权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

STUDY ON INFRA-RED OPTICAL DEVICES BY Si_<1-x>Ge_x HETERO-STRUCTURES

Si_<1-x>Ge_x异质结构红外光学器件的研究

基本信息

批准号：
06555005
负责人：
YASUDA Yukio
金额：
$ 6.53万
依托单位：
NAGOYA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

项目摘要

In this study, we have studied the fabrication technology of Si_<1-x>Ge_x/Si (100) hetero-structures and the charactersitics of Si_<1-x>Ge_x layrs in order to realize infra-red optical devices. Research results are as follows.1.By doping Sb impurities in MBE growth of Si_<1-x>Ge_x layrs, Ge segregation is suppressed and the strain-relaxation of Si_<1-x>Ge_x layrs is enhanced at the Ge fractions below 0.17. At x=1, however, strain-relaxation is suppressed. These results suggest that the strain-relaxation process is dominated by the increase in strain and the suppression of migration of Ge atoms by Sb atoms on the surface.2.The amount of doped Ga impurities in p-Si_<1-x>Ge_x layrs linealy increases as increasing the Ge fractions. Considering the adsorption and the segregation mechanism of Ga atoms in the growth, the adsorption and the incorporation rate of Ge atoms were estimated to be 2 and 40 times as large as Si atoms, respectively.3.TO-phonon-assisted bound exciton luminescence is observed at a temperature of 13K in heavily doped p-Si_<1-x>Ge_x/Si (100) systems. The bandgap of the p-Si_<1-x>Ge_x layrs is estimated by 1.124 and 1.092 eV for x=0.05 amd 0.1, respectively.4.Valence-band splittings of strained p-Si_<1-x>Ge_x layres were observed in measurements of magnetoresistance. The separation between the valence bands has a linear dependnce on the Ge fraction and the measurement temperature.5.Strain-relaxd Si_<1-x>Ge_x layres were grown by two-step growth method. By this method, atomic mixing at Si_<1-x>Ge_x/Si (100) interfaces is suppressed and the chemical compositions are well controlled, comparing with conventioanl method. Moreover, crystalline quality is also improved. It was also found that there is an optimum thickness of first layrs to minimize the surface roughness.

本文研究了Si_<1-x>Ge_x/Si（100）异质结构的制备工艺和Si_<1-x>Ge_x层的特性，以实现红外光学器件。研究结果如下：1.在Si_ Ge_x层的MBE生长过程中掺入Sb杂质<1-x>，抑制了Ge的偏聚，并<1-x>在Ge含量低于0.17时增强了Si_ Ge_x层的应变弛豫。然而，在x=1时，应变弛豫被抑制。这些结果表明，应变弛豫过程主要由应变的增加和表面Sb原子对Ge原子迁移的抑制所控制。2.<1-x>随着Ge含量的增加，p-Si_ Ge_x层中Ga杂质的掺杂量线性增加。考虑到Ga原子在生长过程中的吸附和分凝机制，估计Ge原子的吸附和掺入速率分别是Si原子的2倍和40倍。3.在重掺杂p-Si_ Ge_x/Si（100）系统中，在13 K温度下观察到TO声子辅助的束缚激子发光<1-x>。当<1-x>x=0.05和0.1时，p-Si_Ge_x层的禁带宽度分别为1.124和1.092 eV<1-x>。价带间距与Ge含量和测量温度呈线性关系。5.<1-x>采用两步生长法生长了应变弛豫Si_ Ge_x薄膜。与常规方法相比，该方法抑制了Si_<1-x>Ge_x/Si（100）界面的原子混合，并能很好地控制化学成分。此外，结晶质量也得到改善。研究还发现，存在一个最佳的第一层厚度，以尽量减少表面粗糙度。