Etch Rates of Doped Oxides in Solutions of Buffered HF

The dependence of the etch rates of vapor‐deposited binary borosilicate, phosphosilicate, and arsenosilicate glasses on glass composition and per cent buffered HF ( 1 part 48 % HF to 10 parts 40 % NH 4 F ) in water are presented. The etch rates of these doped glasses generally increase with increasing dopant oxide concentration, the exception being those of borosilicate glasses in concentrated buffered HF which exhibit minima at about 18 mole per cent (m/o) B 2 O 3 . The use of these and similarly gathered results to infer new etchants is demonstrated.