單晶碳化矽晶圓(Silicon Carbide, SiC)在材料特性以及機械性質上相較於其他半導體材料，具有更明顯的優勢，如具有高崩潰電壓及低的阻抗，在高功耗應用端以及半導體市場中越來越受矚目，但也因高硬度及耐化學等特性造成單晶碳化矽基板在加工上的困難，也極度耗時和昂貴。本研究是添加過錳酸鉀(KMnO4)於冷卻液當中輔助複線式鑽石線鋸切割製程，藉由過錳酸鉀使4H單晶碳化矽材料表面產生一層較軟之反應層，利用維克式硬度、X光電子能譜儀等驗證反應層型態以及硬度值，以及利用比切削能的理論對參數進行推估。經由實驗後選定0.01M濃度過錳酸鉀用於本研究。在相同的參數條件下，透過過錳酸鉀的輔助使得切片品質在總厚度變異量、彎曲度、翹曲度分別優於未加入之切片9%、18%以及21%，在粗糙度方面也優於未加入之切片30%，且利用離子束顯微鏡拍攝切片次表層破壞，在過錳酸鉀的輔助下，也成功減少了52%的次表層破壞深度，並且可以提升9%的材料移除率，結果證明，加入過錳酸鉀後輔助鑽石線切割製程，有助於提升單晶碳化矽的切片品質，本研究也針對搖擺角度的變化去探討切片表面品質，搖擺角度5度時因接觸長度的下降，有效提升切片之總厚度變異量、翹曲率、，而搖擺角度1度則因為線材與材料接觸產生的弓角導致無法有效發揮搖擺模式的效益，造成切削力不足，連帶影響切片品質。本研究結果未來可應用於4H單晶碳化矽晶圓量產製程配方。
關鍵字: 鑽石線鋸加工、4H單晶碳化矽晶圓、過錳酸鉀、搖擺模式

Monocrystalline Silicon Carbide (SiC) wafer has high breakdown voltage and low impedance properties, compared to other semiconductor materials. It has been a promising material for high power devices and semiconductor. However, Silicon Carbide is high hardness and chemical resistance inducing the difficulty in machining. For wire sawing cutting, it takes a long time and expends a lot of diamond wire, low MRR, big sub-surface damage. This study aims to improve SiC wafer surface topography in multi-wire diamond wire sawing (MWDWS) process by adding KMnO4 into the coolant. After immersing with KMnO4, wafer surface becomes softer due to covered by an oxide layer on 4H-SiC. Experimental result shows that adding 0.01M KMnO4 solution to coolant during wire sawing can improve 2 inches as-cut SiC wafer quality on TTV 9%, Bow 18%, and Warp 21%. Moreover, MRR increases about 9%, surface roughness reduces about 30%, and sub-surface damage reduces 52%. Experiment of 4 inches as-cut SiC wafer has been taken to compare the effect of rocking angle on wafer surface topography. Result shows that using rocking angle of 5 degrees can obtain better wafer quality of TTV, Bow, and Warp. Using rocking angle of 5 degree can be improved on MRR and surface roughness. Results of this study can be further applied on high volume fabrication of 4H SiC wafers.

Keyword: Multi-Wire Diamond Wire Sawing, 4H-SiC, KMnO4, Rocking Mode.

