COMPOSITION OF SELECTIVE ETCHING SOLUTIONS FOR SILICON OXIDE FILM

摘要

An etchant composition is provided to etch a silicon oxide layer selectively with the control of etching velocity and the decrease of etching loss of other layers when a silicon oxide layer and a nitride layer or a titanite layer on a wafer are exposed simultaneously. An etchant composition comprises 1-40 wt% of ammonium fluoride(NH4F); 1-60 wt% of an organic acid; optionally 0.001-1 wt% of a surfactant; optionally 1-30 wt% of an organic solvent; and the balance of water. Preferably the organic acid is at least one selected from the group consisting of C1-C20 carboxylic acids; and the surfactant is a fluorine-based nonionic surfactant or an anionic surfactant. More preferably the organic acid is at least one selected from glycolic acid, acetic acid, lactic acid, gluconic acid and formic acid.