Growth of polycrystalline diamond on titanium nitride on silicon substrates using negative bias assisted CVD

Hot filament chemical vapour deposition (HFCVD) was used to grow adherent diamond films onto titanium nitride interlayers (TiN) deposited on (110) silicon substrates. TiN films were deposited using magnetron sputtering. Diamond films were subsequently grown using a bias assisted HFCVD system. We have found that when a DC bias was applied to the substrate in the range between 200-300V the nucleation density increased dramatically. The effects of negatively biasing the substrate on the nucleation density and growth of diamond are reported. The morphology of diamond crystallites and early stages of diamond nucleation were studied using scanning electron microscopy (SEM). After the initial nucleation stage, continuous diamond films were grown under standard process conditions for a period of 5 hrs. However, TiN on silicon substrates has a tendency of delaminating and cracking at CVD diamond growth temperatures commonly employed. Micro Raman analysis revealed that good quality diamond films have been deposited, as evident from a characteristic diamond peak at 1333 cm -1. The structure of both diamond and TiN films has been identified using X-ray diffraction (XRD) method and the results are reported.