臺灣博碩士論文加值系統

本研究主要針對體型微加工之壓阻式微壓力感測器進行研究，藉由微機電軟體以及有限元素模擬軟體之間的相互配合，減少模型建立時程以及快速的進行其模擬結果之驗證，並對壓力感測器做結構之最佳化設計。
在模擬方面，比較薄膜面積200*200μm及400*400μm之電阻值的變化以及薄膜與實體之間靈敏度的差異。根據結果所示，薄膜面積400*400μm所產生的電阻變化率相較於200*200μm增加約4.79倍，而薄膜相對於實體之靈敏度約可高出近30%。在製程方面，利用n-type矽晶片上設計出一長50μm、寬10μm之離子佈植開孔而後植入硼離子，依其設計和目的約佈植6*1013cm-2之濃度及佈植能量30eV以當成壓電阻，再於背向矽晶片上蝕刻出薄膜結構，其面積為200*200μm及400*400μm兩種，並測試各種KOH濃度20%、30%、40%以及溫度50℃、60℃、70℃、80℃、90℃不同之蝕刻條件，再以SEM及AFM來檢測和控制蝕刻率及薄膜品質，結果發現在KOH濃度30%及加熱溫度80℃時有較佳的表面平坦度。而後分別設計15μm、25μm、50μm三種膜厚來比較出靈敏度變化量。利用E-beam蒸鍍的方法在矽晶片正面沈積金來當導線並連接佈局成惠司敦電橋的形式，利用惠司敦電橋的訊號放大及轉換，進而依薄膜的形變所產生之壓電阻變化量來達到感測壓力的目的。
利用上述製程所製作出微壓力感測元件，具有結構簡單和穩定性高的優點，並可應用於量測血壓及胎壓等各個方面。

This work focuses on the processes of fabrication and simulation for a made by the bulk-machining technologies. By intensive cross checks among MEMS-related application software and one Finite Element Analysis software, improvements can be made both in shortening the process of building model of the micro pressure sensor and in speeding up its design verification. The optimization for the pressure sensor structure is also investigated.
Regarding the analysis, the membranes 200*200μm and 400*400μm are chosen to study their changes of the resistances and the sensitivities. According to the result of simulation, the resistance changes by the square of membrane 400*400μm, compared to 200*200μm, increase about 4.79 times. As to the manufacturing process, it is designed to have ions implanted on specific regions of the n-type silicon wafer, making them become more piezoresistive. The ion implantation dosage is targeted at the level of 6*1013cm-2 and the corresponding implantation energy is 30eV. With the backside of silicon wafer being etched to form the membrane structure, the membrane sizes can be made to be 200*200μm and 400*400μm. As far as the backside etching is concerned, we tested various KOH concentration 20%、30%、40% and heating temperature 50℃、60℃、70℃、80℃、90℃. It was found that, by the observations in SEM and AFM, that a better surface roughness can be expected with KOH 30% and heating temperature 80℃. Afterwards 15, 25 and 50 μm for the membrane thickness are selected to evaluate the sensitivity. Metal connections on the micro pressure sensor are deposited by E-beam and Wheatstone bridge is utilized to show the output voltage which is effected by the changes of the four piezoresistances.
Through bulk micromachining processes mentioned above, a stable and structurally simple micro pressure sensor can be realized. The sensor may be applied either in blood pressure measuring or tire pressure detection.

摘 要 i
ABSTRACT…. ii
致 謝 iii
目 次 iv
表 目 錄 vii
圖 目 錄 viii
第一章 緒論 1
1.1 前言 1
1.2 文獻回顧 3
1.3 論文架構 5
第二章 主要製程技術簡介 6
2.1 微機電製程技術 6
2.2 半導體製程 7
2.2.1 薄膜沈積 7
2.2.2 光刻微影 11
2.2.3 蝕刻 13
2.2.4 離子佈植 15
2.3 微細加工製程 17
2.3.1 體型微細加工 18
2.3.2 面型微細加工 19
2.4 CMOS製程 22
2.5 LIGA製程 23
第三章 微壓力感測器之設計與模擬 25
3.1 壓力感測器之分類 25
3.2 壓阻式壓力感測器之基本理論 25
3.2.1 壓阻效應 26
3.2.2 工作原理 29
3.3 壓力感測器之設計 30
3.3.1 薄膜 30
3.3.2 壓阻 33
3.4 軟體模擬 34
3.4.1 CoventorWare 簡介 35
3.4.2 IntelliSuite簡介 36
3.4.3 ANSYS簡介 37
3.5 模擬流程與結果 38
第四章 壓力感測器之製作 52
4.1設計流程 52
4.2薄膜結構製作流程 57
4.3背向KOH蝕刻測試 58
4.4 凸角補償 64
4.5 AFM 量測 65
4.6 體型微加工之壓力感測器 71
4.6.1 製作流程 71
4.6.1.1 晶片清洗 73
4.6.1.2 二氧化矽沈積 73
4.6.1.3 光刻微影製程 74
4.6.1.4 BOE蝕刻 77
4.6.1.5 離子佈植製程 78
4.6.1.6 退火製程 78
4.6.1.7 背向BOE蝕刻 79
4.6.1.8 KOH蝕刻 80
4.6.1.9 E-beam沈積導線層 80
4.6.1.10 打線 82
第五章 結果與討論 84
5.1 量測與結果 84
第六章 總結與未來建議 85
參考文獻……. 87
作者簡介…….. 89

