화학공학소재연구정보센터
Journal of the Electrochemical Society, Vol.146, No.12, 4485-4489, 1999
Alternatives to hydrogen fluoride for photoelectrochemical etching of silicon
Photoelectrochemical etching of silicon in nonaqueous solutions without the use of free-fluoride or HF has been demonstrated. Silicon was electrochemically oxidized and dissolved using stable, fluoride containing salts in acetonitrile solutions. The current-voltage behavior of silicon in acetonitrile solutions containing tetrabutylammonium tetrafluoroborate or tetrabutylammonium hexafluorophosphate were similar. The voltammetry of silicon in solutions containing tetrabutylammonium trifluoromethylsulfonyl, potassium hexafluoroarsenate, or sodium hexafluoroantimonate showed large hysteresis indicating the presence of silicon oxide on the surface. Although the dissolution rate of silicon dioxide was negligible in the absence of free-fluoride or HF the oxidation and dissolution of silicon could be maintained, even when thin oxides were formed. Photocurrent oscillations associated with the buildup and removal of oxides were observed when traces of water were present.