Electrochemical characterization of Si in tetra-methyl ammonium hydroxide (TMAH) and TMAH:Triton-X-100 solutions under white light effects

Abstract

An experimental study of the electrochemical characteristics of the silicon/tetra-methyl ammonium hydroxide (TMAH) junction under dark and white light conditions are investigated for both n- and p-type Si. The presence of Triton-X-100 (TX100) in the TMAH solution under white light conditions is also studied. Cyclic voltammetry (CV) and ex situ atomic force microscopy (AFM) are employed to study the white light effects on the etching characteristics of silicon in TMAH and TMAH:TX100. It was found that the passivation peak potential shifted significantly for both n- and p-type Si under white light conditions. The positions of the flatband potential for n- and p-type Si were predicted by CV under illumination. Finally, etch rate studies and preliminary surface roughness measurements were performed on p(100) Si in TMAH under both dark and white light conditions. These latter studies concluded that a reduction in the vertical surface roughness occurred in the presence of white light.