High-Performance GaN HEMTs on Single Crystalline AlN Templates with a 230 nm Ultra-Thin Buffer and Al2O3/SiO2 Passivation

Single crystalline AIN templates are a promising candidate for fabricating
$\geq 1200$
V low-cost and high-performance GaN power HEMTs, which feature a high crystal quality and an ultra-thin buffer. In this work, GaN HEMTs have been successfully fabricated and evaluated on the 2-inch 500 nm single crystalline AIN templates, which are made on sapphire substrates through 1700 °C annealing. HEMTs with a 230 nm ultra-thin buffer demonstrate a high blocking voltage over 2700 V with gate-drain spacing L
GD
of 22
$\mu\mathrm{m}$
. Benefiting from the
$\text{Al}_{2}\mathrm{O}_{3}/\text{SiO}_{2}$
passivation, the fabricated HEMTs exhibit a
$< 15\%$
dynamic R
ON
degradation and a negligible threshold voltage V
TH
shift. This work proves that GaN HEMTs on the single crystalline AlN templates are likely to play an important role for future
$\geq 1200\ \mathrm{V}$
GaN products.