Anisotropic etching mechanisms of 4H-SiC:Experimental and first-principles insightsOA北大核心CSTPCD
Molten-alkali etching has been widely used to reveal dislocations in 4H silicon carbide(4H-SiC),which has promoted the identification and statistics of dislocation density in 4H-SiC single crystals.However,the etching mechanism of 4H-SiC is limited misunderstood.In this letter,we reveal the anisotropic etching mechanism of the Si face and C face of 4H-SiC by combining molten-KOH etching,X-ray photoelectron spectroscopy(XPS)and first-principles investigations.The activation energies for the molten-KOH etching of the C face and Si face of 4H-SiC are calculated to be 25.09 and 35.75 kcal/mol,respectively.The molten-KOH etching rate of the C face is higher than the Si face.Combining XPS analysis and first-principles calculations,we find that the molten-KOH etching of 4H-SiC is proceeded by the cycling of the oxidation of 4H-SiC by the dissolved oxygen and the removal of oxides by molten KOH.The faster etching rate of the C face is caused by the fact that the oxides on the C face are unstable,and easier to be removed with molten alkali,rather than the C face being easier to be oxidized.
Guang Yang;Lingbo Xu;Can Cui;Xiaodong Pi;Deren Yang;Rong Wang;
Key Laboratory of Optical Field Manipulation of Zhejiang Province,Department of Physics,Zhejiang Sci-Tech University,Hangzhou 310018,China Institute of Advanced Semiconductors&Zhejiang Provincial Key Laboratory of Power Semiconductor Materials and Devices,HangzhoIun novation Center,Zhejiang University,Hangzhou 311200,ChinaKey Laboratory of Optical Field Manipulation of Zhejiang Province,Department of Physics,Zhejiang Sci-Tech University,Hangzhou 310018,ChinaState Key Laboratory of Silicon and Advanced Semiconductor Materials&School of Materials Science and Engineering,Zhejiang University,Hangzhou 310027,China Institute of Advanced Semiconductors&Zhejiang Provincial Key Laboratory of Power Semiconductor Materials and Devices,HangzhoIun novation Center,Zhejiang University,Hangzhou 311200,China
物理学
principlesalkalietching
《Journal of Semiconductors》 2024 (001)
P.42-47 / 6
This work is supported by the Natural Science Foundation of China(Grant Nos.62274143&62204216);Joint Funds of the Zhejiang Provincial Natural Science Foundation of China(Grant Nos.LHZSD24E020001);the“Pioneer”and“Leading Goose”R&D Program of Zhejiang(Grant Nos.2022C0102&2023C01010);Partial support was provided by the Leading Innovative and Entrepreneur Team Introduction Program of Hangzhou(Grant No.TD2022012);Fundamental Research Funds for the Central Universities(Grant No.226-2022-00200);the Natural Science Foundation of China for Innovative Research Groups(Grant No.61721005);the Open Fund of Zhejiang Provincial Key Laboratory of Wide Bandgap Semiconductors,Hangzhou Global Scientific and Technological Innovation Center,Zhejiang University.
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