摘要 |
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 R<SUB>1</SUB>-OSO<SUB>3</SUB><SUP>-</SUP>HA<SUP>+</SUP>, R<SUB>1</SUB>-CO<SUB>2</SUB><SUP>-</SUP>HA<SUP>+</SUP>, R<SUB>1</SUB>-PO<SUB>4</SUB><SUP>2-</SUP>(HA<SUP>+</SUP>)<SUB>2</SUB>, (R<SUB>1</SUB>)<SUB>2</SUB>-PO<SUB>4</SUB><SUP>-</SUP>HA<SUP>+</SUP>, or R<SUB>1</SUB>-SO<SUB>3</SUB><SUP>-</SUP>HA<SUP>+</SUP> where R<SUB>1 </SUB>is a straight or branched hydrocarbon group of C<SUB>4 </SUB>to C<SUB>22 </SUB>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.
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