Dislocation-free formation of artificial cavities in Si single crystal

Cavities enclosed in silicon single crystals are formed by utilizing epitaxial growth on surfaces with microstructures consisting of parallel walls. The cavities accompany no dislocations and/or stacking faults in the surrounding crystal. Their as-formed cross-sectional shape is thin: the length being about 2 µm as compared with the width of 0.3 µm. The shape can be controllably changed by heat treatment. It becomes slightly fat and cocoon shaped at a temperature as low as 1000°C. The crystal defects are also not observed in the heat-treated samples.