Silicon–germanium interdiffusion in strained Ge/SiGe multiple quantum well structures
Silicon–germanium interdiffusion in strained Ge/SiGe multiple quantum well structures
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DOI：
10.1088/0022-3727/43/50/505303
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发表时间：
2010-12
期刊：
影响因子：
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通讯作者：
Xuefeng Liu;D. Leadley
中科院分区：
文献类型：
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作者：
Xuefeng Liu;D. Leadley
通过减压化学气相沉积，在松弛的 Si0.2Ge0.8 虚拟衬底上生长了应变对称的 Ge/Si0.35Ge0.65 多量子阱 (MQW) 结构。所生长的 Ge/Si0.35Ge0.65 MQW 结构的单周期厚度为 25 nm (14 nm/11 nm)，在氮气环境中在 550 至 750 °C 的不同温度下进行退火。通过高分辨率X射线衍射研究了热稳定性和相互扩散特性。当退火温度≤600℃时，在Ge/Si0.35Ge0.65 MQW结构中没有观察到明显的相互扩散或应变弛豫，而当温度升高到650℃以上时，开始发生相互扩散。通过分析 Ge/SiGe 周期性卫星在 650–750 °C 温度下记录的强度的衰减率，获得相互扩散系数。对于平均 Ge 成分为 85 at% 的应变 Ge/Si0.35Ge0.65 MQW 结构，提取的活化能为 3.08 ± 0.1 eV。
A strain-symmetrized Ge/Si0.35Ge0.65 multiple quantum well (MQW) structure has been grown on a relaxed Si0.2Ge0.8 virtual substrate by reduced pressure chemical vapour deposition. The as-grown Ge/Si0.35Ge0.65 MQW structure with one period thickness of 25 nm (14 nm/11 nm) was annealed in nitrogen ambient at different temperatures from 550 to 750 °C. The thermal stability and interdiffusion properties were studied by high-resolution x-ray diffraction. No obvious interdiffusion or strain relaxation in the Ge/Si0.35Ge0.65 MQW structure was observed for annealing temperatures ⩽600 °C, while the onset of interdiffusion occurred as the temperature was increased to above 650 °C. The interdiffusion coefficient was obtained by analysing the decay rate of Ge/SiGe periodic satellites in the recorded intensity at temperatures 650–750 °C. The extracted activation energy was found to be 3.08 ± 0.1 eV for the strained Ge/Si0.35Ge0.65 MQW structure with an average Ge composition of 85 at%.