Design and Analysis of High-k Dielectric Super junction Schottky Barrier
Diodes Beyond Unipolar Figure of Merit
Abstract
This study presents design guidelines for a high-k dielectric
Superjunction Schottky barrier diode (SBD) to further enhance the
already impressive unipolar power figure of merit (PFOM) of Ultra-wide
bandgap (UWBG) materials. We employed analytical modeling to optimize
the device parameters, accounting for the appropriate dielectric and
semiconductor dimensions including the aspect ratio and the dielectric
constant of the highk material. Our findings reveal that device
performance is intimately linked to structural dimensions and the
dielectric constant of the insulator. Specifically, we observed that the
dielectric superjunction SBD exhibits behavior akin to a conventional
SBD, where the effective doping density in the drift layer decreases by
a factor dependent on semiconductor and dielectric width, aspect ratio
and the dielectric constant of the insulator. We discuss optimal design
guidelines for achieving a 10 kV
β-Ga2O3 SBD with a PFOM of 50
GW/cm2, a significant improvement over the
conventional unipolar PFOM of 34 GW/cm2 for
β-Ga2O3. Additionally, we conducted a
comparative analysis of the switching energies between the superjunction
Schottky barrier diode and a conventional Schottky barrier diode.We
provide design guidelines to minimize switching energies for a desired
PFOM in β-Ga2O3 SBDs. This underscores
the immense potential of such structures in advancing vertical power
electronics to unprecedented levels of performance.