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J. Semicond. > 2022, Volume 43 > Issue 9 > 092801

ARTICLES

Growth and characterization of β-Ga2O3 thin films grown on off-angled Al2O3 substrates by metal-organic chemical vapor deposition

Yabao Zhang1, 2, Jun Zheng1, 2, , Peipei Ma1, 2, Xueyi Zheng1, 3, Zhi Liu1, 2, Yuhua Zuo1, 2, Chuanbo Li3 and Buwen Cheng1, 2

+ Author Affiliations

 Corresponding author: Jun Zheng, zhengjun@semi.ac.cn

DOI: 10.1088/1674-4926/43/9/092801

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Abstract: Beta-gallium oxide (β-Ga2O3) thin films were deposited on c-plane (0001) sapphire substrates with different mis-cut angles along <11ˉ20> by metal-organic chemical vapor deposition (MOCVD). The structural properties and surface morphology of as-grown β-Ga2O3 thin films were investigated in detail. It was found that by using thin buffer layer and mis-cut substrate technology, the full width at half maximum (FWHM) of the (ˉ201) diffraction peak of the β-Ga2O3 film is decreased from 2° on c-plane (0001) Al2O3 substrate to 0.64° on an 8° off-angled c-plane (0001) Al2O3 substrate. The surface root-mean-square (RMS) roughness can also be improved greatly and the value is 1.27 nm for 8° off-angled c-plane (0001) Al2O3 substrate. Room temperature photoluminescence (PL) was observed, which was attributed to the self-trapped excitons formed by oxygen and gallium vacancies in the film. The ultraviolet–blue PL intensity related with oxygen and gallium vacancies is decreased with the increasing mis-cut angle, which is in agreement with the improved crystal quality measured by high resolution X-ray diffraction (HR-XRD). The present results provide a route for growing high quality β-Ga2O3 film on Al2O3 substrate.

Key words: β-Ga2O3heteroepitaxymis-cut Al2O3 substratesMOCVD

In recent years, Ga2O3 has gained considerable attention in transparent electrodes, solar-blind ultraviolet detectors, flame sensors and power devices[1-4] thanks to its ultrawide bandgap (4.5–4.9 eV)[5] and high critical breakdown field (8 MV/cm)[6]. Monoclinic crystal β-Ga2O3 has the highest thermal stability among the five phases of gallium oxide[7], and its Baliga's figure of merit (BFOM) is 3.8 and 10.14 times that of the third-generation semiconductors GaN and 4H-SiC, respectively[8]. Although homogeneous substrates are the ideal choice for growing β-Ga2O3 films, the preparation process for large size gallium oxide wafer is immature and its cost is still expensive when compared with Al2O3 substrates. Moreover, the thermal conductivity of gallium oxide is relatively poor, with values of 15.4%, 4.7% and 1.2% for silicon, 4H-SiC and diamond, respectively. Hence, the β-Ga2O3 obtained by heteroepitaxy is important for devices that generate amount of heat during operation.

There are several reports about the growth of high-quality Ga2O3 on foreign substrates[9]. Ma et al. tried to grow Ga2O3 on substrates such as SrTiO3(100)[10], epi-GaN/sapphire (0001)[11], MgO(111)[12] and MgAl6O10[13] by using MOCVD. However, these thin films were obtained by heteroepitaxy and have multiple crystal domains, which will affect the transport properties of carriers[14]. Among the different substrates, sapphire substrates are widely studied due to their low cost and smaller lattice mismatch with Ga2O3. Substantial effort has been devoted to grow high-quality Ga2O3 single crystals on sapphire substrates[15-20]. However, β-Ga2O3 and sapphire belong to different crystal phases, and multiple crystal domains will appear because of random nucleation during growth. Using sapphire substrates with off-axis angle, it was shown that the crystallinity of epitaxial β-Ga2O3 films can be improved by controlling the crystal domains. Oshima et al. have grown Ga2O3 on off-axis substrates by HVPE and found that the (310) oriented domains disappeared when off-axis angles beyond 3°[21]. It was also found that the off-angled sapphire substrates can change the growth mode of β-Ga2O3 films from six-fold in-plane rotational domain growth to single quadrilateral-domains growth[22].

