Effects of Sapphire Substrate Preparation on ZnO Epitaxial Growth by Atmospheric-Pressure Metal Organic Chemical Vapor Deposition

Akiyama, Shutetsu; Minegishi, Kazunori; Tanaka, Tooru; Ogawa, Hiroshi; Kasuga, Masanobu

doi:10.1143/jjap.46.342

Cited by 9 publications

(11 citation statements)

References 33 publications

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“…This domain aligns the [100] directions for both ZnO and Al 2 O 3 and has been observed in other ALD studies . For ZnO deposition at higher temperatures, other rotational domains have been observed, mainly one rotated around the [001] axis by ±30°, with respect to this one. − The coincidence superstructure for T 1 shown in Figure a exhibits 6-fold symmetry. Indeed, the open white squares in the (100) and (101)-pole figures (Figures d and f) are consistent with this symmetry.…”

Section: Discussionsupporting

confidence: 79%

“…These ZnO grains fulfill the following epitaxial relationship: (001) ZnO∥(001) Al 2 O 3 and [100] ZnO∥[100] Al 2 O 3 (Figure a). While others have also found (001) domains with an in-plane rotation of 30°, with respect to these, − a significant population of such domains were not observed here, since these would lead to additional (unobserved) reflections in the (101) pole figure.…”

Section: Resultsmentioning

confidence: 48%

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Evolution of Crystal Structure During the Initial Stages of ZnO Atomic Layer Deposition

et al. 2016

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International audienceA complementary suite of in situ synchrotron X-ray techniques is used to investigate both structural and chemical evolution during ZnO growth by atomic layer deposition. Focusing on the first 10 cycles of growth, we observe that the structure formed during the coalescence stage largely determines the overall microstructure of the film. Furthermore, by comparing ZnO growth on silicon with a native oxide with that on Al2O3(001), we find that even with lattice-mismatched substrates and low deposition temperatures, the crystalline texture of the films is dependent strongly on the nature of the interfacial bonds

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Section: Discussionsupporting

confidence: 79%

Section: Resultsmentioning

confidence: 48%

Evolution of Crystal Structure During the Initial Stages of ZnO Atomic Layer Deposition

et al. 2016

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“…For epitaxial growth of ZnO layers on sapphire substrate, rotational domains are a frequently reported problem. − Therefore, we performed EBSD measurements on the sample grown for 300 min, shown in Figure . We were scanning an area of about 400 × 300 μm 2 in order to get a statistically significant result.…”

Section: Resultsmentioning

confidence: 99%

High-Quality ZnO Layers Grown by CVD on Sapphire Substrates with an AlN Nucleation Layer

Müller

Huber

Töws

et al. 2020

Crystal Growth & Design

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The growth of single-crystalline high-quality zinc oxide (ZnO) layers by a methane (CH 4 )-based chemical vapor deposition (CVD) growth process on sapphire substrates with an aluminum nitride (AlN) nucleation layer was investigated. We achieved monocrystalline ZnO layers free of rotational domains, which show in high-resolution X-ray diffraction (HRXRD) measurements a very narrow (∼110 arcsec) full width at halfmaximum (fwhm) in ω scans for the ZnO (0002) reflection. The influence of growth time and layer thickness on crystal properties such as surface roughness, dislocation density, and optical properties was investigated. We find low edge and screw dislocation densities of around 6.4 × 10 8 and 2.1 × 10 7 cm −2 , respectively. In low-temperature photoluminescence (PL) spectra the fwhm of the donor-bound exciton emission drops to about 170 μeV for increasing layer thickness. Moreover, these layers have a smooth surface with a surface roughness RMS value of 4 nm and a very low donor concentration of about 1.7 × 10 15 cm −3 . We also studied the influence of substrate miscut on crystal growth properties and found no significant influence. The results prove the high potential of methane-based chemical vapor deposition for the production of high-quality ZnO layers.

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“…As pointed out above, the epitaxial in-plane relationship between ZnO and Al 2 O 3 depends on the relative alignment of ZnO to the O-sublattice of Al 2 O 3 . In recent publications [80,81], it has been demonstrated that a substrate annealing step at elevated temperatures prior to deposition leads to an oxygen-terminated surface, improving both the quality of the substrate and the epitaxial ZnO thin film. We studied this effect and found a significant improvement of the structural quality after annealing the substrate at T sub = 850 • C for 1 h in a pure O 2 atmosphere of 10 −3 mbar.…”

Section: Laser Fluencementioning

confidence: 99%

Laser molecular beam epitaxy of ZnO thin films and heterostructures

Opel¹,

Geprägs²,

Althammer³

et al. 2013

J. Phys. D: Appl. Phys.

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Abstract. We report on the growth of epitaxial ZnO thin films and ZnO based heterostructures on sapphire substrates by laser molecular beam epitaxy (MBE). We first discuss some recent developments in laser-MBE such as flexible ultraviolet laser beam optics, infrared laser heating systems or the use of atomic oxygen and nitrogen sources, and describe the technical realization of our advanced laser-MBE system. Then we describe the optimization of the deposition parameters for ZnO films such as laser fluence and substrate temperature and the use of buffer layers. The detailed structural characterization by x-ray analysis and transmission electron microscopy shows that epitaxial ZnO thin films with high structural quality can be achieved, as demonstrated by a small out-of-plane and in-plane mosaic spread as well as the absence of rotational domains. We also demonstrate the heteroepitaxial growth of ZnO based multilayers as a prerequisite for spin transport experiments and the realization of spintronic devices. As an example, we show that TiN/Co/ZnO/Ni/Au multilayer stacks can be grown on (0001)-oriented sapphire with good structural quality of all layers and well defined inplane epitaxial relations.

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Effects of Sapphire Substrate Preparation on ZnO Epitaxial Growth by Atmospheric-Pressure Metal Organic Chemical Vapor Deposition

Cited by 9 publications

References 33 publications

Evolution of Crystal Structure During the Initial Stages of ZnO Atomic Layer Deposition

Evolution of Crystal Structure During the Initial Stages of ZnO Atomic Layer Deposition

High-Quality ZnO Layers Grown by CVD on Sapphire Substrates with an AlN Nucleation Layer

Laser molecular beam epitaxy of ZnO thin films and heterostructures

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