Growth of Semi-Insulating GaN Using N2 as Nucleation Layer Carrier Gas Combining with an Optimized Annealing Time

Semi-insulating （SI） GaN is grown using N2 as the nucleation layer （NL） carrier gas combined with an optimized annealing time by metalorganic chemical vapour deposition. Influence of using 1-12 and N2 as the NL carrier gas is investigated in our experiment. It is found that the sheet resistance of unintentionally doped GaN can be increased from 10^4 Ω/sq to 10^10 Ω/sq by changing the NL carrier gas from 1-12 to N2 while keeping the other growth parameters to be constant, however crystal quality and roughness of the tilm are degraded unambiguously. This situation can be improved by optimizing the NL annealing time. The high resistance of GaN grown on NL using N2 as the carrier gas is due to higher density of threading dislocations caused by the higher density of nucleation islands and small statistic diameter grain compared to the one using 1-12 as carrier gas. Annealing the NL for an optimized annealing time can decrease the density of threading dislocation and improve the tilm roughness and interface of AlGaN/GaN without degrading the sheet resistance of as-grown GaN signiticantly. High-quality SI GaN is grown after optimizing the annealing time, and AlGaN/GaN high electron mobility transistors are also prepared.

绝缘半(SI ) 轧了当成核层(NL ) 搬运人气体由金属与一优化退火的时间结合了，用 N-2 被种器官的化学蒸汽免职。把 H-2 和 N-2 用作 NL 搬运人气体的影响在我们的实验被调查。这被发现表抵抗无意中做了轧能从 10 被增加( 4 )由从 H-2 把 NL 搬运人气体改变到 N-2 的终止/平方 to10 ( 10 )终止/平方当保留另外的生长参数不变时，然而，这部电影的水晶质量和粗糙明白地被降级。这种状况能被优化退火的 NL 改进时间。高抵抗轧在用搬运人气体由于穿成核岛和小统计直径谷物的更高的密度作为搬运人气体用 H-2 与那相比引起的脱臼的更高的密度的 N-2 的 NL 上成年。退火在一优化退火的时间的 NL 能减少穿脱臼的密度并且没有降级，改进电影粗糙和接口 ofAlGaN/GaN 表抵抗成长得当显著地轧了，在优化退火的时间以后种的高质量的 SI GaNis，和高选举活动性晶体管也是的 AlGaN/GaN 准备了。