In this paper, we report β-Ga2O3 epitaxial layers on Al2O3 substrates with different off-axis angles. The structural properties of β-Ga2O3 were studied, and it was found that the surface topography of β-Ga2O3 films can be greatly improved by using a buffer layer and off-angled sapphire substrates. The ultraviolet to blue light emission related with oxygen and gallium vacancies was observed and the PL mechanism was investigated.

Crystal β-Ga2O3 thin films were grown on c-plane Al2O3 substrates (Two-inch, single polished) with different off-angles (0°, 4°, 6° and 8°, corresponding to sample Nos. S0-S3) by using MOCVD (Aixtron Ltd) under the same conditions. For comparison, a Ga2O3 film (No. S0*) was also deposited without a buffer layer. Trimethylgallium (TMGa, 6N), which was stored in a stainless-steel bubbler maintained at 5 °C, and O2 (purity, 5N) were used as precursors for gallium and oxygen, respectively. High-purity argon (Ar, 5N) was applied as the carrier gas to deliver TMGa vapor to the reactor chamber by passing through the TMGa bubbler. Prior to growing β-Ga2O3 thin films at 960 °C with an O2/TMGa source flow about 2000 sccm/30 sccm (standard cubic centimeter per minute), a 10 nm thick Ga2O3 buffer layer was deposited at 800 °C with an O2/TMGa source flow about 1000 sccm/5 sccm. During the growth process, an excess oxygen source was used to avoid the formation of a large number of oxygen vacancies in the crystal. Finally, the metal organic source and oxygen cracking efficiency reached 9.5% and 0.7‰, respectively. The chamber pressure was maintained at 100 mbar during the entire growth process.

The as-grown film thickness was approximately 300 nm with the growth rate about 0.7 μm/h. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to characterize the surface morphology of the samples. HR-XRD and high-resolution transmission electron microscopy (HR-TEM) were carried out to characterize the crystal phase and quality. The room temperature photoluminescence (PL) was measured by using a 213 nm laser as excited source. The PL signal was guided into a monochromator and detected by photomultiplier.

The crystal quality of the gallium oxide thin films grown on sapphire substrates was characterized by HR-XRD in the ω–2θ configuration, as shown in Fig. 1. For the film grown on sapphire substrate (S0*) without a buffer layer, the XRD spectrum shows totally different pattern. By comparing to PDF #06-0529, the appearance of a diffraction peak centered at 46.43° may belong to the δ-Ga2O3 domains. Zhuo et al. reported that when Ga2O3 was first deposited on Al2O3 substrates, there were nuclei of various phases[17]. This result also proves that the existence of the buffer layer promoted the growth of β-Ga2O3. However, for the films grown on Al2O3 substrates with a buffer layer, three sharp diffraction peaks located at 18.45°, 38.29° and 58.95° are observed, which belong to the (ˉ201), (ˉ402) and (ˉ603) planes of β-Ga2O3 (compared to JCPDS No. 43-1012). These results show that the obtained gallium oxide films with a buffer layer are pure β-Ga2O3 without any other gallium oxide phase. The preferential crystal growth direction is (ˉ201) because the arrangement of oxygen atoms in the β-Ga2O3 (ˉ201) plane is equivalent to sapphire (0001)[15]. Fig. 2 shows the XRD rocking curves at the (ˉ201) diffraction peak of the four samples. With the increasing substrates off-axis angles, the XRD peak intensity increases and the full width at half maximum (FWHM) of the (ˉ201) diffraction peak is decreased, reaching 0.64° for the film deposited on an 8° off-angled substrate. To illustrate the effect of the buffer layer clearly, β-Ga2O3 film without a buffer layer was also grown on the Al2O3 substrate with 8° off-axis angles toward <11ˉ20>. Very weak X-ray diffraction peak belong to (ˉ201), (ˉ402) and (ˉ603) was observed and the RMS value was 7.5 nm (the RMS value for the film with a buffer is 1.27 nm), from the AFM measurement. (Figures not shown here.) This indicates that the surface topography of β-Ga2O3 films grown on off-angled Al2O3 substrates can be improved by introducing a buffer layer prior to thick film growth.

