臺灣博碩士論文加值系統

本文主要利用微機電製程於四吋矽晶圓上製作出表面鍍有氮化矽薄膜之單晶矽微懸臂樑結構，使用微拉力試驗機搭配探針對微矽懸樑作彎曲及高頻、低頻疲勞測試，探討表面鍍膜的厚度對懸臂樑機械性質之影響。在彎曲測試中，表面膜厚為0.2μm之微懸臂樑，其平均彎曲強度為1.23GPa，最大破壞應變為10.0×10-3；而表面膜厚為0.4μm之微懸臂樑，其平均破壞強度為1.04GPa，最大破壞應變為7.8×10-3。利用有限元素法，將樑底切長度的差異修正後，表面膜厚為0.4μm的樑其破壞強度大於膜厚為0.2μm的樑有3.25%，是因為表面鍍膜越厚，在樑受力的時候，其純矽表面所受到的應力越小。
在高頻(100Hz)、低頻(40Hz)疲勞測試中，皆取破壞應變的50%~85%作為二倍應變振幅對微懸臂樑進行測試。在高頻試驗中，成功的利用基層型壓電材料作為振動源，使得疲勞試驗所花費的時間得以縮短。所得的疲勞壽命在1.0×106到2.0×107之間，並以膜厚為0.2μm的微懸臂樑其疲勞壽命較高，主要是因為較薄的薄膜在沈積中產生的缺陷較少，且緻密性高，雖然對於彎曲強度的補強效果較低，但是在受循環應變下，其膜的附著性與耐久性皆優於膜厚為0.4μm的微懸臂樑試片。
另外利用SEM觀察破斷面型態，彎曲試驗的破斷面皆沿著{111}面結晶面產生，且大致光滑平整；疲勞破斷面則較彎曲破斷面更為粗糙，並有裂縫從樑內部生成，造成向內掏空侵蝕單晶矽的情況。

In this thesis, the influence of Si3N4 coating on mechanical properties of single crystal silicon micro-cantilever beam fabricated on 4〞wafers by MEMS techniques is studied. A MTS micro-force testing machine (Tytron 250) with a probe is adopted for bending test, high frequency fatigue and low frequency fatigue tests.
The beam with coating 0.2μm Si3N4 has the following mechanical properties: average flexural strength 1.23GPa, failure strain 10.0×10-3. The beam with surface coating 0.4μm Si3N4 has the following properties: average flexural strength 1.04GPa, failure strain 7.8×10-3. After using finite element method software (ANSYS) to modify the influence of undercut of beam, the flexural strength of the beam with 0.4μm Si3N4 coating is 3.25% higher than that with 0.2μm coating and is the net effect of coating thickness on flexural strength.
For high frequency(100Hz) fatigue and low frequency(40Hz) fatigue tests conducted by strain amplitude(50%~85% failure strain), the fatigue lives of beams with surface coating is ranged from 1.0×106 to 2.0×107 cycles . In high frequency fatigue test, using multilayer piezoelectric actuator can effectively reduce time for fatigue test. The beam with 0.2μm Si3N4 coating has better fatigue life than the beam with 0.4μm coating. Because the thinner film has less defects than the thicker film, it can resist stress under strain cycles.
In observing the flexural fracture plane by SEM, the bending fracture plane occurs along the lattice plane {111} and the plane is approximately smooth. The fatigue fracture plane is rougher than flexural fracture plane, and has crack on the fixed end of the beam.

中文摘要………………………………………………………………….I
英文摘要………………………………………………………………..III
目錄……………………………………………………………………...V
表目錄………………………………………………………………VIII
圖目錄…………………………………………………………………. X
第一章 緒論…………………………………………………………….1
1.1 研究動機…………………………………………………………1
1.2 研究目的…………………………………………………………2
1.3 文獻回顧…………………………………………………………3
1.4 研究方法…………………………………………………………6
第二章 理論分析………………………………………………………13
2.1 樑結構變形理論………………………………………………..13
2.2 晶體缺陷………………………………………………………..15
2.3 循環應變理論…………………………………………………..18
2.4 疲勞試驗理論…………………………………………………..21
第三章 試片製作………………………………………………………25
3.1 試片尺寸………………………………………………………25
3.2 製程規劃……………………………………………………….26
3.3 薄膜沈積……………………………………………………….30
3.4 黃光製程………………………………………………………..32
3.5 蝕刻製程………………………………………………………..34
3.6 實驗設備………………………………………………………..38
第四章 試驗規劃………………………………………………………44
4.1 夾具設計……………………………………………………….44
4.2 試驗設計與流程………………………………………………..44
4.2.1 彎曲試驗…………………………………………………..45
4.2.2 低頻疲勞試驗……………………………………………..46
4.2.3高頻疲勞試驗……………………………………………..48
第五章 結果與討論……………………………………………………58
5.1 微懸臂樑與表層薄膜…………………………………………..58
5.1.1 外型尺寸…………………………………………………..58
5.1.2 表面粗糙度……………………………………………….60
5.2 微懸臂樑彎曲試驗……………………………………………..61
5.2.1應力應變關係與楊氏係數………………………………..61
5.2.2彎曲強度與表面膜厚關係………………………………..63
5.2.3彎曲強度與尺寸關係……………………………………..65
5.2.4正反面負載測試………………………………………..65
5.2.5 破壞面顯微觀察…………………………………………..66
5.3 疲勞測試………………………………………………………..68
5.3.1低頻疲勞試驗……………………………………………..69
5.3.2高頻疲勞試驗……………………………………………..71
5.3.3 破壞面顯微觀察…………………………………………..73
第六章 結論與未來研究發展………………………………………..112
6.1 結論……………………………………………………………112
6.2 未來研究發展…………………………………………………115
參考文獻………………………………………………………………118

