Self-assembling formation of silicon quantum dots with a germanium core by low-pressure chemical vapour deposition
Self-assembling formation of silicon quantum dots with a germanium core by low-pressure chemical vapour deposition
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DOI：
10.1088/0957-4484/14/4/301
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发表时间：
2003-04-01
期刊：
影响因子：
3.5
通讯作者：
Miyazaki, S
中科院分区：
文献类型：
--
作者：
Darma, Y;Takaoka, R;Miyazaki, S
通过控制低压化学气相沉积（LPCVD）的早期阶段，交替使用纯甲硅烷和5%的锗烷稀释的氦气，研究了纳米级硅点的形成与锗的核心上的SiO2层。从原子力显微镜观察和X-射线光电子能谱测量，Ge的选择性生长的预生长的Si点和随后的完全覆盖与Si帽已被证实。横截面的透射电子显微镜图像已经示出了与半球形预生长的Si点相比，形成孤立的球形纳米晶与Ge芯，这意味着在包层Si和Ge芯之间的界面处的高结构应变。拉曼散射光谱表明，在LPCVD过程中，Ge芯与Si/Ge芯的界面处发生了部分成分混合。
The formation of nanometre-scale silicon dots with a germanium core on an ultrathin SiO2 layer has been studied by controlling the early stages of low-pressure chemical vapour deposition (LPCVD) alternately using pure monosilane and 5% germane diluted with helium. From atomic force microscope observations and x-ray photoelectron spectroscopy measurements, the selective growth of Ge on pregrown Si dots and subsequent complete coverage with a Si cap have been confirmed. Cross-sectional transmission electron microscope images have shown the formation of isolated spherical nanocrystallites with Ge cores in contrast with hemispherical pregrown Si dots, implying a high structural strain at the interface between cladding Si and the Ge core. For multiply stacked structures of the dots with a Ge core, Raman-scattering spectra indicate that compositional mixing occurs partly at the Si/Ge-core interface during LPCVD.