Negative substrate-bias effects on diamond growth have been investigated using combustion flame synthesis. Diamond coatings with highly oriented crystals [{100}facets] or with a smooth surfaces were produced following the different deposition conditions. Specially, the heteroepitaxial,srowth of diamond on a carbide tungsten substrate was observed by scanning electron microscopy (SEM). The advantage of this method is that diamond grows on itself to achieve large-single crystal growth. These results are discussed with reference to competing heteroepitaxial growth of diamond. The role of negative substrate bias in nucleation and orientation of diamond crystallinity is also discussed.