Microstructural Studies Of Laser Enhanced, Filament Assisted Deposition Of Diamond Films

Abstract

Crystalline diamond was deposited on on silicon (100) substrates at -750° C by hot filament (2000° C) decomposition of methane and hydrogen (0.5 to 5 % CH4 in Hydrogen) mixtures between 20 to 60 ton. The crystalline diamond film deposited by the hot filament technique is rich in morphology and show considerable diversity in carbon -carbon bonding primarily due to the inhomogenuities in the deposition process. The morphology of diamond crystals show cubic or octahedral structures at low substrate temperatures T <800° C. These structures can be controlled by the temperature gradient surrounding the substrate material. The deposited films are characterized by TEM and Raman techniques. Amorphous carbon surrounds the intergranular regions of the diamond crystals. Preliminary results of irradiation of the CVD diamond film with a XeC1 UV-eximer laser selectively removes the sp2 bonded carbon component, improving the quality of the film.