Research on functional electronic devices based on straind-Si on SiGe alloy substrates

本研究的目的是在Ge组分均匀的国产SiGe衬底上实现具有上级电学性能的应变控制Si基异质结。首先，我们尝试开发了一种基于原位监测系统的晶熔界面位置和温度反馈控制系统。通过对CCD图像的二值化和微分，实现了界面位置的自动识别。利用新开发的系统，我们成功地生长出成分均匀的SiGe。为了提高晶体质量，我们系统地改变了晶体-熔体界面附近的温度梯度。结果，系统的X射线摇摆曲线的线宽的减小和强度的增加被确认，推测是由于抑制了成分过冷。在国产SiGe衬底上，采用分子束外延技术生长了具有应变Ge沟道的调制掺杂结构。虽然没有实现载流子迁移率的提高，但应变的可控性得到了确认。

The purpose of this research is to realize strain-controlled Si-based heterostructures with superior electronic properties on homemade SiGe substrates wish uniform Ge composition.Firstly, we tried to develop a feedback control system of the crystal-melt interface position and temperature based on in-situ monitoring system. Automatic recognition of the interface position was successful by binarization and differentiation of the CCD image. By utilizing newly developed system, we succeeded in growing SiGe with uniform composition. To improve the crystal quality, we systematically changed the temperature gradient at around the crystal-melt interface. At a result, systematic decrease of the line-width of the X-ray rocking curve and increase of the intensity were confirmed presumably due to the suppression of constitutional supercooling. In addition, crystal quality was found to be strongly dependent on the orientation of the seed crystal.On homemade SiGe, modulation doped structure with strained-Ge channel was grown by molecular beam epitaxy. Although improved carrier mobility was not achieved, controllability of strain was confiemed.