Y. Shiramizu et al., REMOVAL OF METAL AND ORGANIC CONTAMINANTS FROM SILICON SUBSTRATES USING ELECTROLYSIS-IONIZED WATER CONTAINING AMMONIUM-CHLORIDE, Journal of the Electrochemical Society, 143(5), 1996, pp. 1632-1635
The efficiency of removing metal and organic contaminants from silicon
substrate surfaces by using electrolysis-ionized water containing amm
onium chloride was compared with the removal efficiency using an ammon
ium hydroxide and hydrogen peroxide mixture and a hydrochloric acid an
d hydrogen peroxide mixture. Before and after wet cleaning, metal impu
rities were measured using hydrofluoric acid vapor-phase decomposition
atomic absorption spectrometry, and the organic impurities were measu
red using thermal desorption spectroscopy gas chromatography mass spec
trometry. The electrolysis anode water removed both metal and organic
contaminants due to its high oxidation-reduction potential and low pH.
Oxidation and oxidative degradation are effective for the removal of
both metal and organic contaminants from silicon substrate surfaces, a
nd metallic complex acids are stable at low pH of the electrolysis ano
de water. The electrolysis cathode water, on the other hand, cannot re
move metal or organic contaminants because of its high pH and low oxid
ation-reduction potential.