Effect of Tl content on the growth of TlGaAs films by low-temperature molecular-beam epitaxy
Effect of Tl content on the growth of TlGaAs films by low-temperature molecular-beam epitaxy
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Tl含量对低温分子束外延生长TlGaAs薄膜的影响
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
Y. Ohtani
中科院分区：
文献类型：
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作者：
Y. Kajikawa;M. Kametani;N. Kobayashi;N. Nishimoto;Y. Yodo;Y. Kitano;Y. Ohtani
采用固体源分子束外延技术，在衬底温度为210 °C，As/Ga束等效压比为100时，在GaAs(001)衬底上生长了不同Tl含量的Tl-GaAs层。用卢瑟福背散射光谱、二次离子质谱仪和电子探针分析表征了Tl的含量。Nomarski显微镜观察表明，在Tl含量x=7.0%之前，TlxGa1-−xAs薄膜表面呈镜面状，而Tl含量为7.7%的样品表面出现了Tl液滴。当Tl含量x=6.4%时，X射线衍射谱显示出清晰的表面峰。我们利用X射线衍射仪的数据，用两种不同的方法估算了单晶生长转变为多晶生长时的外延厚度。在一种方法中，我们测量了TlGaAs层的渐进式刻蚀后外延峰的衍射峰强度的变化。另一种是在模拟的基础上...
TlGaAs layers with various Tl contents have been grown on GaAs(001) substrates by solid-source molecular-beam epitaxy at a substrate temperature of 210 °C and an As/Ga beam equivalent pressure ratio of 100. The Tl content was characterized by Rutherford backscattering spectrometry, secondary-ion mass spectrometry, and electron microprobe analysis. Nomarski microscope observation revealed that the surfaces of the TlxGa1−xAs layers were mirror like until a Tl content of x=7.0% while Tl droplets appeared on the surfaces of samples with a Tl content of x=7.7%. X-ray diffraction (XRD) curves showed clearly resolved epi-layer peaks until a Tl content of x=6.4%. We estimated the epitaxial thickness hepi, at which single-crystalline growth is replaced by polycrystalline growth, by two different methods using the XRD data. In one method we measured the change in diffracted intensity of the epi-layer peak after progressive gradual etching of the TlGaAs layers grown. The other was on the basis of a simulation of the...