電動汽車、再生能源及快速充電等高功率元件的應用矽功率元件已無法滿足市場需求，因此單晶碳化矽 (SiC) 相較於單晶矽具有高寬能隙、高崩潰電壓及高熱傳導率等特性較適合用於高功率元件，然而單晶碳化矽具有較高硬度(Mohs硬度為 9.25-9.50或2800 Kg/mm2)，硬度僅次於鑽石，所以單晶碳化矽進行磨削，研光與化學機械拋光 (Chemical Mechanical Polishing, CMP)需要使用較多的時間，同時須使用較多的耗材，會增加製造成本，因此如何縮短加工時間及降低製造成本是一重要的研究課題。本研究提出一種研磨複合盤的新穎製作方法用於4H-SiC晶圓矽面的研磨加工，藉由複合盤及氯化銀/銀原子簇的光觸媒(Photocatalytic)催化研磨液中雙氧水的分解反應，增加羥基自由基的形成，用以增加4H-SiC晶圓矽面快速形成非晶質的二氧化矽，進而增加4H-SiC晶圓矽面的研磨效率。添加氯化銀光觸媒能有效的產生氫氧自由基能與4H-SiC矽面懸空鍵鍵結反應，透過拉曼檢測發現有效提升氧化層生成。單純添加6.0 wt%過氧化氫所得到之材料移除率會上升約29.5%；研光液添6.0 wt%的過氧化氫與10.0wt%的氯化銀光觸媒並以紫外光燈照射其中，材料移除率為會上升約85.6%，最後使用化學機械拋光製程(Chemical Mechanical Polishing, CMP)讓4H-SiC矽面的表面粗糙度達到Sa為0.1nm，同時減少整個加工時間達33.3%。

Silicon wafers are not fully substainable for the application of high-power components such as electric vehicles, recycle energy and fast charging. Therefore, single crystal silicon carbide (SiC) has a high energy gap, high breakdown voltage and high thermal conductivity compared with single crystal silicon, and it has been applied to high power components. However, single crystal silicon carbide has a high hardness (Mohs hardness of 9.25-9.50 or 2800Kg/ mm2), lower than diamond, so the single crystal SiC lapping and chemical mechanical polishing (CMP) require long processing time, more consumables, and more manufacturing cost. It is important to shorten the processing time and reduce the manufacturing cost. This study has developed a novel manufacturing method of composited platen for lapping of Si-face of 4H-SiC wafers. During the lapping process, the decomposition reaction of hydrogen peroxide in the slurry is catalyzed by the photocatalytic catalyzed for silver chloride/silver clustering of the composited platen. The increasing formation of hydroxyl radicals is used to improve the formation of the amorphous silicon oxide rapidly on the surface of the Si-face of 4H-SiC wafer, thereby increasing the lapping and polishing efficiency of the Si-face of 4H-SiC wafer. The addition of silver chloride photocatalyst can effectively produce hydroxyl radicals and react with the dangling bonds of Si-face of 4H-SiC.
Through Raman analysis, it is found to improve the formation of oxide layer effectively. The material removal rate (MRR) by adding 6.0 wt% hydrogen peroxide in the lapping solution can increased as 29.5%. Adding 6.0 wt% hydrogen peroxide and 10.0 wt% silver chloride photocatalyst and irradiated with ultraviolet light in the lapping solution, the MRR increases to 85.6%. Finally, the CMP process is used to achieve a surface roughness 0.1 nm of Si-face of 4H-SiC of while reducing the overall processing time by up to 33.3%.

[1] " The Next Generation of Power Conversion Systems Enabled by SiC Power Devices," ROHM Semiconductor, 2014.
[2] " Innovative Power Devices for a Sustainable Future, " MITSUBISHI Electric, 2019.
[3] Philip G. Neudeck, " SiC TECHNOLOGY," Book Chapter in VLSI Technology, pages 6-1 to 6-32, Jan., 1998. ( published 19 Mar 2003 )
[4] Mun Teng Soo, "Advances of SiC-based MOS capacitor hydrogen sensors for harsh environment applications, " Sensors and Actuators B: Chemical, Volume 151, Issue 1, Pages 39-55, 2010.
