Improved double-recessed 4H-SiC MESFETs structure with recessed source/drain drift region

An improved double-recessed 4H-SiC MESFETs structure with recessed source/drain drift region was proposed. The recessed source/ drain drift region is to reduce channel thickness between gate and drain as well as eliminate gate depletion layer extension to source/ drain. The recessed source/drain drift region of the proposed structure can be realized with the formation of double-recessed gate region. The simulated results showed that the breakdown voltage of the proposed structure is 145 V compared to 109 V of that of the published 4H-SiC MESFETs with double-recessed gate structure and yet maintain almost same saturation drain current characteristics. The output power density of the proposed structure is about 33% larger than that of the published double-recessed gate structure. The cut-off frequency (f(T)) and the maximum oscillation frequency (f(max)) of the proposed structure are 21.8 GHz and 81.5 GHz compared to 19.0 GHz and 76.4 GHz of that of the published double-recessed gate structure, respectively. (C) 2007 Elsevier B.V. All rights reserved.