MICROWAVE-POWER MESFET ON 4H-SIC

We present static and microwave characterization of NIESFETs processed on n(+) 4H-SiC wafers supplied by Cree Research. An eight-level techn ology including airbridge interconnections has been performed. Transis tors with total gate width up to 6 mm and 1.2 mu m gate length optical ly designed are obtained. High breakdown voltage (up to 140 V) and hig h drain current (up to 0.7 A) show the high power capability of the tr ansistors. RF characterization was performed. Because of the use of a conductive substrate, parasitic capacitances account for the relativel y low values of f(T) and f(max) (4 and 9 GHz, respectively). Power mea surements were carried out at 1 and 2 GHz in cw. Output powers up to 1 .7 W mm(-1) were measured with a power added efficiency of 37% at 2 GH z. (C) 1997 Elsevier Science S.A.