METHOD OF WET ETCHING FOR THERMAL OXIDE

摘要

The wet etching method improves the step coverage of various thin films by using BHF solution with a little amount of ethyl alcohol. The method comprises (A) priming hexamethyldisilazane for five minutes on the thermal oxide (2); (B) spreading the positive photoresist (5) and soft baking and, then hard baking; (C) etching the thermal oxide (2) by using BHF solution with ethanol.