Structure dependence of ferroelectricity in high quality 
BiMnO3
 epitaxial films

The high quality thin films of high-Tc superconducting oxide are necessary for elucidating the superconducting mechanism and for device application. The recent trend in the preparation of high-Tc films has been toward “in-situ” growth of the superconducting phase at relatively low temperatures. The purpose of “in-situ” growth is to attain surface smoothness suitable for fabricating film devices but also to obtain high quality film. We present the investigation on the initial growth manner of YBCO by in-situ reflective high energy electron diffraction (RHEED) technique and on the structural and superconducting properties of the resulting ultrathin films below 100Å. The epitaxial films have been grown on (100) plane of MgO and SrTiO, heated below 650°C by activated reactive evaporation. The in-situ RHEED observation and the intensity measurement was carried out during deposition of YBCO on the substrate at 650°C. The deposition rate was 0.8Å/s. Fig. 1 shows the RHEED patterns at every stage of deposition of YBCO on MgO(100). All the patterns exhibit the sharp streaks, indicating that the film surface is atomically smooth and the growth manner is layer-by-layer.

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Twisted oxide lateral homostructures with conjunction tunability

10.21203/rs.3.rs-517146/v1 ◽

2021 ◽

Author(s):

Jan-Chi Yang ◽

Ping-Chun Wu ◽

Chia-Chun Wei ◽

Qilan Zhong ◽

Sheng-Zhu Ho ◽

...

Keyword(s):

Wide Spectrum ◽

Strain Engineering ◽

Epitaxial Films ◽

Modern Technology ◽

Specific Substrate ◽

Lattice Structures ◽

High Quality ◽

The Past ◽

Sharp Interfaces ◽

Selection Of

Abstract Epitaxial growth is of significant importance over the past decades, given it has been the key process of modern technology for delivering high-quality thin films. For conventional heteroepitaxy, the selection of proper single crystal substrates not only facilitates the integration of different materials but also fulfills interface and strain engineering upon a wide spectrum of functionalities. Nevertheless, the lattice structures, regularity and crystalline orientation are determined once a specific substrate is chosen. In this work, we reveal the growth of twisted oxide lateral homostructures with multiple conjunction degree of freedom. The twisted lateral homostructures with atomically sharp interfaces can be composed of epitaxial “blocks” with different crystalline orientations, ferroic orders and phases. We further demonstrate that this approach is universal for fabricating various complex systems. Our results establish an efficient pathway towards twisted lateral homostructures, allowing epitaxial films to be arbitrarily tailored at designated positions with unbounded in-plane conjunction tunability.

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High quality thick epitaxial films for power semiconductor devices

Microelectronics Reliability ◽

10.1016/0026-2714(87)90718-9 ◽

1987 ◽

Vol 27 (1) ◽

pp. 189-190

Keyword(s):

Semiconductor Devices ◽

Epitaxial Films ◽

High Quality ◽

Power Semiconductor ◽

Power Semiconductor Devices

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(Invited) Enabling Low Temperature and High Quality Epitaxial Films for Current and Future Nodes

ECS Meeting Abstracts ◽

10.1149/ma2018-02/31/1053 ◽

2018 ◽

Keyword(s):

Low Temperature ◽

Epitaxial Films ◽

High Quality

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The Electronic Properties of Epitaxial Calcium Fluoride-Silicon Structures

MRS Proceedings ◽

10.1557/proc-54-295 ◽

1985 ◽

Vol 54 ◽

Cited By ~ 11

Author(s):

T. P. Smith ◽

J. M. Phillips ◽

R. People ◽

J. M. Gibson ◽

L. Pfeiffer ◽

...

Keyword(s):

Electronic Properties ◽

Material Properties ◽

Calcium Fluoride ◽

Minority Carrier ◽

Electronic Devices ◽

Epitaxial Films ◽

High Quality ◽

Silicon Structures

ABSTRACTThe characterization of electronic devices using epitaxial CaF2 on Si is described. In addition, the growth and annealing techniques used to obtain high quality epitaxial films are discussed. In particular, the results of using rapid thermal annealing to improve the epitaxial quality of CaF2 films are presented in detail.The electronic and electrical properties of these structures are very promising. Epitaxial CaF2 films with breakdown fields as high as 3 × 106 V/cm and interface trap densities as low as 7 × 1010cm-2eV-1 have been fabricated. In addition, minority carrier dominated trapping has been observed at the CaF2 /Si interface. Finally, the material properties of these structures, as determined by Rutherford backscattering, channeling, and electron microscopy, are discussed and correlated with their electronic properties.

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ScAlMgO4: an Oxide Substrate for GaN Epitaxy

MRS Internet Journal of Nitride Semiconductor Research ◽

10.1557/s1092578300001733 ◽

1996 ◽

Vol 1 ◽

Cited By ~ 30

Author(s):

E. S. Hellman ◽

C. D. Brandle ◽

L. F. Schneemeyer ◽

D. Wiesmann ◽

I. Brener ◽

...

