Method of analyzing silicon groove damage using QSS-PC, PL imaging, silicon etch rate, and visual microscopy for solar cell fabrication

摘要

This work uses a variety of tools to investigate damage caused by laser and dicing saw grooving in silicon. The tools comprise quasi steady state photoconductance decay, photoluminescence imaging, measurement of silicon etch rate in anisotropic etch solution, and visual microscopy. Shallow grooves were formed using a 532 nm Q-switched Nd:YLF frequency doubled solid state laser and a high speed spindle dicing saw. Combined analysis of the characterization tools enabled determination of the damage radius of the grooves within the bulk of the wafer, the radius of damage in the dielectric layer laterally along the surface of the wafer, as well as the groove etching requirements to fully recover the minority carrier lifetime in the vicinity of the groove.