Effect of ultrahigh nucleation density on diamond growth at different growth rates and temperatures

Abstract

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.