Double Gate 180V-128mA/mm SiC-MESFET for Power Switch Applications
The potential of SiC MESFETs has been demonstrated for high frequency applications on several circuits in the 1-5 GHz frequency range. Although MESFET structures are conventionally used for RF applications, in this paper we report a low voltage (180V) power switch and its current limiting application based on a double gate MESFET structure, showing enhanced forward and blocking capabilities. The reported devices utilize a thin highly doped p-type layer implanted at high energy as buffer layer. Various layouts have been fabricated, varying the gate length; with either a single gate (p-buried layer connected to source) or double gate (one Schottky, and the second on the P-buried layer). Gate RESURF field-plate variation has been also included at the gate electrode. The I(V) electrical characterization validates the double gate configuration benefits. This double gate structure shows a higher gate transconductance than the single gate one. High voltage measurements in conducting mode (180V, 160mA/mm, 30W/mm) confirm the operation of the MESFET as a current limiting device, with excellent gate control capabilities at temperature up to 190°C.
Robert P. Devaty, David J. Larkin and Stephen E. Saddow
D. Tournier et al., "Double Gate 180V-128mA/mm SiC-MESFET for Power Switch Applications", Materials Science Forum, Vols. 527-529, pp. 1243-1246, 2006