[5] Yan Zhou, " Effects of ultra-smooth surface atomic step morphology on chemical mechanical polishing (CMP) performances of sapphire and SiC wafers, Tribology International, " Volume 87, Pages 145-150, 2015.
[6] Xuejiang Chen, " Stepped morphology on vicinal 3C- and 4H-SiC (0001) faces: A kinetic Monte Carlo study, " Surface Science, Volume 681, Pages 18-23, 2019.
[7] Tsuchida, " Formation of extended defects in 4H-SiC epitaxial growth and development of a fast growth technique, " Physica Status Solidi B Basic Research, 246, 7, 1553-1568, Jul., 2009.
[8] Akihisa Kubota, " Fabrication of Smooth Surface on 4H-SiC Substrate by Ultraviolet Assisted Local Polishing in Hydrogen Peroxide Solution, " Key Engineering Materials 523-524:24–28, 2012.
[9] Ming-Yi Tsai, Yue-Feng Lin, Guan-Fu Lin " Development of Combined Diamond-impregnated Lapping Plates, " Int J Adv Manuf Technol 105, 1519–1530, 2019.
[10] Vacassy, R., " Surface Engineering of SiC through Nanogrinding and CMP, " Materials Science Forum, 924, 539–542, Jun., 2018.
[11] Yang Jyun-Kai, "Research on Hybrid Energy Chemical Mechanical Polishing of Monocrystalline Silicon Carbide Substrate, " Master Thesis of National Taiwan of Science and Technology, 2014.
[12] Ding Jyun Chen, " Research on Diamond Lapping and Chemical Mechanical Polishing of Single Crystalline Silicon Carbide Substrate, " Master Thesis of National Taiwan of Science and Technology, Jul., 2015.
[13] Shih-Chen Chang, " Research on Gas Liquid Assisted Chemical Mechanical Polishing of Monocrystalline Silicon Carbide Substrate, " Master Thesis of National Taiwan of Science and Technology, Jul., 2016.
[14] Junji Murata, " Polishing-pad-free electrochemical mechanical polishing of single-crystalline SiC surfaces using polyurethane–CeO2 core–shell particles, " International Journal of Machine Tools and Manufacture, Volume 114, Pages 1-7, 2017.
[15] Yu Chen Huang, " Study on Graphene Oxide Hybrid Slurry in Chemical Mechanical Polishing of Monocrystalline Silicon Carbide Wafer, " Master Thesis of National Taiwan of Science and Technology, Jul., 2017.
[16] Tao Yin, " Polishing Characteristics of MnO2 Polishing Slurry on the Si-face of SiC Wafer, " Int. J. Precis. Eng. Manuf. 19, 1773–1780, 2018.
[17] Takeshi Tanaka, " Verification of the Effectiveness of UV-Polishing for 4H-SiC Wafer Using Photocatalyst and Cathilon, International Journal of Automation Technology, " Volume 12, Issue 2, Pages 160-169, Nov. 05, 2018.
[18] Zewei Yuan, " UV-TiO2 photocatalysis-assisted chemical mechanical polishing 4H-SiC wafer, Materials and Manufacturing Processes, " 33:11, 1214-1222, 2018.
[19] Shikha Garg, " Mechanistic Insights into Free Chlorine and Reactive Oxygen Species Production on Irradiation of Semiconducting Silver Chloride Particles, " particles, Silver Ions and Reactive Oxygen Species. Langmuir, 28, 10266−10275. 2012.
[20] N. Selvi, " Effect of ZnO SiO2 dual shells on CeO2 hybrid core–shell nanostructures and their structural, optical and magnetic properties, " RSC Adv., 4, 55745, 2014.
[21] Bi Xiangyu, " Detection and Surface Reactivity of Engineered Nanoparticles in Water, " Environmental engineering; Nanoscience ; Chemistry, Arizona State University, Jan., 2018.
[22] Hui Deng, " Electro-chemical mechanical polishing of single-crystal SiC using CeO2 slurry, Electrochemistry Communications, " Volume 52, Pages 5-8, 2015.
[23] Zhi-Gang Chen, " Synthesis of Nano-Sized Ceo2 Via Alcohol-water Method and Its Polishing Performance on GaAs Wafer, "中國有色金屬學報, Page: 138-143, 2015.