APCVD doped oxides used as etch mask in KOH solution

Abstract

This paper presents a study of APCVD doped oxides deposited on silicon substrate. Films of silicon dioxide, phosphosilicate, borosilicate, borophosphosilicate glass with different content of phosphorus and boron were studied as masks for etching in KOH solution. The experiments draw the conclusion that the best film is densified borophosphosilicate glass with 4 wt% P and 23 wt.% B. Also, good results were obtained for densified borosilicate glass. The densification treatment used is compatible with the aluminium metallisation process.