Effect of the substrate bias in diamond deposition during hot filament chemical vapor deposition: Approach by non-classical crystallization

The effect of the substrate bias on the diamond deposition was studied using a hot filament chemical vapor deposition (HFCVD) reactor. Both growth rate of diamonds and sp < sup > 3 /sp < sup > 2 ratio increased with increasing the substrate bias from – 200 V to + 45 V. At + 60 V where the DC glow discharge occurred, however, the data deviated significantly from the tendency. These results were explained by the new concept of non-classical crystallization, where a building block of diamond growth is a charged nanoparticle rather than an atom. Based on the previously reported experimental confirmation of the gas phase generation of negatively-charged diamond nanoparticles, the bias effect on the diamond deposition behavior could be consistently explained.