Study of Under Etching Characters of Si(100) in Surfactant Added TMAH

摘要

Our research focuses on the etching characteristic of (100) silicon wafer in surfactant added tetramethyl -ammonium-hydroxide (TMAH:( CH3)4NOH)) solution. The experimental result shows that under etching effect in TMAH achieved a significant reduction by adding fatty alcohol ethoxylate (R-O (CH2-CH2)n-OH) in the solution. Synperonic-A series fatty-alcohol-ethoxylate with increasing length of ethylene oxide segments,Synperonic-A7, A11 were used to carry out the experiment. The maximum under etching rate achieves a reduction up to three quarters. The etching loss of convex is negligible for medium depth etching from 0 to30μm.