Organic contaminants removal using UV/O3 and ECR oxygen plasma cleaning techique

초록

We report our experimental results on the removal of the organic contaminants existing on the surface of silicon wafers by a dry cleaning method using UV/O3 and ECR plasma. After cleaning, Si wafers were characterized by Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Atomic Force Microscropy (AFM). In UV/O3 cleaning, the UV/O3 exposure time to reach the detection limit for organic contaminants in ATR-FTIR was about 10 min and the RMS surface roughness reduced with increasing exposure time. In ECR oxygen plasma cleaning, the plasma exposure times to reach both the detection limit and the lowest RMS roughness were 40 and 10 sec, respectively and the optimum plasma exposure time is suggested to be 30∼40 sec, considering both the effects of cleaning and surface roughening. Therefore, dry cleaning using ECR oxygen plasma seems to be more effective than that using the UV/O3 cleaning for the removal of organic contaminants. Also, the removal mechanisms of organic contaminants in UV/O3 and ECR plasma cleanings are discussed in detail