부산대학교 도서관

In this paper, a new efficient technique is used in silicon-on-insulator metal–semiconductor field-effect transistors (SOI MESFETs) to simultaneously increase the breakdown voltage and drain current and also improve the frequency parameters. This proposed structure is presented for SOI MESFET with; he displaced gate contact toward the source region and creating distinct silicon oxide packets with different sizes under both sides of the gate electrode inside the channel. Gate electrode displacement from the middle of the device toward the source rises the transistor breakdown voltage. Increasing the distance between the drain and gate electrodes decrease the accumulation of equipotential lines in the corner of the gate on the drain side, and reduces the field, thereby increasing the breakdown voltage in the suggested device. In addition, moving the gate metal toward the source has negative effects on the frequency performance, so by adding two oxide zones on both sides of the gate region the device parasitic capacitances are suppressed to compensate the frequency performance. Numerical simulations reveal that the breakdown voltage in the basic and suggested structures are about 15 and 30 V, respectively. Also, the drain current of the presented structure shows a significant increase compared to its basic counterpart. Here, the maximum output power density is 0.32 W/mm for the presented device and 0.12 W/mm for the basic structure, indicating 166% enhancement. Also, the RF specifications of the suggested structure, including maximum available power gain, current gain, unilateral power gain, and maximum stable gain, were improved by 21, 66, 50, and 52%, respectively, and cutoff frequency in the basic structure is 19.5, increased to 21.5 GHz by applied adaptations. [ABSTRACT FROM AUTHOR]