clean, vapor etch, and copper electroplating platforms. Through quantitative analysis and systematic experimentation, his projects have delivered improvements in linewidth roughness, defectivity control, profile uniformity, process simplification and cycle time reduction.
With extensive experience in cross‑fab technology transfer, Manny has supported long‑term overseas assignments in Japan and the United States, collaborating closely with equipment suppliers, R&D teams, and manufacturing organizations. He is recognized for bridging detailed process physics with practical manufacturing execution.
He is an active contributor to technical innovation, having authored multiple technical posters on contact clean optimization, nitride damage characterization, and wet etch enablement, and is an inventor on several patent filings related to wet process profile control and interface engineering. In addition, Manny is committed to knowledge sharing and engineering development, regularly delivering structured technical training for early‑career engineers.