Diamond MESFET performance improvement by layout optimisation

Hydrogen terminated diamond is a promising material for metal semi-conductor field effect transistor (MESFETs) fabrication and research effort is focused on diamond quality improvement. In this reported work, the focus of attention is on device layout and structure to improve RF performances, designed on the basis of diamond physical properties, taking into account the characterisation of previously fabricated devices. Significant increase of current gain cutoff frequency f_T, from 3.4 to 6.7 GHz, has been obtained, while maximum oscillation frequency f_MAX is raised from 10.4 to 11.8 GHz.