硅微机械音叉式谐振器  

Silicon Micromachined Tuning Fork Resonator

作　　者：钟莹[1] 张国雄[1] 郝一龙[2] 贾玉斌[2] 

机构地区：[1]天津大学精密测试技术与仪器国家重点实验室,天津300072 [2]北京大学微电子学研究所,北京100871

出　　处：《仪器仪表学报》2005年第8期782-785,共4页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金项目(50275108)资助。

摘　　要：应用体硅微机械加工技术,制作了一种双端固定音叉式谐振器。它在音叉的两个臂上连接了梳齿电容结构,用来驱动音叉臂在硅片平面内侧向、反相振动,同时检测音叉的振动频率。当驱动力的频率等于音叉的固有频率时,音叉产生谐振。此时,检测梳齿电容输出的电流最大。用有限元方法对谐振器进行了模态分析和结构优化。音叉臂长800μm,宽5μm,梳齿电容齿长25μm,结构层厚度为80μm,在30V交流电压激励下,测得其谐振频率为25kHz。当音叉受到轴向力的作用时,音叉的固有频率会发生变化,根据这一原理,设计了谐振式加速度计。用有限元分析软件对加速度计工作情况仿真,估算其灵敏度约为2Hz/g。这种音叉式谐振器结构和工艺简单,性能可靠,成本较低,对于进一步研究微机电系统谐振器件具有重要意义。A double-ended tuning fork resonator is presented,which is fabricated by silicon bulk micromachining technology. Electrostatic combs,exciting the tines to vibrate laterally in antiphase in the plane of the wafer,and detecting the vibrating frequency in the meantime,are mounted on the two tines of fork. If the driving frequency coincides with the tine＇s natural frequency,the fork would resonate,and the output current of the sensing combs would reach to a maxim. Finite element method is used to analyze the vibratory modes and optimize the structure. The whole structure is 80μm thick,and the tines are 800μm long,5μm wide,with comb fingers 25μm long. Giving the driving voltage of 30V,the fork＇s resonant frequency is measured to be 25kHz. When an axial force is applied on the fork ,there is a shift in its natural frequency. Based on this principle,a resonant accelerometer is designed. According to the simulation by finite element analysis software,the sensitivity of the accelerometer is about 2 Hz/g. This resonator takes advantages of simple structure and process flow,high reliability and low cost, which is crucial for further investigation of MEMS resonant devices.

关 键 词：微机电系统 音叉 谐振器 加速度计 体硅工艺 

分 类 号：TN216[电子电信—物理电子学]