High‐Quality Si‐Doped β‐Ga 2 O 3 Films on Sapphire Fabricated by Pulsed Laser Deposition

Pulsed laser ablation is used to form high‐quality silicon‐doped β‐Ga 2 O 3 films on sapphire by alternatively depositing Ga 2 O 3 and Si from two separate sources. X‐ray analysis reveals a single crystallinity with a full width at half maximum for the rocking curve around the (−201) reflection peak of 1.6°. Silicon doping concentration is determined by elastic recoil detection analysis (ERDA), and the best electrical performance is reached at a Si concentration of about 1 × 10 20 cm −3 , using optimized deposition parameters. It is found that a high crystalline quality and a mobility of about 2.9 cm 2 (V s) −1 can be achieved by depositing Si and Ga 2 O 3 from two separate sources. Two types of Schottky contacts are fabricated: one with a pure Pt and one with a PtO x composition. Electrical results from these structures are also presented.