Fig. 1.  (Color online) XRD patterns of β-Ga2O3 films deposited on c-plane Al2O3 substrates with different off-axis angles toward <11ˉ20>.
Fig. 2.  (Color online) (a) XRD rocking curves of the (ˉ201) diffraction peaks of β-Ga2O3 films deposited on c-plane Al2O3 substrates with different off-axis angles toward <11ˉ20>, (b) FWHM as a function of off-axis angles of Al2O3 substrates.

To explain the role of buffer layer and mis-cut substrate angle, HR-TEM experiments were carried out. As shown in Fig. 3(a), the step is clearly visible along the <11ˉ20> direction of the Al2O3 substrate. The (ˉ201) plane distance of the epitaxial layer is calculated to be 0.466 nm by performing a Fourier transform on the region selected by the yellow dashed box in Fig. 3(b). As the thickness of the epitaxial layer increases, the atoms are arranged more orderly and most dislocations are successfully constrained in the thin buffer layer. Figs. 3(c) and 3(d) show the SAED patterns of buffer layer near and away the Ga2O3 films/Al2O3 interface, respectively. The SAED pattern consists of multiple sets of diffraction spots near the interface and became more regular in region A. This indicates that there were other phases of Ga2O3 in the initial growth period and the epitaxial layer gradually became pure β-Ga2O3 as the film continued to grow. Thus, the great improvement in crystal quality is likely to happen because mis-cut sapphire can inhibit the appearance of the crystal domain by the strong in-plane orientation enhancement[23] and the buffer layer can accommodate most defects.

Fig. 3.  Cross-sectional TEM of the film deposited on an 8° off-axis sapphire substrate with a thickness of 300 nm. (a) Image of the whole film. (b) HRTEM micrograph of the interface. (c) Selected area electron diffraction (SAED) obtained by Fourier transform of area B. (d) Selected area electron diffraction (SAED) obtained by Fourier transform of area A.

Fig. 4 shows the AFM image of β-Ga2O3 films deposited on different off-axis Al2O3 substrates. The measured surface RMS roughness values of samples S0, S1, S2 and S3 are 6, 2.58, 3.55 and 1.27 nm, respectively. The film deposited on an 8° off-axis Al2O3 substrate has the lowest RMS roughness. The RMS value in this work is much lower than the reported values grown on off-angled Al2O3 substrates[24]. There are many tiny domains on the surface of the as-grown sample, indicating that the growth changes from a two-dimensional plane growth to a three-dimensional island-like growth pattern. To further reveal the low RMS values of those grown on off-axis sapphire substrates, the surface morphology of β-Ga2O3 films was also characterized by SEM, as demonstrated in Fig. 5. The surface domain of the films deposited on mis-cut sapphire substrates seems more closely due to step-flow growth[25] and the film surface shows a corrugated shape, which is the phenomenon of step bunching[26].

Fig. 4.  (Color online) 10 × 10 μm2 AFM patterns of β-Ga2O3 films deposited on (a) 0°, (b) 4°, (c) 6° and (d) 8° off-axis Al2O3 substrates. All films were annealed in-situ for 10 min under an oxygen atmosphere.
Fig. 5.  SEM of β-Ga2O3 thin films on Al2O3 substrates with (a) 0°, (b) 4°, (c) 6°, and (d) 8° off-angles toward <11ˉ20>.

