An amazing semiconductor choice for high‐frequency FET: H‐terminated polycrystalline diamond film prepared by DC arc jet CVD

Abstract

AbstractWith the development of information and communication technology, conventional semiconductors such as Si and GaAs cannot satisfy the requirement of high‐frequency and high‐power electronic devices. By contrast, diamond film has been considered to be a potential material alternative due to the highest Johnson and Keyse figures of merit. In this paper, H‐terminated polycrystalline diamond films with different quality were prepared by DC arc jet CVD through adjusting the deposition conditions. The conductive behaviour of p‐type channel on H‐terminated diamond surface was compared and analyzed based on the N‐related impurity and spontaneous polarization model. After that, MESFETs (metal‐semi‐conductor field effect transistor) were fabricated on H‐terminated diamond and the radio frequency (RF) performance was evaluated. The cut off frequency (fT) of 11 GHz and the maximum oscillation frequency (fmax) of 18.5 GHz for MESFET in our situation were obtained. It was found that equivalent circuit elements were lower or comparable with the reported values for the FETs with the highest fT and fmax except the gate capacitance, which indicates that the carrier mobility should be improved further for high‐frequency devices application. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)