Etching of silicon nitride

A method for etching silicon nitride which comprises contacting an article containing said silicon nitride and a silicon dioxide with an etching composition containing about 0.1 to about 3 molar of a fluoride containing compound, an organic solvent, wherein said solvent is selected from the group consisting of propylene carbonate, N-methyl pyrrolidone, gamma butyrolactone, methylene chloride, benzyl alcohol, N-formyl morpholine, N-formyl piperidine, cyclohexanone, cyclopentanone, methyl benzoate, diglyme, 2-methyl tetrahydrofuran, methyl and ethyl esters of acid selected from the group consisting of phthalic acid, isophthalic acid and terephthalic acid and about 0.1 to about 4 molar water to thereby etch said silicon nitride at a rate at least as fast as that for said silicon dioxide.