PL spectrum is an effective method to investigate the defects of as-grown β-Ga2O3 thin films. Fig. 6 shows the room temperature (297 K) PL spectra of β-Ga2O3 thin films excited by a 213 nm laser. Compared with the samples grown on the off-axis substrates (S1, S2 and S3), the luminescence of the sample S0 grown on the normal Al2O3 substrate is significantly weaker, which is due to the large number of non-radiative recombination centers generated by the crystal domain interface. The PL spectra have a broad emission band from ultraviolet to blue. The broad emission can be divided into two emission peaks near 365 and 410 nm, as shown in Figs. 6(b)–6(d). Varley et al. reported that self-trapped holes (STHs) were widespread in β-Ga2O3 and localized mainly on a single O atom in the lattice with the shape characteristic of an O 2p orbital[27]. The 365 nm peak is the process of radiative recombination between STHs and electrons to form STEs. This process has a strong electron-phonon coupling effect and local lattice distortion can cause the spectral broadening. The blue emission is overlapped at the UV band tail, which has been widely reported and is suggested to be related to donor-acceptor-pair recombination between VO donor and VGa or VGa–VO complex acceptors[27, 28]. The radiative recombination luminescence from the conduction band and valence band of β-Ga2O3 is not observed in all samples, which is likely to be due to the fast non-radiative transition to the self-trapped energy level. As shown in Fig. 6(a), the PL intensity is the strongest for the S1 sample and decreases with increasing substrate off-axis angles. Thus, the decrease in PL intensity indicates that the density of O and Ga vacancies are reduced. This is in accordance with the improved crystal quality from the XRD measurement.

Fig. 6.  (Color online) (a) Room temperature PL spectra of all films grown on off-angled Al2O3 substrates. The broad emission band from ultraviolet to blue of the β-Ga2O3 film deposited on (b) 4°, (c) 6°, and (d) 8° can be divided into two emission peaks near 365 and 410 nm.

In summary, β-Ga2O3 thin films were successfully grown on c-plane mis-cut Al2O3 substrates. Our results showed that the quality of the β-Ga2O3 thin films was improved by step-flow growth, and the FWHM of the (ˉ201) plane of the film deposited on an 8° off-angled substrate was 0.64°. It was revealed that the dislocations were mainly blocked by the buffer as observed by TEM measurement. The surface RMS roughness can also be reduced for the β-Ga2O3 films deposited on off-axis Al2O3 substrates, reaching about 1.27 nm. The β-Ga2O3 film had broad light emission from ultraviolet to blue, which was attributed to the oxygen vacancies and gallium vacancies in the films. This vacancy related PL intensity was decreased with increasing off-angle, showing the improved crystalline quality, which was consistent with the HR-XRD results. These findings are helpful for the fabrication of high performance β-Ga2O3 devices based on Al2O3 substrate in near future.

This work was supported in part by the National Key Research and Development Program of China (Grant No. 2018YFB2200500), the National Natural Science Foundation (Grant Nos. 62050073, 62090054, 61975196).



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Qian C, Sun J, Zhang L, et al. Crystal-domain orientation and boundary in highly ordered organic semiconductor thin film. J Phys Chem C, 2015, 119, 14965 doi: 10.1021/acs.jpcc.5b03727
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Nakagomi S, Kokubun Y. Crystal orientation of β-Ga2O3 thin films formed on c-plane and a-plane sapphire substrate. J Cryst Growth, 2012, 349, 12 doi: 10.1016/j.jcrysgro.2012.04.006
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Oshima Y, Vίllora E G, Shimamura K. Quasi-heteroepitaxial growth of β-Ga2O3 on off-angled sapphire (0001) substrates by halide vapor phase epitaxy. J Cryst Growth, 2015, 410, 53 doi: 10.1016/j.jcrysgro.2014.10.038
[22]
Xu W L, Shi J C, Li Y W, et al. Study of β-Ga2O3 films hetero-epitaxially grown on off-angled sapphire substrates by halide vapor phase epitaxy. Mater Lett, 2021, 289, 129411 doi: 10.1016/j.matlet.2021.129411
[23]
Rafique S, Han L, Neal A T, et al. Towards high-mobility heteroepitaxial β-Ga2O3 on sapphire–dependence on the substrate off-axis angle. Phys Status Solidi A, 2018, 215, 1700467 doi: 10.1002/pssa.201700467
[24]
Zhang T, Hu Z G, Li Y F, et al. Investigation on the β-Ga2O3 deposited on off-angled sapphire (0001) substrates. J Lumin, 2021, 233, 117928 doi: 10.1016/j.jlumin.2021.117928
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[26]
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[27]
Varley J B, Janotti A, Franchini C, et al. Role of self-trapping in luminescence andp-type conductivity of wide-band-gap oxides. Phys Rev B, 2012, 85, 081109 doi: 10.1103/PhysRevB.85.081109
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Fig. 1.  (Color online) XRD patterns of β-Ga2O3 films deposited on c-plane Al2O3 substrates with different off-axis angles toward <11ˉ20>.

