Effect of carbon doping on buffer leakage in AlGaN/GaN high electron mobility transistors
Effect of carbon doping on buffer leakage in AlGaN/GaN high electron mobility transistors
复制标题
DOI：
10.1116/1.1752907
复制
发表时间：
2004-05-01
影响因子：
1.4
通讯作者：
Speck, JS
中科院分区：
文献类型：
--
作者：
Poblenz, C;Waltereit, P;Speck, JS
研究了射频等离子体辅助分子束外延生长的AlGaN/GaN高电子迁移率晶体管中通过CBr4掺杂降低缓冲层漏的方法。对于结构的前400 nm处的碳掺杂，随着总碳浓度的增加，缓冲液泄漏显著减少。发现了一种碳掺杂方案，其中掺杂水平从6×10(17)cm(-3)逐渐减小到2×10(17)cm(-3)，从而产生足够低的漏源漏电流。探讨了GaN：C层厚度的影响，以及后续非故意掺杂GaN层厚度的影响。对于漏电流减少的结构，射频I-V和功率测量表明，在二维电子气与GaN：C层相距较远的结构中，其性能更好。根据结果，讨论了导致这些结构泄漏的非故意自由载流子的可能来源和位置。(C)2004年美国真空协会。
Carbon doping via CBr4 in AlGaN/GaN high electron mobility transistors grown by rf-plasma-assisted molecular beam epitaxy on 4H-SiC (0001) was investigated as a means to reduce buffer leakage. For carbon doping in the first 400 nm of the structure, a significant decrease in buffer leakage was observed with increasing overall carbon concentration. A carbon doping scheme in which the level of doping is tapered from 6 x 10(17) cm(-3) down to 2 x 10(17) cm(-3) was found to result in sufficiently low drain-source leakage currents. The effect of thickness of the GaN:C layer was explored as well as the effect of thickness of the subsequent unintentionally doped GaN layer. For structures with reduced leakage, rf I-V and power measurements revealed better performance in structures in which the two-dimensional electron gas was spaced at a large distance from the GaN:C layer. Possible sources and locations of unintentional free carriers contributing to leakage in these structures are discussed in light of the results. (C) 2004 American Vacuum Society.