Surfactant in TMAH for new shapes of silicon MEMS components; Its orientation dependent adsorption detected by infrared spectroscopy

We have demonstrated the applications of surfactant added TMAH for the formation of new shapes of MEMS components. The research is further extended for in-situ observation of the Si/(TMAH+surfactant) interface during the etching process using Fourier transform infrared microscopy (FT-IR) in the multiple internal reflection (MIR) geometry to detect the selective adsorption of the surfactant on different crystallographic planes. The study is primarily aimed at investigating the causes behind the change in the etching behavior of TMAH solution when the surfactant is added. Silicon wafers with different orientation are used to observe the selective adsorption of the surfactant on their surfaces.