The Hydrogenation Impact on Electronic Properties of p-Diamond/n-Si Heterojunctions

The undoped polycrystalline diamond films (PDFs) have been deposited on n-type silicon (Si) by Hot Filament Chemical Vapor Deposition (HF CVD) technique. The reaction gases are a mixture of methane and hydrogen. The obtained PDFs were characterized by scanning electron microscopy (SEM) and Raman spectroscopy which, in addition to the diamond phase, also confirms the presence of sp2 hybridized carbon bonds. As-grown CVD diamond layers are hydrogen terminated and show p-type conductivity. The effect of the level of hydrogenation on the electrical properties of p-diamond/n-Si heterojunctions has been investigated by temperature dependent current-voltage (J-V/T) characteristics. The obtained results suggest that the energy distribution of interface states at the grain boundary (GB) subjected to hydrogenation becomes shallower, and the hole capture cross-section can be reduced. Hydrogenation can lead to a significant reduction of the GB potential barrier. These results can be interesting from the point of view of hydrogen passivation of GBs in microelectronics.

Automated summary

Undoped polycrystalline diamond films were deposited on n-type silicon using the HF CVD technique. The presence of sp2 hybridized carbon bonds in the diamond layers was confirmed, and hydrogenation was found to affect the electrical properties of the heterojunctions. Hydrogenation was shown to reduce the potential barrier at the grain boundaries, which may have implications for hydrogen passivation in microelectronics.