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 Ga
₂
O
₃
power MOSFET. The effectiveness of SOG doping is verified by a comparative experiment on semi-insulating Ga
₂
O
₃
substrates. A specific contact resistance of ρ
_c
= 2.1±1.4×10
^-5
Ω·cm
²
is obtained to the SOG doped layer. The thermal diffusion behavior of Sn in Ga
₂
O
₃
is investigated as well. MOSFETs with SOG S/D doping is fabricated on 200-nm epitaxial Ga
₂
O
₃
layer with an average effective doping of 2×10
¹⁷
/cm
³
. An increased peak output drain current density of 40 mA/mm is achieved due to reduced S/D resistance. The maximum transconductance (g
_m
) is extracted to be 1.23 mS/mm for a device with L
_g
= 2μm. The device also shows a large ON/OFF ratio of 10
⁸
and breakdown voltage of 382 V.