[1] 王世忠，"SiC單晶性質、生長及應用"，無機材料學報，第14卷，第四期，1999。
[2] 顏誠廷，"碳化矽功率半導體元件"，<電子資訊>功率電子專刊，第20卷，第一期，2014
[3] D. Ravindra and J. Patten, "Determining the ductile to brittle transition (DBT) of a single-crystal 4H-SiC wafer by performing nanometric cutting", Precision Grinding and Abrasive Technology at SME International Grinding Conference, 2007.
[4] 梁峻碩，"線鋸切割太陽能基板之研究"，國立台灣科技大學，機械工程研究所碩士論文，2008。
[5] 郭炳麟，"漿料特性分析於矽晶片線鋸切割影響研究"，國立台灣科技大學，機械工程研究所碩士論文，2009。.
[6] C. C. A. Chen and P. H. Chao, "Surface texture analysis of fixed and free abrasive machining of silicon substrates for solar cells", in Advanced Materials Research, pp. 177-180, 2010,
[7] 詹明賢，"單晶與多晶矽基板鑽石線鋸加工之切屑分析研究"，國立台灣科技大學，機械工程研究所碩士論文，2014。
[8] H. Maeda, R. Takanabe, A. Takeda, S. Matsuda, and T. Kato, "High-speed slicing of SiC ingot by high-speed multi-wire saw", in 15th International Conference on Silicon Carbide and Related Materials, ICSCRM 2013, September 29, 2013 - October 4, 2013, Miyazaki, Japan, 2014, pp. 771-775.
[9] 黃浩維，"單晶碳化矽晶圓之鑽石線鋸加工模式分析研究"，國立台灣科技大學，機械工程研究所碩士論文，2015。
[10] W. Clark, A. Shih, C. Hardin, R. Lemaster, and S. McSpadden, "Fixed abrasive diamond wire machining—part I: process monitoring and wire tension force," International Journal of Machine Tools and Manufacture, vol. 43, pp. 523-532, 2003.
[11] C. Hauser, "Wire saw with means for producing a relative reciprocating motion between the workpiece to be a sawn and the wire," United States Patent, US 6886550 B2, 2005.
[12] 許仙薇，"搖擺運動於單晶氧化鋁基板鑽石線鋸切割影響之研究"，國立台灣科技大學，機械工程研究所碩士論文，2013。
[13] T.Yin, T.Doi., S.Kurokawa, O.Ohnishi, T.Yamazaki, Z.Wang, & Z.Tan, "Processing Properties of Strong Oxidizing Slurry and effect of processing atmosphere in sic-cmp". In Planarization/CMP Technology (ICPT 2012), International Conference on, pp. 1-6, 2012.
[14] A.Hideo, T.Doi, H.Takeda, , "Ultraprecision CMP for sapphire, GaN, and SiC for advanced optoelectronics materials." Current Applied Physics 12, pp.41-46, 2012.
[15] J.Zhang, S.Kurokawa, T.Hayashi, E.Asakawa,"Processing characteristics of SiC wafer by consideration of oxidation effect in different atmospheric environment". In Planarization/CMP Technology (ICPT), 2014 International Conference on , pp. 279-282. IEEE, 2014.
[16] G.Chen, Z.Ni, L.Xu, Q.Li, & Y.Zhao, "Performance of colloidal silica and ceria based slurries on CMP of Si-face 6H-SiC substrates". Applied Surface Science, 359, pp.664-668, 2015.
[17] 徐軍，“一種超硬晶體切割方法”，大陸專利CN101386192 A， 2009。
[18] 張革，“旋轉點切割大尺寸碳化矽晶體裝置”，大陸專利CN1724234 A，2009。
[19] 高玉強，“一種利用金剛石線切割大直徑碳化矽單晶的方法和設備”，大陸專利CN103722625 A，2014。
[20] B. R. Lawn, A. Evans, and D. Marshall, "Elastic/plastic indentation damage in ceramics: the median/radial crack system", Journal of the American Ceramic Society, vol. 63, pp. 574-581, 1980.
[21] C. B. Carter and M. G. Norton, "Ceramic materials: science and engineering", 2007.
[22] 陳建民，"鑽石線鋸切割碳化矽與氧化鋁陶瓷材料特性研究"，國立清華大學，動力機械工程研究所碩士論文，2003。
[23] 楊祥龍，"一種半絕緣4H-SiC晶型鑑別方法"，大陸專利CN103543397 A，2014
[24] 楊竣凱，"複合式能量化學機械拋光於單晶碳化矽基板平坦化製程之研究"，國立台灣科技大學，機械工程研究所碩士論文， 2014。
[25] 陳鼎鈞，"單晶碳化矽基板之鑽石研光與化學機械拋光平坦化製程研究"，國立台灣科技大學，機械工程研究所碩士論文， 2015。
[26] 張士宸，"氣液輔助化學機械拋光應用於單晶碳化矽基板之化平坦化製程分析研究"，國立台灣科技大學，機械工程研究所碩士論文， 2016。
[27] 張立信，"表面化學分析技術"，奈米通訊，第19卷，第四期。
[28] J.F.Moulder, "Handbook of X-ray photoelectron spectroscopy: a reference book of standard spectra for identification and interpretation of XPS data. " Eds. Jill Chastain, and Roger C. King. Eden Prairie, Minnesota: Physical Electronics Division, Perkin-Elmer Corporation, 1992.
[29] M.Capelle, J.Billoué, T.Defforge, P.Poveda, & G.Gautier, "Evaluation of mesoporous silicon substrates strain for the integration of radio frequency circuits. Thin Solid Films, 585, pp.66-71. 2015。
[30] 吳小瓊，王志江，"無機化學"，第138-153頁，西安交通大學出版社，西安，中國，2012。