Growth and characterization of freestanding p+ diamond (100) substrates prepared by hot-filament chemical vapor deposition

Abstract

Heavily B-doped p+diamond (100) thick films were grown by hot-filament chemical vapor deposition (HFCVD). Low resistivity (<3mΩcm) was successfully realized with high-rate growth conditions (1–4μm/h). The as-grown film surface exhibited step-bunching faces without non-epitaxial grains; lateral growth was maintained over thick films (>100μm). Freestanding crack-free films were prepared by removing the seed substrates via laser-cut and mechanical polishing processes. The X-ray diffraction rocking curve (004) spectrum showed the full-width at half maximum value of 25arcsec, equivalent to that of the seed substrates employed. Vertical Schottky barrier diodes showed clear rectifying actions with low leakage current level.