Sub-micron gate length MESFET on hydrogen terminated polycrystalline diamond

Surface channel MESFETs with submicron gate length (325-500 nm) were realized on hydrogen terminated polycrystalline diamond having 1-2 m average grain size. Device operation were characterized both in dc and under rf excitation. Typical maximum drain current values normalized to the gate width was higher then 35 mA/mm with transconductance maximum values of about 5 mS/mm. In the rf regime, a maximum current gain cut off frequency of 1.5 GHz and a maximum power gain frequencies of 5.2 GHz are obtained