[1] C. S. Smith, “Piezoresistance Effect in Germanium and Silicon” Physics Review, 94, p.42, 1954
[2] C.　Herring “Transport Properties of a many —valley Semiconductor” Bell System Technology Journal, 34, p.237, 1955
[3] Pfann, W. G. and Thurston, R. N., "Semiconducting Stress Transducers Utilizing the Transverse and Shear Piezoresistance Effects," Journal of Applied Physics, Vol. 32, No. 10, pp.2008-2019, 1961
[4] Tufte, O. N., Chapman, P. W. and Long, D., "Silicon Diffused-Element Piezoresistive Diaphragms," Journal of Applied Physics, Vol. 33, No. 11, pp. 3322-3327, 1962
[5] O. N. Tufte, E. L. Stelzer, “Piezoresistive Properties of Silicon Diffused Layers”, Journal of Applied Physics, Vol.34, No.2, p.313 , 1963
[6] K. E. Peterson, “Silicon as A Mechanical Material,” Proceeding of the IEEE, 70.5, p. 420, 1982.
[7] P. J. French, A. G. R. Evans, “polycrystalline silicon strain sensors ”, Sensors and Actuators, A8, p.219-225, 1985
[8] H. Guckel, and D. Burns, Planar Processed Polysilicon Sealed Cavities for Pressure Transducers Array, pp. 223-225, IEDM, 1984.
[9] Guckel, H. and Burns, D. W., "Planar Processed Polysilicon Sealed Cavities for Pressure Transducer Arrays," IEDM 84, pp.223-225, 1984
[10] Samuel K. Clark and Kensall D. Wise, “Pressure Sensitivity in Anisotropically Etched Thin-Diaphragm Pressure Sensors”, IEEE Transactions on Electron Devices,Vol.ED-26, No.12, p.1887, 1979
[11] G. S. Chung, S. Kawahito, M. Ishida, and T. Nakamura, “Novel Pressure Sensors with Multilayer SOI Structure ,” Electronics Leters, 26, pp. 775-777, 1990.
[12] S. Susumu, and K. Shimaoka, “Surface Micromachined Micro-Diaphragm　 Pressure Sensors,” Solid—State Sensors and Actuators, pp. 188-191, 1991.
[13] E. Kalvesten, “The First Surface Micromachined Pressure Sensor for Cardiovascular Pressure Measurements,” IEEE, MEMS-98, pp. 574-579, 1998.
[14] S. M. Sze, Semiconductor Devices Physics And Technology, 3rd , Wiley, 1997.
[15] David A. Koester, Ramaswamy Mahadevan, Busbee Hardy and Karen W. Markus, "Design Handbook Revision 7.0", Cronos Integrated Microsystems, p.1
[16] 黃瑞星, 黃義佑, 陳建亨, “微機電共用晶片設計與製作規範”, 國科會中區微系統中心, p.19, Jan. 2002
[17] Sensors and Actuators
[18] http://www.coventor.com/
[19] http://www.intellisuite.net/public/index.asp/
[20] http://www.cadmen.com/
[21] Transene Co. Inc., "Materal safety data sheet for aluminum etchant type A", Transene Co. Inc., Rowley, MA, 1987.
[22] S.M. Sze, Semiconductor Devices-Physics and Technology, John Wiley & Sons, p410, 1985.
[23] S. M. Sze, Semiconductor Devices-Physics and Technology, Ch 10, John Wiley and Sons, Inc., New York, 1985.