Enhancement-Mode InAlN/GaN Power MOSHEMT on Silicon with Schottky Tri-Drain Extension

This study demonstrates an enhancement-mode (E-mode) InAlN/GaN MOSHEMT on a silicon substrate with a Schottky tri-drain extension (STDE) to yield a large breakdown voltage ( text{V}_{text {BD}} ) while maintaining a low on-resistance ( text{R}_{text {on}} ). The E-mode operation is realized by a recessed tri-gate nanowire structure. The STDE functions as a drain-connected field plate (FP) to effectively distribute the electric field (E-field) around the drain contact edge, improving the text{V}_{text {BD}}. Moreover, through the metal of the STDE directly contacting the 2-D electron gas (2-DEG) from the sidewalls, a low specific text{R}_{text {on}} ( text{R}_{text {on, sp}} ) is achieved. The proposed device with a gate-to-drain length ( text{L}_{text {GD}} ) of 5~mu text{m} exhibits a threshold voltage ( text{V}_{text {TH}} ) of +0.9 V, large maximum drain current ( text{I}_{text {D, max}} ) of 815 ± 27 mA/mm, high text{I}_{text {on}}/text{I}_{text {off}} ratio of 1010, steep subthreshold swing (SS) of 67 mV/decade, superior text{V}_{text {BD}} of 830 V, and low text{R}_{text {on, sp}} of 0.74 ± 0.04~text{m}Omega cdot cm2. With text{L}_{text {GD}} of 10~mu text{m} , a text{V}_{text {BD}} of 1190 V is achieved, corresponding to a text{R}_{text {on, sp}} of 1.39 ± 0.07~text{m}Omega cdot cm2. These results reveal great potential for future E-mode power device applications.