Impact of GaAs buffer thickness on electronic quality of GaAs grown on graded Ge/GeSi/Si substrates
Impact of GaAs buffer thickness on electronic quality of GaAs grown on graded Ge/GeSi/Si substrates
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DOI：
10.1063/1.126200
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发表时间：
2000-03
影响因子：
4
通讯作者：
J. Carlin;S. Ringel;E. Fitzgerald;M. Bulsara;B. Keyes
中科院分区：
文献类型：
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作者：
J. Carlin;S. Ringel;E. Fitzgerald;M. Bulsara;B. Keyes
在分子束外延过程中，采用GaAs/Ge界面成核的单层尺度控制方法，研究了在Si衬底上生长的GaAs的少子寿命和界面复合速度随GaAs缓冲层厚度的变化。GaAs层没有反相畴无序，通过蚀刻坑密度测量的穿透位错密度为5×105-2×106 cm−2。分析表明，当GaAs缓冲层厚度小于0.1 μm时，少数载流子寿命和界面复合速度均未下降。实际上，在0.1 μ mGaAs缓冲层的Si衬底上，GaAs的少数载流子寿命已超过10 ns。二次离子质谱表明，交叉扩散的Ga，As和Ge在GaAs/Ge界面上形成的梯度GeSi缓冲层低于检测限的界面区域，表明极性控制的GaAs/Ge界面上形成的GeSi/Si衬底上可以实现。
Minority carrier lifetimes and interface recombination velocities for GaAs grown on a Si wafer using compositionally graded GeSi buffers have been investigated as a function of GaAs buffer thickness using monolayer-scale control of the GaAs/Ge interface nucleation during molecular beam epitaxy. The GaAs layers are free of antiphase domain disorder, with threading dislocation densities measured by etch pit density of 5×105–2×106 cm−2. Analysis indicates no degradation in either minority carrier lifetime or interface recombination velocity down to a GaAs buffer thickness of 0.1 μm. In fact, record high minority carrier lifetimes exceeding 10 ns have been obtained for GaAs on Si with a 0.1 μm GaAs buffer. Secondary ion mass spectroscopy reveals that cross diffusion of Ga, As, and Ge at the GaAs/Ge interface formed on the graded GeSi buffers are below detection limits in the interface region, indicating that polarity control of the GaAs/Ge interface formed on GeSi/Si substrates can be achieved.