微機電元件的製作、模擬與量測

Abstract

本論文呈獻了微機電元件微縮後的共振行為之探討。我們設計了兩種形式的微機電懸臂樑，其結構分別為「單邊固定」及「雙邊固定」，並以砷化鎵基板發展了無底切元件的製作方式。藉由商業模擬軟體ANSYS，我們考慮製程所造成之不完美的情況下，模擬了兩種結構個別的共振頻率，並與實驗結果相互比較之。我們使用了隸屬於國家晶片中心的雷射都普勒震動儀，來量測不同氣壓下懸臂樑的共振頻譜，在氣壓為5 Pa的條件下，單邊及雙邊固定懸臂樑得到的最高之品質因子，分別為4000以及500。同時，我們也進行了變壓力的品質因子量測以及其討論。此外，在雙邊固定懸臂樑上我們觀測到了多模態共振現象，且於兩種結構下發現了不同的非線性行為，最後，我們將結果比較其理論模型並討論之。

This thesis presents the study on the resonant behavior of the shrunken devices of micro-electromechanical system (MEMS). We design two types of MEMS suspending beam, “cantilever and double-clamped beams”. We have developed a fabrication process for making the undercut-free devices on GaAs substrate. By using the commercial software ANSYS, the resonant frequency of the individual structure considering imperfection caused by the fabrication process has been simulated and compared with the experimental results. To measure the resonant spectrum of suspending beams under various air pressures, the laser doppler vibrometer system at National Chip Implementation Center (CIC) has been used. The highest quality factors (Q) of the cantilever and double-clamped beams are about 4000 and 500 at pressure of 5 Pa, respectively. The pressure dependence of Q values has been measured and discussed. Moreover, the multi-mode vibration of double-clamped beams and different non-linear behavior in the individual structure have been observed, discussed and compared with the theoretical models.