Delta-doped β-Ga 2 O 3 thin films and β-(Al 0.26 Ga 0.74 ) 2 O 3 /β-Ga 2 O 3 heterostructures grown by metalorganic vapor-phase epitaxy

We report on the silicon delta doping of metalorganic vapor-phase epitaxy grown β-Ga2O3 thin films using silane as a precursor. The delta-doped β-Ga2O3 epitaxial films are characterized using capacitance–voltage profiling and secondary-ion mass spectroscopy. The sheet charge density is in the range of 2.9 × 1012 cm−2 to 9 × 1012 cm−2 with an HWHM (towards the substrate) ranging from 3.5 nm to 6.2 nm. We also demonstrate a high-density (n s: 6.4 × 1012 cm−2) degenerate electron sheet charge in a delta-doped β-(Al0.26Ga0.74)2O3/β-Ga2O3 heterostructure. The total charge could also include a contribution from a parallel channel in the β-(Al0.26Ga0.74)2O3 alloy barrier.