Simulation of trench-based InGaAs LDMOSFET with improved performance

The structure of a conventional laterally diffused MOSFET (LDMOSFET) build on InGaAs is modified by placing trenches in the epitaxial layer. The gate of the proposed device (LDMOSFET) is placed in a oxide (Al₂O₃) trench between the source of the structure for creating twice channels in the p-base. Parallel conduction of twice channels leads to increase in drain current, higher transconductance, lower threshold-voltage, and decrease in on-resistance. The proposed device also has twice trenches of oxide which are placed in the drift region on both sides of gate electrode to enhance the reduced-surface-field (RESURF) effect for the improvements in breakdown voltage (BV). Using two-dimensional (2-D) numerical simulations, it is explained that the proposed device LDMOSFET gives 1.55 times increase in drain current, 14% reduction in threshold-voltage, 90% increase in transconductance, 33% lower on-resistance, and 2.2 times enhancement in breakdown voltage (BV) in comparison to the planar LDMOSFET for identical device length.