WET ETCHING METHOD OF SEMICONDUCTOR DEVICE

摘要

This method comprises (1) coating photoresist on the silicon oxide film on silicon and (2) etching the silicon oxide film by photomask. The above etching method comprises (A) first etching with BHF photoresistive solution and (B) second etching with PAD photoresistive solution to etch the edge of sharp profile pattern formed by the first etching, into smooth profile pattern. The photoresistive solution, BHF and PAD, have different etching ratio. The BHF is mixed with NHF4 and HF at the ratio of 6:1 or 10:1, and the PAD is mixed with NH4H, DI water and CH3COOH at the ratio of 2:1:2.