Keyword(s):

Molecular Beam ◽

Nitrogen Plasma ◽

Epitaxial Films ◽

Czochralski Growth ◽

Congruent Melting ◽

X Ray Diffraction ◽

High Quality ◽

X Ray ◽

Oxide Substrate ◽

Deposition Conditions

We report the use of ScAlMgO4 as a substrate for the epitaxial growth of wurzitic GaN. The low misfit (+1.8%) allows coherent epitaxy of GaN, as observed by RHEED. The congruent melting of ScAlMgO4 makes Czochralski growth possible, suggesting that large, high quality substrates can be realized. Boules about 17mm in diameter are reported. We have used nitrogen-plasma molecular beam epitaxy to grow GaN epitaxial films onto ScAlMgO4 substrates. Band-gap photoluminescence has been observed from some of these films, depending primarily on the deposition conditions. A 3×3 superstructure has been observed by RHEED on the GaN surfaces. Structural analysis by x-ray diffraction indicates very good in-plane alignment of the GaN films. We also report thermal expansion measurements for ScAlMgO4.

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High Quality Epitaxial Films of ZnSe and ZnSe/ZnS Strained Layer Superlattices Grown by MOCVD

MRS Proceedings ◽

10.1557/proc-242-293 ◽

1992 ◽

Vol 242 ◽

Cited By ~ 1

Author(s):

Chungdee Pong ◽

R. C. DeMattei ◽

R. S. Feigelson

Keyword(s):

Surface Morphology ◽

Rutherford Backscattering Spectrometry ◽

Epitaxial Films ◽

Process Conditions ◽

High Quality ◽

Cross Sectional ◽

Strained Layer ◽

Quantum Size ◽

Photoluminescence Studies ◽

Strained Layer Superlattices

ABSTRACTHigh quality epitaxial films of ZnSe and ZnSe/ZnS strained layer superlattices (SLS) have been grown on (100) GaAs substrates using diethylZinc, dimethylSelenide, diethylSelenide, and propyleneSulfide as reagents in both atmospheric and low pressure environment. This source combination produces the results showing the influence of process conditions, such as reagent flow ratio (fv1/f11) and substrate temperature, on the film stoichiometry, surface morphology, and crystalline quality. Low temperature photoluminescence (PL), Rutherford backscattering spectrometry (RBS), cross-sectional TEM, and x-ray diffraction have been used to characterize the films. Photoluminescence studies at 2.8 K on samples of ZnSe/ZnS strained layer superlattices; 10 periods ZnSe(1.5 nm)/ZnS(8.5 nm), have shown quantum size effect with the peak energy blue-shifted to 3.03 eV with the FWHM=73 meV. Atomic force microscopy (AFM) was applied to study surface morphology of multilayer samples.

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Growth of GaN epilayers on Si(111) substrates using multiple buffer layers

MRS Proceedings ◽

10.1557/proc-693-i3.20.1 ◽

2001 ◽

Vol 693 ◽

Cited By ~ 5

Author(s):

P.R. Hageman ◽

S. Haffouz ◽

A. Grzegorczk ◽

V. Kirilyuk ◽

P.K. Larsen

Keyword(s):

Atomic Force Microscopy ◽

Epitaxial Films ◽

Buffer Layers ◽

High Quality ◽

Nucleation Layer ◽

Force Microscopy ◽

Atomic Force ◽

Intermediate Layers ◽

Vapor Deposition Technique

AbstractWe present a study of the growth of high quality GaN films on Si(111) substrates by MetalOrganic Chemical Vapor Deposition technique. In order to improve the quality of the epitaxial films we introduced different nucleation or buffer layers and combinations of them. Our results obtained on an optimized AlN nucleation layer will serve as reference point. In order to improve the quality of the epitaxial films we introduced different combinations of nucleation and intermediate layers. The first combination consists of an optimized AlN nucleation layer followed by a 1 m-thick GaN film, on which we deposited SixNy/GaN intermediate layers. Based on the optimized AlN nucleation layer, we introduced AlGaN/GaN superlattices or AlN intermediate buffer layers. Additionally, we present results on the modification the Si(111) surface with NH3 to promote nucleation from selective GaN islands. In all experiments the total thickness of the GaN epilayers was 3 m m. X-ray diffraction, photoluminescence, Hall measurements and atomic force microscopy were used in order to elucidate the effectiveness of these growth processes. For the most successful deposition scheme, the one with the SixNy/GaN intermediate layers, the resulting GaN layers are of high quality as compared to the other methods. The donor bound exciton, which dominates the photoluminescence spectrum, showed a full width at half maximum (FWHM) of about 50 meV at room temperature and 10 meV at 4K. The FWHM of the symmetric (0002) rocking curves in w-scan is about 640 arcsec. The root-mean-square roughness, as measured by atomic force microscopy, does not exceed 10 Å.

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