High-Quality Si-Doped β-Ga2O3 Films on Sapphire Fabricated by Pulsed Laser Deposition

Pulsed laser ablation is used to form high-quality silicon-doped β-Ga₂O₃ films on sapphire by alternatively depositing Ga₂O₃ 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 × 10²⁰ cm⁻³, using optimized deposition parameters. It is found that a high crystalline quality and a mobility of about 2.9 cm² (V s)⁻¹ can be achieved by depositing Si and Ga₂O₃ 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.