MESFETs on H-terminated single crystal diamond

Epitaxial diamond films were deposited on polished single crystal Ib type HPHT diamond plates of (100) orientation by microwave CVD. The epilayers were used for the fabrication of surface channel MESFET structures having sub-micrometer gate length in the range 200-800 nm. Realized devices show maximum drain current and trasconductance values of about 190 mA/mm and 80 mS/mm, respectively, for MESFETs having 200 nm gate length. RF performance evaluation gave cut off frequency of about 14 GHz and maximum oscillation frequency of more than 26 GHz for the same device geometry. © 2010 Materials Research Society.