Precision Silicon Exfoliation Tool Design

Abstract

The desire for thin-film silicon is motivated by the growing needs for flexible electronics, compact packaging, and advanced solar power. In previous work we have presented exfoliation as means to a cost effective way to achieve thin-film silicon and described an open loop prototype exfoliation tool that could be used to produce improved films compared to previous methods. However, controllable film thickness, film uniformity, and surface roughness were all challenges with the open loop setup. This paper describes the design, construction, and testing of an improved controlled exfoliation tool with load compensation and inline metrology for closed loop control of the exfoliation process. The exfoliation performance results are compared to those from the proof-of-concept tool and show 53% improvement in silicon uniformity and 67% improvement in average surface roughness. These improvements can be attributed to the addition of load compensation and the improvement in the precision motion of the stage, respectively.