Step flow growth of β-Ga2O3 films on off-axis 4H-SiC substrates by LPCVD

Hu, Jichao; Xu, Bei; Zhang, Zihan; He, Xiaomin; Li, Lianbi; Cheng, Hongjuan; Wang, Jian; Meng, Jiaqi; Wang, Xi; Zhang, Chao; Jia, Renxu; Pu, Hongbin

doi:10.1016/j.surfin.2023.102732

Cited by 10 publications

(14 citation statements)

References 48 publications

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“…The presence of oxygen vacancies induced a Ga/O of β-Ga 2 O 3 epilayer of 0.68 via integrating with the area of Ga 2p and O 1s, which was slightly higher than Ga 2 O 3 crystal (0.67). 23 In addition, by the same way, the Ti/O ratio of samples 2#−4# (BaTiO 3 , SrTiO 3 , Ba 0.5 Sr 0.5 TiO 3 ) was estimated to be 0.34, 0.31, 0.32 respectively, while Sr/Ba ratio of sample 4# was nearly 0.96.…”

Section: Resultsmentioning

confidence: 87%

“…Characterizations and analyze of Ga 2 O 3 films.-The XRD characterization of sample 1# is shown in Fig. 1a, the diffraction peak near 41.70°corresponded to α-Al 2 O 3 (0006), and the peaks at 18.91°, 38.37°, and 59.02°originated from the β-phase of Ga 2 O 3 (−201), (−402), and (−603) (JCPDS 43-1012), 23,24 respectively. It reflects that the phase of LPCVD-grown β-Ga 2 O 3 films are preferentially selective orientation along the (−201) plane, and own decent crystal quality.…”

Section: Resultsmentioning

confidence: 99%

“…The primary peak (O I ) was occurred at 530.40 eV, which could be attributed to the Ga ions combined with oxygen ions to from Ga-O bonding. 23,26 The O II peak located at 531.41 eV could be related to the oxygen vacancies, 23,27 meanwhile, the O III peak (532.04 eV) may result from the C/O, O 2 , or H 2 O adsorbed on the surface. 23 The area percentage of O II peak was nearly 9.64%, which reflect the decent stability of LPCVD β-Ga 2 O 3 films in wet environment.…”

Section: Resultsmentioning

confidence: 99%

“…High purity gallium metal (⩾99.9999%) was used as gallium source, then, Oxygen (O 2 , 5 N) and Argon (Ar, 5 N) were used as oxygen precursor and carrier gas, respectively. 23,24 Further deposition details of β-Ga 2 O 3 could be found in previous work. 23 Following, a 30 nm thick perovskite oxides (BaTiO 3 , SrTiO 3 , Ba 0.5 Sr 0.5 TiO 3 (named as BSTO)) were then deposited on β-Ga 2 O 3 by RF PVD (Kurt J Lesker-PVD75) in O 2 ambience with a flow rate of 20 sccm.…”

Section: Methodsmentioning

confidence: 99%

“…23,24 Further deposition details of β-Ga 2 O 3 could be found in previous work. 23 Following, a 30 nm thick perovskite oxides (BaTiO 3 , SrTiO 3 , Ba 0.5 Sr 0.5 TiO 3 (named as BSTO)) were then deposited on β-Ga 2 O 3 by RF PVD (Kurt J Lesker-PVD75) in O 2 ambience with a flow rate of 20 sccm. A RF plasma power of 70 W and a chamber pressure of 10 mTorr were maintained during deposition.…”

Section: Methodsmentioning

confidence: 99%

See 4 more Smart Citations

Band Alignment of β-Ga₂O₃ with BaTiO₃, SrTiO₃, and Related Composites

Zhang,

Chen,

Jia

et al. 2023

ECS J. Solid State Sci. Technol.

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Integrating perovskite oxides BaTiO3 (BTO), SrTiO3(STO) with β-Ga2O3 is of great interest for developing β-Ga2O3 power devices due to its promotion for improving uniformity in the electric field profile and breakdown characteristics. In this work, β-Ga2O3/BaTiO3 (BTO), β-Ga2O3/SrTiO3 (STO), β-Ga2O3/Ba0.5Sr0.5TiO3 (BSTO) heterojunction were epitaxially grown on sapphire substrates by low-pressure chemical vapor deposition and radio frequency physical vapor deposition. The energy band alignment of β-Ga2O3/BaTiO3, β-Ga2O3/SrTiO3, β-Ga2O3/Ba0.5Sr0.5TiO3 (BSTO) heterojunction have been analyzed by X-ray photoemission spectroscopy and UV–visible transmittance spectrum. The conduction band offsets (∆Ec) of β-Ga2O3/BTO, β-Ga2O3/STO, β-Ga2O3/BSTO is found to be 0.32±0.05, 1.15±0.05, 0.78±0.05 eV, respectively; and the valence band offsets (∆Ev) of these heterojunction is 0.76±0.05 eV, 0.55±0.05 eV, and 0.73±0.05 eV, respectively. Our results indicate that type-I band alignment respectively form at these heterojunction, in which the valence and conduction bands of β-Ga2O3 are concomitantly higher than those of BTO, STO, and BSTO. The accurate determination of ∆Ec and ∆Ev is important for the design of β-Ga2O3/ferroelectric heterojunction multifunctional devices.

