Device modeling of high performance diamond MESFETs using p-type surface semiconductive layers

The operation of high-performance diamond MESFETs using thin p-type surface semiconductive layers of undoped hydrogen-terminated CVD diamond films has been simulated. We have used diffusion profiles of shallow acceptors to describe the surface conductive layer. In order to describe metal/hydrogen/diamond interfaces, we have assumed an incomplete contact model where an atomic scale gap (∼0.5 nm) is inserted between the metal and the diamond. The results of this model have been compared with those obtained from direct metal/diamond contact model. The experimental I-V characteristics have been realized with acceptor density of 1 × 10¹³ cm^-2, and the transconductance per unit gate width of diamond MESFETs with 1 μm gate length is predicted to be nearly 50 mS mm^-1 by using both complete and incomplete contact models.