纳米硅薄膜的研制

使用大量氢稀释硅烷,严格控制PECVD系统中的工艺参数,分别沉积出a-Si:H,nc-Si:H 以及μc-Si:H薄膜.使用HREM,Raman及X射线谱,探讨了nc-Si:H膜的结构特征.结果表明,它已符合国际上对于固体纳米材料的认识.由于结构上的新颖性,使它具有一系列鲜为人知的物性.     

ORDER ALLOY IN GexSi1-x/Si(100) STRAINED-LAYER SUPERLATFICES

The Ge_xSi_1-x/Si(100) strained-layer superlattices have been investigated by means of the transmission electron microscopy of the cross-sectional specimen (XTEM) and the high resolution electron microscopy (HREM), The order alloy with a period of modulation twice as large as the lattice constant along <100> zone axis has been found in the alloy layers of the superlattices with x≈0.4-0.5. This order struc-ture makes the superlattices inhomogeneously strained. The result of the compuler simulation shows that the order alloy exhibits an altemating stack of 2 monolayers of Ge atoms and 2 monolayers of Si atoms along the <100> zone axis. Thc calculated elastic strain energy of the disorder alloy reported in the litera-ture is very close to that of the order alloy along <100> zone axis. Thus, during the MBE growth of the alloy layers, both the disorder and order alloys can be formed along <100> zone axis.     

非晶硅薄膜晶化过程中微结构的分析

使用X射线衍射技术和高分辨率电子显微镜(HREM),分析研究了在非晶硅薄膜由非晶相向微晶相转化过程中其网络结构的变化特征,由此,给人们一个直观的信息,并加深对非晶硅薄膜微结构的认识。 关键词：     

SiO_2上多晶GeSi再结晶性质的研究

本文发展了一种SiO2上多晶GeSi再结晶的方法，研究了其再结晶性质．由RRH／VLP－CVD系统在SiO2上生长的性能优良的多晶GeSi材料，经能量为180keV，剂量为2×1014cm-2的Si+离子注入非晶化处理后，形成具有一定损伤分布的非晶层．由此，我们系统研究了多晶GeSi非晶化后的再结晶性质，认为Ge在再结晶过程中可能起了的诱导晶化作用；首次观察到GeSi晶粒的纵向生长行为；得到的GeSi晶粒大于同样条件下得到的多晶Si晶粒．本项研究为多晶GeSi在高速TFT器件及其它高速器件中的应用奠定了基础，并为制备GeSi量子线结构提供了一条可能的途径．     

SiO_2全封闭的硅量子线列阵

采用硅工艺的反应离了刻蚀、各向异性化学腐蚀、热氧化和超低压化学气相淀积生长技术，成功地在硅单晶衬底上制作了ＳｉＯ２全封闭结构的硅量产线列阵．扫描电镜观察清楚地显示了这种高质量的量子线结构．实验表明，通过热氧化过程可以非常有效地控制量子线的尺寸．     

ORDER ALLOY IN GexSi1-x/Si(100) STRAINED-LAYER SUPERLATFICES

The Ge_xSi_1-x/Si(100) strained-layer superlattices have been investigated by means of the transmission electron microscopy of the cross-sectional specimen (XTEM) and the high resolution electron microscopy (HREM), The order alloy with a period of modulation twice as large as the lattice constant along <100> zone axis has been found in the alloy layers of the superlattices with x≈0.4-0.5. This order struc-ture makes the superlattices inhomogeneously strained. The result of the compuler simulation shows that the order alloy exhibits an altemating stack of 2 monolayers of Ge atoms and 2 monolayers of Si atoms along the <100> zone axis. Thc calculated elastic strain energy of the disorder alloy reported in the litera-ture is very close to that of the order alloy along <100> zone axis. Thus, during the MBE growth of the alloy layers, both the disorder and order alloys can be formed along <100> zone axis.