EFFECT OF ULTRAHIGH NUCLEATION DENSITY ON DIAMOND GROWTH AT DIFFERENT GROWTH-RATES AND TEMPERATURES

A nucleation density in the range 108-1011 cm-2 is used for diamond film deposition on Si substrates. Diamond films, prepared by hot filament and microwave plasma chemical vapor deposition with deposition rate and temperature in the ranges of 0.05-2.5 μm per hour and 470-950 °C, respectively, were characterized by atomic force microscopy, scanning electron microscopy, and Raman spectroscopy. The surface roughness was studied as a function of deposition time, film thickness, grain size, and nucleation density. Films 1 μm thick were obtained with a mean surface roughness of 30 nm. It is found that the surface roughness is strongly dependent on nucleation density at the early stage of deposition.