  Gallium Oxide (Ga2O3) has a huge potential on the power device for its high
breakdown filed and good transport properties. beta-Ga2O3 as the thermodynamics
stable phase, has been demonstrated to form high electron mobility transistor
(HEMT) through delta-doping in the barrier due to its none-polar property.
Following the development in III-V HEMT which turns from delta-doping-induced
to polarization-induced 2DEG, an alternative method based on III-N
materials/beta-Ga2O3 heterostructure is proposed that utilizing the
polarization difference on the interface. Further requirements of electric
field and conduction band difference show that only nitrogen (N)-polar AlN on
beta-Ga2O3 can form the channel and hold large 2DEG concentration on the
interface. Compared with conventional metal-polar AlN/GaN HEMT, the proposed
N-polar AlN/beta-Ga2O3 HEMT show a much larger 2DEG concentration, the
spontaneous-polarization-dominated electric field, better DC output
performance, as well as higher breakdown voltage. This study provides a new
research approach that shifting from delta-doping-induced to
polarization-induced on beta-Ga2O3-based HEMT, which can also be a guideline
for community excavating the application potential of Ga2O3.
