A novel SOI-MESFET structure with double protruded region for RF and high voltage applications

Abstract

This study sets out to analyze a novel SOI MESFET structure by modifying the shape of the buried oxide. In order to obtain improved electrical performances in SOI-MESFET devices, we have proposed a new structure in which a double protruded region with a groove (DPG) in the buried oxide is created. This strategy reduces the carrier׳s concentration in the channel and improves the breakdown voltage. The proposed structure is analyzed and optimized carefully by 2-D numerical simulation and compared with a conventional SOI MESFET (C-SOI MESFET). It shows one extra peak created in the electric field distribution near the drain side which improves the breakdown voltage and the maximum output power density (Pmax) 46% and 33% in comparison with the C-SOI MESFET, respectively. Also, the gate-source and the gate-drain capacitances decrease due to reduction of the carrier concentration in the channel. Therefore, the RF characteristics of proposed structure such as Maximum Available Gain (MAG), h21 (current gain), and Unilateral power gain (U) improve about 13%, 24%, and 12%, respectively in comparison with the C-SOI MESFET.