1.劉邦平，"矽微懸臂樑之彎曲及疲勞測試"，逢甲大學機械所碩士論文，民國九十三年。
2.周琦斌，"矽微懸臂樑表面鍍膜之機械性質"，逢甲大學機械所碩士論文，民國九十四年。
3.徐泰然，"微機電系統與微系統設計與製造"，美商麥格羅•希爾國際股份有限公司 台灣分公司，台北，2003。
4.國科會精儀中心，"微機電系統技術與應用"，全華，新竹，2003。
5.Kirt R. Williams, and Richard S. Muller, (1996), "Etch Rates for Micromachining Processing", J. of MEMS, Vol. 5, No. 4, pp. 256-296.
6.Kirt R. Williams, Kishan Gupta, and Matthew Wasilik, (2003), "Etch Rates for Micromachining Processing – Part II", J. of MEMS, Vol. 12, No. 6, pp. 761-777.
7.O. M. JADAAN, (2003), "Probabilistic Weibull behavior and mechanical properties of MEMS brittle materials", Journal of Materials Science 38, pp. 4087-4113.
8.R.L. Edwards, G. Coles and W.N. Sharpe, Jr, (2004), "Comparison of Tensile and Bulge Tests for Thin-Film Silicon Nitride", 2004 Society for Experimental Mechanics, Vol. 44, No. 1, pp.49-54.
9.Sharpe,W. N., Jr., Yuan, B., Vaidyanathan, R., and Edwards, R. L., (1996), "New Test Structures and Techniques for Measurement of Mechanical Properties of MEMS Materials", Proceedings of the SPIE Symposium on Microlithography and Metrology in Micromachining II, Austin, TX, 78-91.
10.T. Namazu, Y. Isono, T. Tanaka, (2000), "Nano-Scale Bending Test of Si Beam for MEMS", IEEE, pp. 205-210.
11.Ching-Liang Dai , Yuan-Ming Chang, (2006), "A resonant method for determining mechanical properties of Si3N4 and SiO2 thin films", Materials Letters 61, pp. 3089-3092.
12.C. J. Wilson, A. Ormeggi, M. Narbutovskih, (1995), "Fracture testing of silicon microcantilever beams", J. Appl. Phys. 79(5), pp. 2386-2393.
13.C. J. Wilson, and A. P. Beck,(1996), "Facture Testing of Bulk Silicon Microcantilever Beams Subjected to a Side Load", J. of MEMS, Vol. 5, No. 3, pp.142-150.
14.S. Sundararajan, B. Bhushan, T. Namazu, Y. Isono, (2002), "Mechanical property measurements of nanoscale structures using an atomic force microscope", Ultramicroscopy, 91, pp. 111-118.
15.Wen-Hsien Chuang , Rainer K. Fettig, Reza Ghodssi, (2005), "An electrostatic actuator for fatigue testing of low-stress LPCVD silicon nitride thin films", Sensors and Actuators A, Vol.121, pp. 557-565.
16.R. Schwaiger, O. Kraft, (2003), "Size effects in the fatigue behavior of thin Ag films", Acta Materialia 51, pp. 195-206.
17.Meng Nie, Qing-An Huang, and Weihua Li, (2006), "Measurement of residual stress in multilayered thin films by a full-field optical method", Sensors and Actuators A: Physical, Vol.126, pp. 93-97.
18.林震、劉興華、蘇金佳譯，"材料力學"，東華書局，台北，2001。
19.徐灝，"疲勞強度"，高等教育出版社，北京，1990。
20.Joseph E. Shigley, Charies R. Mischke, Richard G. Budynas, “Essentials of Mechanical Engineering Design”, first edition, McGraw-Hill, 2004.
21.W. A. Brantly, (1973), "Calculated elastic constants for stress problems associated with semiconductor devices", J. Appl.Phys. Vol. 44, No.1, pp. 534-535.
22.Y. Taechung, L. LU, K. C. Jin, (2000), "Microscale material testing of single crystalline silicon: process effects on surface morphology and tensile strength", Sensors and Actuators A : Physical 83, pp. 172-178.
23.B. Bhushan, B.K. Gupta, "Handbook of Tribology : Materials, Coatings and Surface Treatments", McGraw-Hill, New York, 1991.
24.K. Sato, T. Yoshioka, T. Ando, (1998), "Tensile testing of silicon film having different crystallographic orientations carried out on a silicon chip", Sensors and Actuators A : Physical 70, pp. 148-152.
25.D. Resnik ,U. Aljancic,D. Vrtacnik,M. Mozˇek,S. Amon, 2005, "Mechanical stress in thin film microstructures on silicon substrate", Vacuum 80, pp 236-240.