Low resistivity p+ diamond (100) films fabricated by hot-filament chemical vapor deposition

•Heavily B-doped diamond (100) films were fabricated by hot-filament CVD.•p+ films were grown coherently (pseudomorphic growth) without misfit dislocations.•Room temperature resistivity as low as 1 mΩ·cm was obtained.

By hot-filament (HF) chemical vapor deposition (CVD), heavily boron (B)-doped single-crystal diamond (100) films were fabricated and their structural and electrical properties were studied. We did not observe the soot formation, which is frequently observed and limits the performances in the case of microwave plasma (MWP) CVD. The B concentration was successfully controlled over the range from 1019 to 1021 cm− 3. Hillock-free films were obtained, whose mean surface roughness measured by atomic force microscopy (AFM) was less than 0.1 nm. From the reciprocal space mapping (RSM) around 113 diamond reflection, it was revealed that the films possess the smaller lattice expansion than that expected from the Vegard's law. The room-temperature resistivity was decreased lower than 1 mΩ·cm for B concentration ~ 1021 cm− 3. These results indicate that the HFCVD possesses large potential for fabricating the device-grade p+ diamond.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide