Smart optical measurement probe for autonomously detecting nano-defects on bare semiconductor wafer surface: highly sensitive observation system using phase-contrast microscopy with a spatial light modulator

Abstract

Nowadays, the yield rate of semiconductor process is strongly affected even by nanoscale defects on bare Si wafer surfaces. Therefore, a non-destructive and high-speed method for detection of nanoparticle contamination is highly demanded. In this research, a nanoparticle detection method is proposed based on the fact that the volatilization process of the volatile inert liquid behaves as an autonomous nanoparticle search probe. Dynamic phase contrast microscopy (Dynamic PCM) is proposed to detect small thickness changes of a thin liquid film with high sensitivity. The dynamic PCM is expected to have double sensitivity compared to normal PCM and it is experimentally verified. Based on previous results, 4% intensity change is expected for 10 nm particles and even over 1.5% intensity change is expected for 5 nm particles by using this proposed dynamic PCM.