Lattice-strained Si thin films grown onto SiGe(110)/Si(110) are attracting because of their potential to realize high-speed transistors. In this study we observe surface morphology of Si/SiGe/Si(110) using scanning el...Lattice-strained Si thin films grown onto SiGe(110)/Si(110) are attracting because of their potential to realize high-speed transistors. In this study we observe surface morphology of Si/SiGe/Si(110) using scanning electron microscopy and we also observe microstructure of the identical position using cross-sectional transmission electron microscopy. These results reveal that crossing of stress-induced twins causes remarkable surface roughness. We propose using vicinal substrate to avoid this phenomenon and our successive experimental results are shown in this paper.展开更多
We deposited Ge films on Si substrates by molecular beam epitaxy (MBE) method. The specimens were annealed at around 750 C using microwave- plasma heating technique which we had reported before. After these pro- cesse...We deposited Ge films on Si substrates by molecular beam epitaxy (MBE) method. The specimens were annealed at around 750 C using microwave- plasma heating technique which we had reported before. After these pro- cesses, we carried out special scanning transmission electron microscopic (STEM) observation. The moiré between the crystal lattices and the scanning lines controlled by STEM was utilized to show lattice-spacing distribution. The results exhibited that we were succeeded in forming lattice-relaxed Ge thin films. It was also recognized that this STEM moiré technique is very useful to observe lattice-spacing distribution for large area with high resolution.展开更多
Strain-relaxed SiGe is an attractive material for use as a substrate of strained Si, in which carrier mobility is higher than that of bulk Si. The concept of this study is the use of porous Si as a sponge like substra...Strain-relaxed SiGe is an attractive material for use as a substrate of strained Si, in which carrier mobility is higher than that of bulk Si. The concept of this study is the use of porous Si as a sponge like substrate so that a SiGe lattice can relax without introducing dislocations. We produced porous Si specimens by electrochemical anodization and annealed them under a H2 atmosphere. Then, SiGe thin films were grown by gas-source molecular beam epitaxy. We observed the microstructure of the specimens using transmission electron microscopy. The result showed that we succeeded in producing a single-crys- tal continuous Si0.73Ge0.27 film with a 10% relaxation ratio and a low dislocation density on porous Si.展开更多
文摘Lattice-strained Si thin films grown onto SiGe(110)/Si(110) are attracting because of their potential to realize high-speed transistors. In this study we observe surface morphology of Si/SiGe/Si(110) using scanning electron microscopy and we also observe microstructure of the identical position using cross-sectional transmission electron microscopy. These results reveal that crossing of stress-induced twins causes remarkable surface roughness. We propose using vicinal substrate to avoid this phenomenon and our successive experimental results are shown in this paper.
文摘We deposited Ge films on Si substrates by molecular beam epitaxy (MBE) method. The specimens were annealed at around 750 C using microwave- plasma heating technique which we had reported before. After these pro- cesses, we carried out special scanning transmission electron microscopic (STEM) observation. The moiré between the crystal lattices and the scanning lines controlled by STEM was utilized to show lattice-spacing distribution. The results exhibited that we were succeeded in forming lattice-relaxed Ge thin films. It was also recognized that this STEM moiré technique is very useful to observe lattice-spacing distribution for large area with high resolution.
文摘Strain-relaxed SiGe is an attractive material for use as a substrate of strained Si, in which carrier mobility is higher than that of bulk Si. The concept of this study is the use of porous Si as a sponge like substrate so that a SiGe lattice can relax without introducing dislocations. We produced porous Si specimens by electrochemical anodization and annealed them under a H2 atmosphere. Then, SiGe thin films were grown by gas-source molecular beam epitaxy. We observed the microstructure of the specimens using transmission electron microscopy. The result showed that we succeeded in producing a single-crys- tal continuous Si0.73Ge0.27 film with a 10% relaxation ratio and a low dislocation density on porous Si.
