Monitoring quality parameters in standard cleaning baths – Measure ammonium hydroxide, hydrogen peroxide, and hydrochloric acid simultaneously with inline analysis

Silicon semiconductor devices are manufactured on highly polished wafers. Surface preparation is a key step to obtain clean, mirror polished, undamaged silicon surfaces.

 

The most common chemical cleaning process, «RCA clean», is a proven method used here to remove contaminants from the wafer surface via two consecutive standard bath solutions. The key factors for efficient wafer cleaning are bath residence time and optimum chemical concentration in the cleaning baths. Rapid inline monitoring of the major SC1/SC2 bath constituents guarantees increased wafer yields while decreasing defect density.