Low density of near-interface traps at the AI2O3/4H-SIC interface with Al2O3 made by low temperature oxidation of Al

We report on a very low density (<;5×10
¹¹
cm
^-2
) of near-interface traps (NITs) at the Al
₂
O
₃
/4H-SiC interface estimated from capacitance-voltage (CV) analysis of MOS capacitors. The aluminum oxide (Al
₂
O
₃
) is grown by repeated deposition and subsequent low temperature (200 °C) oxidation for 5 min of thin (1-2 nm) Al layers using a hot plate. We refer to this simple method as hot plate Al
₂
O
₃
. It is observed that the density of NITs is significantly lower in the hot plate Al
₂
O
₃
samples than in samples with Al
₂
O
₃
grown by atomic layer deposition (ALD) at 300 °C and in reference samples with thermally grown silicon dioxide grown in O
₂
or N
₂
O ambient.