Improvement of Breakdown Characteristics of a GaN HEMT with AlGaN Buffer Layer
Improvement of Breakdown Characteristics of a GaN HEMT with AlGaN Buffer Layer
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DOI：
10.1007/s11664-011-1864-x
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发表时间：
2012-03
影响因子：
2.1
通讯作者：
Y. Chen;Y. Jiang;P. Xu;Z. G. Ma;X. Wang;T. He;M. Peng;W. Luo;X. Y. Liu;L. Wang;H. Jia;H. Chen
中科院分区：
文献类型：
--
作者：
Y. Chen;Y. Jiang;P. Xu;Z. G. Ma;X. Wang;T. He;M. Peng;W. Luo;X. Y. Liu;L. Wang;H. Jia;H. Chen
采用金属有机化学气相沉积的方法，在6H-SiC衬底上生长了具有高阻两层缓冲层（AlGaN/GaN）的高电子迁移率晶体管（hemt）。并与采用氮化镓作为高阻缓冲层的hemt进行了比较。x射线衍射和原子力显微镜结果表明，AlGaN缓冲层并没有使HEMT异质结构的晶体质量恶化。两种不同结构的hemt的直流特性相似，但AlGaN缓冲层提高了脱态击穿电压，提高了二维电子气的迁移率。系统地讨论了海藻酸盐缓冲层作用的原因。
High-electron-mobility transistors (HEMTs) with a highly resistive two-layer buffer layer (AlGaN/GaN) were grown on 6H-SiC substrates by metalorganic chemical vapor deposition. The characteristics were compared with those of conventional HEMTs utilizing GaN as the high-resistivity buffer. The results of x-ray diffraction and atomic force microscopy indicate that the crystal quality of the HEMT heterostructure is not deteriorated by the AlGaN buffer layer. The direct-current (DC) characteristics of the HEMTs with the two different structures are similar, while the off-state breakdown voltage is enhanced and the mobility of the two-dimensional electron gas is improved by the AlGaN buffer layer. The reasons for the effects of the AlGaN buffer layer are discussed systematically.