Structural Study and Mechanisms of Nucleation and Growth of Diamond Crystal Grown on Scratched Si(100) substrate by hot Filament Chemical Vapor Deposition Method

摘要

CVD diamond films deposited on intentionally scrateched Si(100) substrates, both free of and containing seeded diamond crystals, have been investigate by x-ray diffraction and transmission electron microscopy techniques. Films grown on substrate scratchd yba diamond paste and containing seeded diamond crystals appear to distribute on te substrate well and show little evidence of any existing voidin the microstructure. The film microstructure is comprised of sparsely populated diamond crystals of faceted morphology embedded in the matrix of graphite and amorphus carbon. Substrat scrateche either by a diamond paste or by an abrading tool, but containing no seeded crystal, develops a film wih a high density fo diamond particle and a lower concentration of graphite and amporphous carbon. Diamond particles found in these tow types of substrate show difference in their crystal morphology; exhibiting faceted crystal morphology on substrate treated with abrading tool and complex crystal morphology, with ragged surfaces on substrate treatd with diamond pasted. A distinctive feature found common to diamond of either crystal morphology is the appearances of zigzag network of constituent twins. The observed structural features of grown diamond crystals are explained on the basis of an exising nucleation and growth mechanism suggested for the freezing of diamond cubic crystal from melt.