Analysis and Optimization for Characteristics of Vertical GaN Junctionless MOSFETs Depending on Specifications of GaN Substrates

In this paper, the electrical performances for of vertical GaN junctionless metal–oxide–semiconductor-field-effect-transistors based on GaN substrate were investigated to improve the device characteristics. To improve the breakdown voltage (BV), the optimization process is performed using two-dimensional simulation technology computer-aided design. Because BV is strongly affected by the undoped GaN drift layer, gate length, and fin width, and it should be designed in views of them. The optimized device has 30.63 kA/cm² of the on-state drain current density 30.63 kA/cm² and 2,009 V of BV. As a result, the device characteristics for high-power and high-voltage applications can be further improved through the optimization and characterization used in this paper.