标题: 磊晶成长高品质锗薄膜于砷化镓基板之研究
Study of High Quality Ge Epitaxial Film on GaAs Substrate
作者: 郭俊佑
Kuo, Chun-Yu
张翼
Chang, Yi
材料科学与工程学系
关键字: 磊晶;锗;砷化镓;Ge;GaAs;UHVCVD
公开日期: 2011
摘要: 随着传统矽半导体元件不断的以缩小尺寸,达到节省成本与加速运算速率的目标已渐渐遇到瓶颈,如:漏电流的提高、通道传导速率的降低。为解决问题,科学家便开始寻求其他材料来代替传统的矽,拥有高速电子传导率的三五族复合物马上就受到科学家的注意,但是为了要提升互补式金氧半元件的效率,拥有高速电洞传导率的锗材料也受到相当的重视。
本实验是将锗薄膜磊晶成长于砷化镓基板上,利用改变成长温度、压力等因素来使成长出的锗薄膜拥有良好的特性,从材料分析里可以了解锗薄膜磊晶在砷化镓基板后的结晶性、是否有缺陷存在,以及锗薄膜的表面平整度,接着从萤光光谱仪与载子浓度分析仪的结果发现,我们的结构在萤光光谱仪产生峰值,并且从载子浓度分析仪得知锗薄膜有从砷化镓基板自体扩散的砷与镓原子,最后使得结构为n-type,未来我们成长的高品质锗薄膜于砷化镓基板上可以应用于的互补式金氧半导体元件的整合,以提升整体的效率。
The practice of scaling in microelectronics has allowed constant improvements in the cost, performance, and functionality of Si-based integrated circuits. However, as feature size is below 100nm, the performance improvement attribute to scaling is diminished. At first, the gate leakage current increases through ultra-thin SiO2. Secondly, channel mobility is degraded in the high electrical field. III-V compounds have attracted lots of attention because of their high electron mobility. However, III-V materials still suffer from low hole mobility, and it is very important to find a new material with high hole mobility to extend their performance towards the applications of complementary metal-oxide-semiconductor (CMOS) devices. Ge attracted lots of attentions because of its high hole mobility.
In this study, high-quality epitaxial Ge film was deposited on GaAs substrate by ultrahigh vacuum chemical vapor deposition (UHVCVD). Take different growth factors into account to deposit high quality Ge epitaxial layer on GaAs substrate. In-depth characterizations of Ge film structure, optical and electrical properties, and doping conditions were carried out by x-ray diffraction (XRD), cross-sectional transmission electron microscopy (TEM), scanning electron microscope (SEM), atomic force microscopy (AFM), photoluminescence (PL), and electrochemical capacitance voltage (ECV) profiling. In the end, the Ge epitaxial film is n-type with a donor concentration generated by self-doping. It reveals that the electrons in L valley recombine with holes in the valence band, and appearance of the direct band gap emission in the Ge epitaxial film on GaAs substrate. This high quality n-type Ge epitaxial film can be used for the fabrication of p-channel MOSFET, and useful for the future integration of Ge p-channel and GaAs n-channel electronic devices on Si template.
URI: http://140.113.39.130/cdrfb3/record/nctu/#GT079718523
http://hdl.handle.net/11536/44911
显示于类别:Thesis