Experimental Study on Etching Characteristics of a Spin-Etching Method

Abstract—In this paper, a spin-etching method is proposed for wafer thinning using a mixture of hydrofluoric, nitric, and acetic acids (HNA solution), and experimental studies are conducted. In the spin-etching apparatus, the silicon wafer was rotated in a Teflon bath filled with HNA solution. The etch rate of HNA spin-etching can be determined by mixture ratio; mass transfer, both through an…