The silicon etching process in tetramethylammonium hydroxide (TMAH) has been characterized using Raman scattering measurements. The measurements were carried out for 20 and 2% TMAH at different temperatures and for 20% TMAH in situ during the etching process. The Raman peaks due to silicon etching in TMAH agree with the peaks observed in KOH etching and are attributed to silicate and its polymers, suggesting the same dissolution process. The concentration of the silicate polymers appears to increase as the temperature of the solution decreases. The polymer concentration also appears to increase with time during the in situ measurements. Precipitates were observed for the lowered solution temperature. Strong bubbling was observed at the beginning of the in situ measurement.