SURFACE CLEANING METHOD WITH ISOTROPIC ETCHING FOR TEXTURED SILICON WAFERS

摘要

The present invention provides a chemical surface cleaning method for textured crystalline silicon wafers, obtained by modifying a standard chemical cleaning method, RCA. In the method according to the invention, chemical cleaning comprises isotropic etching in CP4 etch, followed by immersion of the silicon wafers in the RCA-2 solution. Planarisation increases chemical gettering and does not alter the structure of the micropyramids, since immersion time is short and controlled, of preferably only 10 seconds. Among other technical advantages, the method according to the invention increases by at least 175% the minority carrier lifetime and decreases processing time by approximately 9 minutes.