Fig. 2.  (Color online) (a) XRD rocking curves of the (ˉ201) diffraction peaks of β-Ga2O3 films deposited on c-plane Al2O3 substrates with different off-axis angles toward <11ˉ20>, (b) FWHM as a function of off-axis angles of Al2O3 substrates.

Fig. 3.  Cross-sectional TEM of the film deposited on an 8° off-axis sapphire substrate with a thickness of 300 nm. (a) Image of the whole film. (b) HRTEM micrograph of the interface. (c) Selected area electron diffraction (SAED) obtained by Fourier transform of area B. (d) Selected area electron diffraction (SAED) obtained by Fourier transform of area A.

Fig. 4.  (Color online) 10 × 10 μm2 AFM patterns of β-Ga2O3 films deposited on (a) 0°, (b) 4°, (c) 6° and (d) 8° off-axis Al2O3 substrates. All films were annealed in-situ for 10 min under an oxygen atmosphere.

Fig. 5.  SEM of β-Ga2O3 thin films on Al2O3 substrates with (a) 0°, (b) 4°, (c) 6°, and (d) 8° off-angles toward <11ˉ20>.

Fig. 6.  (Color online) (a) Room temperature PL spectra of all films grown on off-angled Al2O3 substrates. The broad emission band from ultraviolet to blue of the β-Ga2O3 film deposited on (b) 4°, (c) 6°, and (d) 8° can be divided into two emission peaks near 365 and 410 nm.

