臺灣博碩士論文加值系統

本研究使用TSMC 0.35um Mixed Signal 2P4M Polycide製程並搭配後製程，設計開發一個降低結構變形量CMOS-MEMS全差分電容式加速度計。以CMOS-MEMS製作的加速度計，一般都會受到殘餘應力影響，有嚴重的翹曲現象，本研究欲藉由降低殘餘應力的方式，來降低結構降曲量，最大特色為提出預先在結構最下方內埋多晶矽層，使用傳統乾蝕刻加速度計一樣的製程方式，並於製程最後將其蝕刻去除，連帶去除多晶矽下方殘留應力最大的場氧化矽層(Field oxide, FOX)，以降低結構翹曲量，整體元件性能整理如下：(1)CMOS-MEMS技術，單晶整合機械結構與感測電路，(2)全差分感測架構，可以放大感測訊號並消除共模雜訊，(3)利用蝕刻掉下方多晶矽層，降低結構翹曲量。

This study utilize TSMC 0.35um Mixed Signal 2P4M Polycide process and post process to design and fabricate a reduced structure deflection capacitive type fully differential CMOS-MEMS accelerometer. In general, accelerometer fabricated with CMOS-MEMS process face issue of severe deflection due to residual stress. The merit of this study is to etch away polysilicon which is embedded in the bottom part of structure at the end of process, which is the same as traditional dry etching process. Field oxide(FOX), which contribute highest level of residual stress, is then be removed simultaneously. Deflection of structure can be reduced thereof. Overall characterization of the device is: (1) integrate MEMS and IC monolithically with CMOS-MEMS technique, (2) amplify sensing signal and eliminate common mode noise through fully differential sensing, and (3) etch away polysilicon under the structure to reduce deflection.

目錄
摘要.............................................................................................................I
Abstract .................................................................................................. II
目錄.........................................................................................................III
圖目錄......................................................................................................V
表目錄..................................................................................................... IX
符號表.......................................................................................................X
第一章 緒論............................................................................................1
1-1 前言..............................................................................................1
1-2 研究動機......................................................................................2
1-3 研究目標......................................................................................4
第二章 文獻回顧..................................................................................11
2-1 CMOS-MEMS製程...................................................................11
2-2 加速度感測機制........................................................................13
2-3 電容式加速度計........................................................................15
第三章 元件設計與分析......................................................................33
3-1 電容式感測模型........................................................................33
3-2 結構設計 ................................................................................36
3-2.1 質量塊與彈簧設計............................................................37
3-2.2 共振頻模擬........................................................................38
3-2.3 電容變化量模擬................................................................38
3-2.4 結構變形模擬....................................................................39
3-3 懸浮測試結構............................................................................40
第四章 光罩佈局與後製程結果..........................................................50
4-1 光罩佈局....................................................................................50
4-2 後製程結果................................................................................51
第五章 元件量測結果與討論..............................................................62
5-1 結構量測....................................................................................62
5-2 動態頻率響應量測....................................................................63
5-3 輸出量測....................................................................................64
第六章 結論與未來工作..............................................................75
6-1 結論............................................................................................75
6-2 未來工作....................................................................................76
參考文獻..................................................................................................77

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