Improved SOI-MESFET structures for enhanced efficiency and optimized DC/RF characteristics

In this paper, two new silicon on insulator metal-semiconductor field effect transistor (SOI-MESFET) structures are presented. Two parallel layers of oxide and aluminium are added at the gate edge of these structures. Also, in the buried oxide part of the Aluminium Edge and Silicon-Well MESFET (AESW-MESFET) structure, a silicon well and two aluminium layers are added. Moreover, and to improve the DC and RF characteristics, as compared to the Conventional MESFET (C-MESFET) structure, a silicon well and a silicon layer are added in the box oxide section in the Silicon Edge and Silicon-Well MESFET (SESW-MESFET) structure. By these changes, the value of the breakdown voltage in the normal structure has increased from 15.8 V to 33.1 V and 30.9 V in the proposed AESW-MESFET and SESW-MESFET structures, respectively. In addition, the maximum output power has been associated with a significant increase of 4.44 and 5.24 times, respectively. Compared to the C-MESFET, the proposed structures reduce gate-source and gate-drain capacitors and significantly increases conductivity. The cut-off frequency values are increased from 19.3 GHz (the normal structure) to 37.3 GHz and 35 GHz (the proposed structures), and the maximum oscillation frequencies are increased from 80 GHz to 154 GHz and 102.3 GHz. Therefore, the results show that the proposed structures have good performance and the ability to work at high power and high frequency.

Automated summary

This paper presents two new structures of silicon on insulator metal-semiconductor field effect transistors (SOI-MESFETs). By adding parallel layers of oxide and aluminium at the gate edge, a silicon well and two aluminium layers in the buried oxide part, and a silicon well and a silicon layer in the box oxide section, the proposed structures show improved breakdown voltage, maximum output power, cutoff frequency, and maximum oscillation frequency compared to the conventional MESFET structure. The results demonstrate that these structures have good performance and capability to operate at high power and high frequency.