[1]
Jeong Y J, Yang J Y, Lee C H, et al. Fluorine-based plasma treatment for hetero-epitaxial β-Ga2O3 MOSFETs. Appl Surf Sci, 2021, 558, 149936 doi: 10.1016/j.apsusc.2021.149936
[2]
Jubu P R, Yam F K. Development and characterization of MSM UV photodetector based on gallium oxide nanostructures. Sens Actuator A, 2020, 312, 112141 doi: 10.1016/j.sna.2020.112141
[3]
Lv Y J, Zhou X Y, Long S B, et al. Enhancement-mode β-Ga2O3 metal-oxide-semiconductor field-effect transistor with high breakdown voltage over 3000 V realized by oxygen annealing. Phys Status Solidi RRL, 2020, 14, 1900586 doi: 10.1002/pssr.201900586
[4]
Dong H, Xue H W, He Q M, et al. Progress of power field effect transistor based on ultra-wide bandgap Ga2O3 semiconductor material. J Semicond, 2019, 40, 011802 doi: 10.1088/1674-4926/40/1/011802
[5]
Tippins H H. Optical absorption and photoconductivity in the band edge of β-Ga2O3. Phys Rev, 1965, 140, A316 doi: 10.1103/PhysRev.140.A316
[6]
Ueda N, Hosono H, Waseda R, et al. Anisotropy of electrical and optical properties in β-Ga2O3 single crystals. Appl Phys Lett, 1997, 71, 933 doi: 10.1063/1.119693
[7]
Kohn J A, Broder J D. Characterization of β-Ga2O3 and its alumina isomorph, θ-Al2O3. Am Mineral, 1957, 42, 398
[8]
Stepanov S I, Nikolaev V I, Bougrov V E, et al. Gallium oxide: Properties and applications - A review. Rev Adv Mater Sci, 2016, 44, 63
[9]
Pearton S J, Yang J C, Cary P H, et al. A review of Ga2O3 materials, processing, and devices. Appl Phys Rev, 2018, 5, 011301 doi: 10.1063/1.5006941
[10]
Wang D, He L N, Le Y, et al. Characterization of single crystal β-Ga2O3 films grown on SrTiO3 (100) substrates by MOCVD. Ceram Int, 2020, 46, 4568 doi: 10.1016/j.ceramint.2019.10.185
[11]
Cao Q, He L N, Xiao H D, et al. β-Ga2O3 epitaxial films deposited on epi-GaN/sapphire (0001) substrates by MOCVD. Mater Sci Semicond Process, 2018, 77, 58 doi: 10.1016/j.mssp.2018.01.010
[12]
Mi W, Ma J, Luan C N, et al. Characterization of β-Ga2O3 epitaxial films grown on MgO (111) substrates by metal-organic chemical vapor deposition. Mater Lett, 2012, 87, 109 doi: 10.1016/j.matlet.2012.07.106
[13]
Mi W, Luan C N, Li Z, et al. Ultraviolet-green photoluminescence of β-Ga2O3 films deposited on MgAl6O10 (100) substrate. Opt Mater, 2013, 35, 2624 doi: 10.1016/j.optmat.2013.07.030
[14]
Qian C, Sun J, Zhang L, et al. Crystal-domain orientation and boundary in highly ordered organic semiconductor thin film. J Phys Chem C, 2015, 119, 14965 doi: 10.1021/acs.jpcc.5b03727
[15]
Nakagomi S, Kokubun Y. Crystal orientation of β-Ga2O3 thin films formed on c-plane and a-plane sapphire substrate. J Cryst Growth, 2012, 349, 12 doi: 10.1016/j.jcrysgro.2012.04.006
[16]
Boschi F, Bosi M, Berzina T, et al. Hetero-epitaxy of ε-Ga2O3 layers by MOCVD and ALD. J Cryst Growth, 2016, 443, 25 doi: 10.1016/j.jcrysgro.2016.03.013
[17]
Zhuo Y, Chen Z M, Tu W B, et al. β-Ga2O3 versus ε-Ga2O3: Control of the crystal phase composition of gallium oxide thin film prepared by metal-organic chemical vapor deposition. Appl Surf Sci, 2017, 420, 802 doi: 10.1016/j.apsusc.2017.05.241
[18]
Hu D Q, Wang Y, Zhuang S W, et al. Surface morphology evolution and optoelectronic properties of heteroepitaxial Si-doped β-Ga2O3 thin films grown by metal-organic chemical vapor deposition. Ceram Int, 2018, 44, 3122 doi: 10.1016/j.ceramint.2017.11.079
[19]
Wu J W, Mi W, Yang Z C, et al. Influence of annealing on the structural and optical properties of gallium oxide films deposited on c-sapphire substrate. Vacuum, 2019, 167, 6 doi: 10.1016/j.vacuum.2019.05.034
[20]
Wei J Q, Kim K, Liu F, et al. β-Ga2O3 thin film grown on sapphire substrate by plasma-assisted molecular beam epitaxy. J Semicond, 2019, 40, 012802 doi: 10.1088/1674-4926/40/1/012802
[21]
Oshima Y, Vίllora E G, Shimamura K. Quasi-heteroepitaxial growth of β-Ga2O3 on off-angled sapphire (0001) substrates by halide vapor phase epitaxy. J Cryst Growth, 2015, 410, 53 doi: 10.1016/j.jcrysgro.2014.10.038
[22]
Xu W L, Shi J C, Li Y W, et al. Study of β-Ga2O3 films hetero-epitaxially grown on off-angled sapphire substrates by halide vapor phase epitaxy. Mater Lett, 2021, 289, 129411 doi: 10.1016/j.matlet.2021.129411
[23]
Rafique S, Han L, Neal A T, et al. Towards high-mobility heteroepitaxial β-Ga2O3 on sapphire–dependence on the substrate off-axis angle. Phys Status Solidi A, 2018, 215, 1700467 doi: 10.1002/pssa.201700467
[24]
Zhang T, Hu Z G, Li Y F, et al. Investigation on the β-Ga2O3 deposited on off-angled sapphire (0001) substrates. J Lumin, 2021, 233, 117928 doi: 10.1016/j.jlumin.2021.117928
[25]
Bryan I, Bryan Z, Mita S, et al. Surface kinetics in AlN growth: A universal model for the control of surface morphology in III-nitrides. J Cryst Growth, 2016, 438, 81 doi: 10.1016/j.jcrysgro.2015.12.022
[26]
Xie M H, Cheung S H, Zheng L X, et al. Step bunching of vicinal GaN(0001) surfaces during molecular beam epitaxy. Phys Rev B, 2000, 61, 9983 doi: 10.1103/PhysRevB.61.9983
[27]
Varley J B, Janotti A, Franchini C, et al. Role of self-trapping in luminescence andp-type conductivity of wide-band-gap oxides. Phys Rev B, 2012, 85, 081109 doi: 10.1103/PhysRevB.85.081109
[28]
Ho C H, Tseng C Y, Tien L C. Thermoreflectance characterization of beta-Ga2O3 thin-film nanostrips. Opt Express, 2010, 18, 16360 doi: 10.1364/OE.18.016360
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    Yabao Zhang, Jun Zheng, Peipei Ma, Xueyi Zheng, Zhi Liu, Yuhua Zuo, Chuanbo Li, Buwen Cheng. Growth and characterization of β-Ga2O3 thin films grown on off-angled Al2O3 substrates by metal-organic chemical vapor deposition[J]. Journal of Semiconductors, 2022, 43(9): 092801. doi: 10.1088/1674-4926/43/9/092801
    Y B Zhang, J Zheng, P P Ma, X Y Zheng, Z Liu, Y H Zuo, C B Li, B W Cheng. Growth and characterization of β-Ga2O3 thin films grown on off-angled Al2O3 substrates by metal-organic chemical vapor deposition[J]. J. Semicond, 2022, 43(9): 092801. doi: 10.1088/1674-4926/43/9/092801
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    History

