Behavior Analysis of Si Etching Process with HF/HNO3 Mixture in Single-Spin Wafer Process

Takashi Oinoue; Suguru Saito; Atsushi Okuyama; Yoshiya Hagimoto; Hayato Iwamoto

doi:10.4028/www.scientific.net/SSP.282.83

Paper Titles

Removal of CrN Contamination from EUV Mask Backside Using Dry Cleaning
p.59

Damage-Free Cleaning of Advanced Structure Using Timely Energized Bubble Oscillation Megasonic Technology
p.64

An Observation Method of Real Contact Area during PVA Brush Scrubbing
p.73

Electrostatic Discharge Control and Visualization in Spray Nozzle
p.77

Behavior Analysis of Si Etching Process with HF/HNO₃ Mixture in Single-Spin Wafer Process
p.83

Study of the Anisotropic Wet Etching of Nanoscale Structures in Alkaline Solutions
p.88

Unexpected Pyramid Texturization of n-Type Ge (100) via Electrochemical Etching: Bridging Surface Chemistry and Morphology
p.94

Selective Wet Etching in Fabricating SiGe and Ge Nanowires for Gate-all-Around MOSFETs
p.101

SiGe vs. Si Selective Wet Etching for Si Gate-all-Around
p.107

HomeSolid State PhenomenaSolid State Phenomena Vol. 282Behavior Analysis of Si Etching Process with...

Behavior Analysis of Si Etching Process with HF/HNO₃ Mixture in Single-Spin Wafer Process

Abstract:

The HF/HNO₃ mixture Si etching process is widely used to remove stress and damaged layers after Si wafer back grinding. Although there have been many reports on the dip process, there have been few detailed reports on the single-spin process. In a single spin process, Si etch rate distributions largely differ with different HF/HNO₃ concentrations. On the other hand, thermal SiO₂ etch rate distributions are similar even with different HF/HNO₃ concentrations. In this work, we analyzed Si surfaces with XPS (X-ray Photoelectron Spectroscopy) after processing various HF/HNO₃ mixture concentrations. SiO_x stays steady in any wafer position and HNO₃ concentration, whereas SiO₂ thickens depending on HNO₃ concentration at the center. We assumed that Si etch rate distributions were caused by HF or HNO₃ consumption and confirmed this assumption was correct in a wafer center SiN cover experiment.