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Section: Resultsmentioning

confidence: 87%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Band Alignment of β-Ga₂O₃ with BaTiO₃, SrTiO₃, and Related Composites

Zhang,

Chen,

Jia

et al. 2023

ECS J. Solid State Sci. Technol.

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Revealing the influence of aerosol particle state on the high-quality α-Ga2O3 single crystal thin film growth by Mist CVD epitaxy

Fan,

Xiao,

Qin

et al. 2024

Materials Today Communications

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Thermodynamics of Ga₂O₃ Heteroepitaxy and Material Growth Via Metal Organic Chemical Vapor Deposition

Sanyal,

Nandi,

Cherns

et al. 2024

ACS Appl. Electron. Mater.

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Heteroepitaxy of gallium oxide (Ga 2 O 3 ) is gaining popularity to address the absence of p-type doping, limited thermal conductivity of Ga 2 O 3 epilayers, and toward realizing high-quality p-n heterojunction. During the growth of β-Ga 2 O 3 on 4H-SiC (0001) substrates using metal−organic chemical vapor deposition, we observed formation of incomplete, misoriented particles when the layer was grown at a temperature between 650 °C and 750 °C. We propose a thermodynamic model for Ga 2 O 3 heteroepitaxy on foreign substrates which shows that the energy cost of growing β-Ga 2 O 3 on 4H-SiC is slightly lower as compared to sapphire substrates, suggesting similar high-temperature growth as sapphire, typically in the range of 850 °C−950 °C, that can be used for the growth of β-Ga 2 O 3 on SiC. A two-step modified growth method was developed where the nucleation layer was grown at 750 °C followed by a buffer layer grown at various temperatures from 920 °C to 950 °C. 2θ−ω scan of X-ray diffraction (XRD) and transmission electron microscope images confirm the β-polymorph of Ga 2 O 3 with dominant peaks in the (−201) direction. The buffer layer grown at 950 °C using a "ramp-growth" technique exhibits root-mean-square surface roughness of 3 nm and full width of half maxima of XRD rocking curve as low as 0.79°, comparable to the most mature β-Ga 2 O 3 heteroepitaxy on sapphire, as predicted by the thermodynamic model. Finally, the interface energy of an average Ga 2 O 3 island grown on 4H-SiC is calculated to be 0.2 J/m 2 from the cross-section scanning transmission electron microscope image, following the Wulff-Kaishew theorem of the equilibrium island shape.

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Step flow growth of β-Ga2O3 films on off-axis 4H-SiC substrates by LPCVD

Cited by 10 publications

References 48 publications

Band Alignment of β-Ga₂O₃ with BaTiO₃, SrTiO₃, and Related Composites

Band Alignment of β-Ga₂O₃ with BaTiO₃, SrTiO₃, and Related Composites

Revealing the influence of aerosol particle state on the high-quality α-Ga2O3 single crystal thin film growth by Mist CVD epitaxy

Thermodynamics of Ga₂O₃ Heteroepitaxy and Material Growth Via Metal Organic Chemical Vapor Deposition

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Step flow growth of β-Ga2O3 films on off-axis 4H-SiC substrates by LPCVD

Cited by 10 publications

References 48 publications

Band Alignment of β-Ga2O3 with BaTiO3, SrTiO3, and Related Composites

Band Alignment of β-Ga2O3 with BaTiO3, SrTiO3, and Related Composites

Revealing the influence of aerosol particle state on the high-quality α-Ga2O3 single crystal thin film growth by Mist CVD epitaxy

Thermodynamics of Ga2O3 Heteroepitaxy and Material Growth Via Metal Organic Chemical Vapor Deposition

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Product

Resources

About

Band Alignment of β-Ga₂O₃ with BaTiO₃, SrTiO₃, and Related Composites

Band Alignment of β-Ga₂O₃ with BaTiO₃, SrTiO₃, and Related Composites

Thermodynamics of Ga₂O₃ Heteroepitaxy and Material Growth Via Metal Organic Chemical Vapor Deposition