Characterization and Modeling of Hydrogen-Terminated MOSFETs With Single-Crystal and Polycrystalline Diamond

The mechanism of hydrogen-terminated (H-terminated) single-crystal and polycrystalline diamond metal-oxide field-effect transistors (MOSFETs) is investigated in this letter. In order to characterize the complicated p-type surface layer in H-terminated diamond MOSFETs, both p-type acceptors and the C-H dipole effect are considered in our model. Simulated hole distribution and band bending are used to illustrate the operation mechanism in the surface region. Simulated results by using the proposed model match well with both measured I-V and transfer characteristics of these two kinds of diamond MOSFETs. Moreover, channel lattice temperature distribution reveals that self-heating effect-induced slight current collapse occurs in the polycrystalline diamond MOSFET at I
_ds
over 500 mA/mm due to relatively lower thermal conductivity. Finally, the lateral electric field and hole velocity distribution under the gate electrode are given to aid future research.