Etching solution for removal of oxide film, method for preparing the same, and method of fabricating semiconductor device

Abstract

Provided are an anionic surfactant-containing etching solution for removal of an oxide film, preparation methods thereof, and methods of fabricating a semiconductor device using the etching solution. The etching solution includes a hydrofluoric acid (HF), deionized water, and an anionic surfactant. The anionic surfactant is a compound in which an anime salt is added as a counter ion, as represented by R1—OSO3−HA+, R1—CO2−HA+,R1—PO42—(HA+)2,(R1)2—PO4—HA+, or R1—SO3—HA+ where R1 is a straight or branched hydrocarbon group of C4 to C22 and A is ammonia or amine. The etching solution provides a high etching selectivity ratio of an oxide film to a nitride film or a polysilicon film. Therefore, in a semiconductor device fabrication process such as a STI device isolation process or a capacitor formation process, when an oxide film is exposed together with a nitride film or a polysilicon film, the etching solution can be efficiently used in selectively removing only the oxide film.

Dependencies are inferred from the claim text.