GROWTH PYRAMIDS ON SI(111) FACETS - A CVD AND MBE STUDY

The morphology of growth pyramids on Si(lll) facets has been studied w ith an atomic force microscope. These facets with pyramids are formed upon chemical vapor deposition (CVD) growth on a hemispherical substra te. Spiral as well as concentric step edge patterns have been observed on the growth pyramids. Based on the step edge patterns the origin of the pyramids is attributed to different types of dislocations. Step e dge patterns indicate that growth during CVD is governed by step edge processes and that surface diffusion is not rate limiting. The complet ely different growth mechanism of molecular-beam epitaxy (MBE) is illu strated by MBE overgrowth of a silicon layer on top of the CVD layer. MBE growth parameters have been studied by comparing the growth pyrami d morphology with simulation results.