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

Abstract

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 PtOx composition. Electrical results from these structures are also presented.

Reverse‐Bias Electroluminescence in Er‐Doped β‐Ga2O3 Schottky Barrier Diodes Manufactured by Pulsed Laser Deposition

“…We use a nominally undoped ZnO layer to equilibrate the conduction bands of ZnO and β-Ga 2 O 3. [11] Doping of gallium and zinc oxides is implemented by an alternative ablation procedure, [12] using highly pure Ga 2 O 3 , Ga 2 O 3 :1 wt% Si, ZnO, and Er 2 O 3 targets. DOI: 10.1002/pssa.202100610…”

“…Further details of the β-Ga 2 O 3 layer fabrication can be found in the previous study. [12] To form an array of Schottky barrier diodes (SBD), upper Pt contacts were RF magnetron sputtered in Ar ambient through a shadow mask (0.53 mm hole diameter) on top of the β-Ga for the non-Er-doped films with or without the ZnO layer (curves 2 and 3 in the inset, respectively) are the same (0.21 ) despite that one of them is grown directly on sapphire, while the other one is grown on the ZnO bottom layer.…”

Deposition of Ga2O3 thin films by liquid metal target sputtering

“…The known methods of Ga2O3 thin film deposition include metal-organic chemical vapor deposition [16], plasma-enhanced chemical vapor deposition [17], molecular beam epitaxy [18], atomic layer deposition [19], pulsed laser deposition [20], e-beam evaporation [9], and radio-frequency (RF) magnetron sputtering (MS) from ceramic Ga2O3 targets [21]. While MS is generally known for highquality coatings produced under well controlled and reproducible conditions [22][23][24], the drawback of the RF mode of sputtering is its impractically low sputtering rate.…”

The Effect of a Nucleation Layer on Morphology and Grain Size in MOCVD-Grown β-Ga2O3 Thin Films on C-Plane Sapphire

“…β-Ga 2 O 3 thin films have been grown by a variety of methods, such as pulsed laser deposition [ 10 , 11 ] and magnetron sputtering [ 12 ]; however, molecular beam epitaxy [ 13 , 14 ] and metalorganic chemical vapour deposition (MOCVD) [ 15 , 16 , 17 , 18 ] are the most promising methods for high deposition rates and high-quality device fabrication. MOCVD in particular has the advantage of high growth rates (up to 10 μm/h) with sub-nanometre surface roughness [ 16 ].…”