Frequency response of a new kind of silicon nanoelectromechanical systems resonators  

一种新型纳机电硅谐振器的频率响应特性(英文)

作　　者：于虹[1] 袁为民[1] 刘春胜[1] 岳东旭[1] 吴士杰[1] 顾勇[1] 陈志远[1] 黄庆安[1] 

机构地区：[1]东南大学MEMS教育部重点实验室,南京210096

出　　处：《Journal of Southeast University(English Edition)》2012年第3期310-314,共5页东南大学学报（英文版）

基　　金：The National High Technology Research and Development Program of China(863 Program)(No.2007AA04Z301)

摘　　要：Diffraction effects will bring about more difficulties in actuating resonators,which are electrostatically actuated ones with sub-micrometer or nanometer dimensions,and in detecting the frequency of the resonator by optical detection.To avoid the effects of diffraction,a new type of nanoelectromechanical systems（NEMS） resonators is fabricated and actuated to oscillate.As a comparison,a doubly clamped silicon beam is also fabricated and studied.The smallest width and thickness of the resonators are 180 and 200 nm,respectively.The mechanical oscillation responses of these two kinds of resonators are studied experimentally.Results show that the resonant frequencies are from 6.8 to 20 MHz,much lower than the theoretical values.Based on the simulation,it is found that over-etching is one of the important factors which results in lower frequencies than the theoretical values.It is also found that the difference between resonance frequencies of two types of resonators decreases with the increase in beam length.The quality factor is improved greatly by lowering the pressure in the sample chamber at room temperature.对于静电驱动的亚微米及纳米尺度的谐振器,衍射效应将会使其驱动及振动频率的光学检测变得更加困难,为克服衍射效应的影响,设计、制作了新型纳机电谐振梁——H型梁,使其产生高频振荡.并制作了双端固支谐振器以进行比较.2种谐振梁的最小宽度和厚度分别为180和200nm.对这2种结构的机械振动特性进行了实验研究.谐振器的基波振荡频率在6.8～20MHz之间,远低于理论预估值.通过模拟仿真发现,过腐蚀是导致振动频率低于理论值的重要原因之一.实验还发现:2种谐振器的谐振频率之差随着梁的长度增加而下降;在室温下减小样品腔的压强后,谐振器的品质因数可以大大提高.

关 键 词：nanoelectromechanical system resonant frequency over-etching nano-beam 

分 类 号：TP212.13[自动化与计算机技术—检测技术与自动化装置]