Epitaxial regrowth and characterizations of vertical GaN transistors on silicon

We report the fabrication of fully-vertical GaN-based metal-oxide-semiconductor field-effect transistors (V-MOSFETs) on Si. A alt;iagt;palt;/iagt;-GaN current aperture was introduced in the vertical device epi-structure using plasma-based dry etching and epitaxial regrowth technique to control the vertical current conduction. The fabricated V-MOSFET exhibited drain current density of 2.5 kA/cmalt;supagt;2alt;/supagt; with ON-resistance (alt;iagt;Ralt;subagt;ONalt;/subagt;alt;/iagt;) of 4.3 mΩ-cmalt;supagt;2alt;/supagt;. The transfer characteristics of the device showed a peak trans-conductance (alt;iagt;Galt;subagt;m,maxalt;/subagt;alt;/iagt;) of 248 S/cmalt;supagt;2alt;/supagt; with a threshold voltage (alt;iagt;Valt;subagt;thalt;/subagt;alt;/iagt;) of -18.7 V during OFF-to-ON state sweeping. However, a blocking voltage of 36.5 V (drain current density 0.3 kA/cmalt;supagt;2alt;/supagt;) was observed under an OFF-state condition of the device which needs further improvement for the high-power device applications.