    Received: 13 January 2022 Revised: 08 April 2022 Online: Accepted Manuscript: 15 May 2022Uncorrected proof: 18 May 2022Published: 02 September 2022

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      Yabao Zhang, Jun Zheng, Peipei Ma, Xueyi Zheng, Zhi Liu, Yuhua Zuo, Chuanbo Li, Buwen Cheng. Growth and characterization of β-Ga2O3 thin films grown on off-angled Al2O3 substrates by metal-organic chemical vapor deposition[J]. Journal of Semiconductors, 2022, 43(9): 092801. doi: 10.1088/1674-4926/43/9/092801 ****Y B Zhang, J Zheng, P P Ma, X Y Zheng, Z Liu, Y H Zuo, C B Li, B W Cheng. Growth and characterization of β-Ga2O3 thin films grown on off-angled Al2O3 substrates by metal-organic chemical vapor deposition[J]. J. Semicond, 2022, 43(9): 092801. doi: 10.1088/1674-4926/43/9/092801
      Citation:
      Yabao Zhang, Jun Zheng, Peipei Ma, Xueyi Zheng, Zhi Liu, Yuhua Zuo, Chuanbo Li, Buwen Cheng. Growth and characterization of β-Ga2O3 thin films grown on off-angled Al2O3 substrates by metal-organic chemical vapor deposition[J]. Journal of Semiconductors, 2022, 43(9): 092801. doi: 10.1088/1674-4926/43/9/092801 ****
      Y B Zhang, J Zheng, P P Ma, X Y Zheng, Z Liu, Y H Zuo, C B Li, B W Cheng. Growth and characterization of β-Ga2O3 thin films grown on off-angled Al2O3 substrates by metal-organic chemical vapor deposition[J]. J. Semicond, 2022, 43(9): 092801. doi: 10.1088/1674-4926/43/9/092801

      Growth and characterization of β-Ga2O3 thin films grown on off-angled Al2O3 substrates by metal-organic chemical vapor deposition

      DOI: 10.1088/1674-4926/43/9/092801
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      • Yabao Zhang:received his BSci degree from Jilin University, China in 2019. He is currently a master's student at the Institute of Semiconductors, Chinese Academy of Sciences. His research interest is the epitaxial growth mechanism of gallium oxide
      • Jun Zheng:received the BSci degree from Beijing Institute of Technology, China in 2006 and PhD degree in physical electronics from Graduated University of Chinese Academy of Sciences, China in 2011. He is now an associate researcher in Institute of Semiconductors, Chinese Academy of Sciences, China. His research interest is silicon photonics and gallium oxide devices
      • Corresponding author: zhengjun@semi.ac.cn
      • Received Date: 2022-01-13
      • Revised Date: 2022-04-08
      • Available Online: 2022-05-15

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