TMAH硅湿法刻蚀剂中异丙醇与氧化剂的协同作用

Synergistic Effect of Isopropyl Alcohol and Oxidant in Silicon Wet Etching with TMAH Etchant

四甲基氢氧化铵(TMAH)是一种在微机电系统加工中常用的硅湿法刻蚀剂。在对含有铝结构表面的硅器件进行湿法刻蚀时,需要在TMAH溶液中添加一定量的硅酸和氧化剂,以保护器件表面的金属铝,但这会降低硅表面的光洁度。本文在含硅酸的TMAH溶液中同时添加过硫酸铵和异丙醇2种物质,研究其对TMAH刻蚀作用的影响。研究结果表明,2种物质的协同作用能够显著提高硅刻蚀表面的光洁度。

Tetramethyl ammonium hydroxide （TMAH） is a kind of silicon wet etchants frequently usedin Micro-electromechanical Systems （MEMS）. When etching a silicon device with aluminum structure onits surface, for protecting the aluminum structure, a quantity of silicic acid and oxidant are added intothe TMAH solution, but doing so will result in the decline of surface smoothness. In this paper, twokinds of substance, isopropyl alcohol （IPA） and ammonium persulfate （AP） are simultaneously addedinto the TMAH solution in which silicic acid is resolved beforehand, and the effect on the etching per-formance of TMAH is studied. Result of the research reveals, the synergistic effect of IPA and AP canimprove the smoothness of silicon etching surface remarkably.