高机械灵敏度悬空导电薄膜的制备方法研究

微机电系统中的悬空薄膜的制备技术是微结构制备的关键技术之一.研究了周边固支方形薄膜的机械灵敏度及通过浓硼扩散自停止腐蚀法制备高灵敏度悬空导电薄膜.实验结果表明,当扩散温度为1 175℃,扩散时间为3h,去除硼硅玻璃后四甲基氢氧化铵(TMAH)腐蚀液中腐蚀7.5h,可得到厚度为3μm,边长为5 mm,方块电阻为1.12 Ω/sq,致密均匀的悬空导电薄膜.给出了详细的制备工艺；针对扩散过程中出现的硼硅玻璃等问题,给出了切实可行的解决办法.

Research on the Preparation Method of Free-handing Conductive Membrane with High Mechanical Sensitivity

The preparation method of the free-handing film in MEMS is one of the key technologies of micro structure preparation.This article focuses on the mechanical sensitivity of peripheral fixed supported square film and introduces how to fabricate highly sensitive free-handing film by adopting the deep boron-diffusion self-stopped etching technique.The experiment shows that when the silicon was diffused for 3 h at a temperature of 1 175 ℃ and then,after removing the borosilicate glass covering it,was etched in TMAH for 7.5 h,an even free-handing film which is 3 μm in thickness,5 mm in length and 1.12 Ω/sq in sheet resistance was fabricated.The article provides a detailed introduction to the preparation method of the free-handing film and proposes some feasible solutions to solve the problem of borosilicate glass that appears during the process of diffusion.