Surface Damage by Physical Cleans during Semiconductors Manufacturing

Abstract

This paper investigates surface damage caused by physical cleaning processes during semiconductor manufacturing. The study focuses on various materials, including FDSOI wafers and polymer films, subjected to high-velocity sprays and cryogenic cleans. Thanks to the supplier process performances and quality control, FDSOI films do not present any specific concern linked with this failure mode. This latter can be observed on whatever films exposed to aggressive physical cleans and the wafers are cleverly used as a test vehicle to evidence surface defects with a revelation method using a wet etchant. It enables the detection of nano-cracks and other damages. Same defects are observed in bulk silicon wafers, and solutions exist to avoid these damages. Different spray types are compared, highlighting the impact of droplet energy distribution on surface integrity. Additionally, a direct characterization method using polymer films is developed to assess physical cleaning damage. The findings emphasize the importance of optimizing cleaning processes to balance defect removal efficiency and surface preservation. Emerging cleaning solutions like polymer coat and peel methods are also discussed for their potential to offer high cleaning performance with minimal surface damage.