Evaluation of Crystallinity in 4H–SiC{0001} Epilayers Thermally Etched by Chlorine and Oxygen System
Evaluation of Crystallinity in 4H–SiC{0001} Epilayers Thermally Etched by Chlorine and Oxygen System
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DOI：
10.1143/jjap.45.l690
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发表时间：
2006-07
影响因子：
1.5
通讯作者：
T. Hatayama;H. Yano;Y. Uraoka;T. Fuyuki
中科院分区：
文献类型：
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作者：
T. Hatayama;H. Yano;Y. Uraoka;T. Fuyuki
首次采用氯氧混合气体热蚀刻法分析了4H-SiC{0001}涂层的晶体缺陷。（0001）Si表面的蚀刻速率比（000\bar）C表面的蚀刻速率慢1 / 10以上。在（0001）Si和（0001）C表面分别观察到蚀刻坑和椭圆形丘。蚀刻坑的形状与熔融氢氧化钾法蚀刻的形状相似。平面映射电子束感应电流法证实（0001）Si表面的蚀刻坑为少数载流子陷阱。另一方面，蚀刻（0001）C表面的椭圆形丘不是少数载流子陷阱。在此基础上，讨论了腐蚀机理。
A thermal etching with a mixed gas of chlorine and oxygen was applied to analyze the crystal defects in 4H–SiC{0001} epilayers for the first time. The etching rate of the (0001)Si face was more one-tenth slower than that of the (000\bar)C face. Etch pits and oval hillocks were observed on the (0001)Si and (0001)C faces, respectively. The shapes of the etch pits were similar to those in the case of etching by a molten potassium-hydroxide method. The etch pits on the (0001)Si face were minority carrier traps as confirmed by a planar mapping electron-beam-induced current method. On the other hand, oval hillocks on the etched (0001)C face were not minority carrier traps. On the basis of these results, etching mechanisms are discussed.