Effects of pre-treated substrates on the growth morphology of diamond films prepared by the hot filament chemical vapor deposition method

Continuous polycrystalline diamond films are of interest because of their unique properties. A comparison study has been done on different abrasive pre-treatment methods used fur enhancing the nucleation of diamond crystallites onto silicon surfaces. We have used three methods for modification of Si surfaces: diamond paste for fine scratching and seeding; graded polishing paper for tough scratching; and a regular grinding tool for extreme roughness of the surface. All of these methods create defect sites, micron size pointed edges, valleys, and mesas on the surface. To study the role of seeding in nucleation, we have compared the results of scratched surfaces with or without seeding and a highly roughened surface. Our results show that the majority of nucleation events occur on a highly damaged and textured surface which contains a high density of sharp-edged sites.