Ga2O3 MOSFETs Using Spin-On-Glass Source/Drain Doping Technology

We report the first demonstration of source/drain (S/D) doping using tin (Sn) doped spin-on-glass (SOG) on Ga2O3 power MOSFET. The effectiveness of SOG doping is verified by a comparative experiment on semi-insulating Ga2O3 substrates. A specific contact resistance of rho c = 2.1 +/- 1.4x10(-5) Omega.cm(2) is obtained to the SOG doped layer. The thermal diffusion behavior of Sn in Ga2O3 is investigated as well. MOSFETs with SOG S/D doping is fabricated on 200-nm epitaxial Ga2O3 layer with an average effective doping of 2x10(17)/cm(3). An increased peak output drain current density of 40mA/mmis achieved due to reduced S/D resistance. The maximum transconductance (gm) is extracted to be 1.23 mS/mm for a device with L-g = 2 mu m. The device also shows a large ON/OFF ratio of 10(8) and breakdown voltage of 382 V.