Fenton reaction chemical mechanical polishing liquid composition optimization of polishing GaN wafer
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摘要: 针对芬顿反应CMP抛光GaN晶片的抛光液,开展以表面质量为评价指标的参数优化试验,找出抛光液组分的最优配比。结果表明:当H2O2质量分数为7.5%时,GaN晶片加工表面效果最优,表面粗糙度达到3.2 nm;催化剂能有效调节芬顿反应的速率,对比液体催化剂FeSO4溶液和固体催化剂Fe3O4粉末,固体催化剂Fe3O4粉末能在溶液中持续电离Fe2+,使芬顿反应能在整个加工过程中持续作用。当Fe3O4粉末粒径为20 nm时,抛光效果最佳,表面粗糙度达到3.0 nm;对比氧化铝、氧化铈、硅溶胶磨料,硅溶胶磨料抛光的表面效果最佳,晶片表面粗糙度达到3.3 nm;当硅溶胶磨料质量分数为20.0%,磨料粒径为60 nm时,抛光后晶片表面粗糙度达到1.5 nm。抛光液组分优化后,采用最优的抛光液组分参数抛光GaN晶片,其能获得表面粗糙度为0.9 nm的光滑表面。Abstract: Aiming at the polishing liquid used for polishing GaN wafers by Fenton reaction CMP, a parameter optimization experiment was carried out with the surface quality as the evaluation index, and the optimal ratio of the polishing liquid components was found out. The results show that when the mass fraction of H2O2 is 7.5%, the surface of GaN wafer processing is the best, and the surface roughness reaches 3.2 nm; the catalyst can effectively adjust the rate of the Fenton reaction. Compared with the liquid catalyst FeSO4 solution and the solid catalyst Fe3O4 powder, the solid catalyst Fe3O4 powder can continuously ionize Fe2+ in the solution, so that the Fenton reaction can continue to work throughout the process. When the particle size of Fe3O4 powder is 20 nm, the polishing surface is the best, and the surface roughness reaches 3.0 nm; compared with alumina, cerium oxide, and silica sol abrasives, the best surface polishing effect can be achieved while using the silica sol abrasives, and the surface roughness reaches 3.3 nm; when the mass fraction of silica sol abrasive is 20.0% and the abrasive particle size is 60 nm for polishing, the surface roughness reaches 1.5 nm. After optimizing the composition of the polishing liquid, the GaN wafer was polished with the optimal composition parameters of the polishing liquid, and a smooth surface with a surface roughness of 0.9 nm could be obtained.
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Key words:
- GaN wafer /
- Fenton reaction /
- CMP polishing /
- catalyst
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[1] 熊朋, 王铮, 陈威, 等. 氮化镓晶片的CMP技术现状与趋势 [J]. 电子工业专用设备, 2016, 45(1): 10-14.XIONG Peng, WANG Zheng, CHEN Wei, et al. Current situation and trend of CMP technology for GaN wafers [J]. Equipment for Electronic Products Manufacturing, 2016, 45(1): 10-14. [2] 邓家云, 潘继生, 张棋翔, 等. 单晶SiC基片的化学机械抛光技术研究进展 [J]. 金刚石与磨料磨具工程,2020,40(1):79-91. doi: 10.13394/j.cnki.jgszz.2020.1.0013DENG Jiayun, PAN Jisheng, ZHANG Qixiang, et al. Research progress in chemical mechanical polishing of single crystal SiC substrates [J]. Diamond & Abrasives Engineering,2020,40(1):79-91. doi: 10.13394/j.cnki.jgszz.2020.1.0013 [3] 黄伟英, 刘菲, 鲁安怀, 等. 过氧化氢与过硫酸钠去除有机污染物的进展 [J]. 环境科学与技术,2013,36(9):88-95. doi: 10.3969/j.issn.1003-6504.2013.09.018HUANG Weiying, LIU Fei, LU Anhuai, et al. Progress in the removal of organic pollutants by hydrogen peroxide and sodium persulfate [J]. Environmental Science and Technology,2013,36(9):88-95. doi: 10.3969/j.issn.1003-6504.2013.09.018 [4] 张洋, 赵静. 芬顿反应控制条件研究进展 [J]. 化学工程与装备,2019(12):206-207. doi: 10.19566/j.cnki.cn35-1285/tq.2019.12.096ZHANG Yang, ZHAO Jing. Research progress of Fenton reaction control conditions [J]. Chemical Engineering and Equipment,2019(12):206-207. doi: 10.19566/j.cnki.cn35-1285/tq.2019.12.096 [5] KUBOTA A, YAGI K, MURATA J, et al. A study on a surface preparation method for single-crystal SiC using an Fe catalyst [J]. Journal of Electronic Materials,2009,38(1):159-163. doi: 10.1007/s11664-008-0583-4 [6] MURATA J, NISHIGUCHI Y, IWASAKI T. Liquid electrolyte-free electrochemical oxidation of GaN surface using a solid polymer electrolyte toward electrochemical mechanical polishing [J]. Electrochemistry Communications,2018,97:110-113. doi: 10.1016/j.elecom.2018.11.006 [7] OU L W, WANG Y H, HU H Q, et al. Photochemically combined mechanical polishing of N-type gallium nitride wafer in high efficiency [J]. Precision Engineering,2019,55:14-21. doi: 10.1016/j.precisioneng.2018.08.002 [8] 阎秋生, 徐少平, 路家斌, 等. 单晶SiC化学机械抛光液化学反应参数研究 [J]. 机械设计与制造,2017(9):98-100, 104. doi: 10.3969/j.issn.1001-3997.2017.09.026YAN Qiusheng, XU Shaoping, LU Jiabin, et al. Study on chemical reaction parameters of single crystal SiC chemical mechanical polishing solution [J]. Mechanical Design and Manufacturing,2017(9):98-100, 104. doi: 10.3969/j.issn.1001-3997.2017.09.026 [9] 徐少平, 路家斌, 阎秋生, 等. 单晶SiC化学机械抛光液的固相催化剂研究 [J]. 机械工程学报,2017,53(21):167-173. doi: 10.3901/JME.2017.21.167XU Shaoping, LU Jiabin, YAN Qiusheng et al. Research on solid phase catalyst of single crystal SiC chemical mechanical polishing liquid [J]. Journal of Mechanical Engineering,2017,53(21):167-173. doi: 10.3901/JME.2017.21.167 [10] 邓家云, 潘继生, 阎秋生. 单晶SiC化学机械抛光基础研究——电芬顿反应条件优化及6H-SiC氧化效果分析 [J]. 表面技术, 2020, 49(4): 64-73.DENG Jiayun, PAN Jjisheng, YAN Qiusheng. Basic research on chemical mechanical polishing of single crystal SiC— Optimization of Electro-Fenton reaction conditions and analysis of 6H-SiC oxidation effect [J]. Surface Technology, 2020, 49(4): 64-73.