Monitoring and Optimization of Silicon Surface Quality

Abstract

We have used contactless photoconductance decay measurements to monitor cleaning processes, surface contamination, and surface roughness. Changes in surface chemistry are evidenced by a degradation (increase) in the surface recombination velocity (decrease in measured decay time). We have applied the tool to monitor cleaning effectiveness, surface cleanliness, and roughness during cell processing. Iodine in methanol achieves a superior passivation of Si than H in 48%. The measured minority carrier lifetime in this solution is higher than in 48% . We illustrate that I‐terminated silicon surfaces are more stable than H‐terminated surfaces. We confirm that deionized water is responsible for the roughening of silicon surfaces. We show that is a superior alternate clean to dilute .