In this paper a novel structure for silicon on insulator metal semiconductor field effect transistors (SOI MESFETs) is proposed. The proposed structure contains two symmetrical oxide boxes at both sides of gate metal and extended drift region into the buried oxide which is named SO-ED-SOI-MESFET. SO-ED stands for symmetrical oxide boxes and extended drift region. DC and radio frequency characteristics of the SO-ED are analyzed by 2-D numerical simulation and compared with conventional SOI MESFET (C-SOI MESFET) characteristics. The obtained results demonstrate the superiorities of the proposed structure over C-SOI MESFET including increased breakdown voltage, higher driving current and improved RF characteristics. The extended drift region improves the current capability by increasing the effective channel thickness. The oxide region boosts the breakdown voltage due to its high tolerable electric field. Also, RF performance of the device is enhanced because of modified gate-source and gate-drain capacitances in the proposed structure. Unilateral power gain, maximum available gain and current gain experience 63, 52 and 63.5% improvement by applying the proposed structure, respectively. Thus the proposed structure can be considered as a proper candidate for using in high power and high frequency applications.
