用于MEMS开关的低应力氮氧化硅桥膜

Low-stress Silicon Oxynitride Bridge Used for MEMS Switch

给出了用于微机电(MEMS)开关悬浮桥的低应力氮氧化硅(SiOxNy)薄膜的制备工艺研究结果,分析了等离子增强化学气相淀积(PECVD)制备低应力薄膜的影响因素,通过改变反应气体(SiH4,NH3和N2O)的流量比,用PECVD方法生成系列SiOxNy薄膜样品。利用形貌仪测量样品的曲率半径,计算相应的应力。研究表明,当反应气体(SiH4,NH3和N2O)的流量比为32∶12∶8(N2标定)时,可以得到张应力值为76.8 MPa的SiOxNy薄膜,其折射率为1.688,Si,N和O三种元素的成分比为56.3∶23.7∶20.0。将此薄膜生长工艺应用于开关制备,得到了适用于DC^10 GHz频段的MEMS接触式开关,其驱动电压为23.3 V。

Low-stress silicon oxynitride (SiOxNy) films used for the switches of the micro-electronic-mechanics system (MEMS) switch were prepared by plasma enhanced chemical vapor deposition (PECVD). After the impact factors of deposition of low-stress films by PECVD were analyzed, a series of SiOxNy film samples were prepared using SiH4/NH3/N2O at different gas flux ratios. The curvature radius of the samples was measured by a profiler and the stress corresponding to the films was calculated. The results show that the SiOxNy film with a low tensile stress of 76.8 MPa can be obtained when the gas flux ratio is 32:12:8 (SiH4:NH3:N2O), its refractive index is 1.688, and its chemical component ratio (Si:N:O) is 56.3:23.7:20.0. When the deposition condition was used to prepare the switch, a MEMS contact switch can be obtained, which it can be applied in a frequency range of DC-10 GHz and its driving voltage is 23.3 V.