Growth of ZnO Thin Films on Sapphire Substrates by ECR-Assisted MBE

1997 ◽  
Vol 474 ◽  
Author(s):  
Hee-Bog Kang ◽  
Kiyoshi Nakamura ◽  
Kazuo Ishikawa
Keyword(s):  
Sapphire Substrate ◽  
Electron Cyclotron Resonance ◽  
Rf Sputtering ◽  
Zno Films ◽  
Zno Film ◽  
Epitaxial Relationship ◽  
Rocking Curve ◽  
Sapphire Substrates ◽  
Relationship Of ◽  
Ecr Source

ABSTRACTEpitaxial ZnO films were grown on c-plane sapphire substrate at low temperature using the electron cyclotron resonance-assisted molecular beam epitaxy(ECR-assisted MBE) technique. In this method, Zn vapor provided by a Knudsen cell reacts with oxygen activated in an ECR source on the surface of sapphire substrate. The crystal structure, surface morphology and epitaxial relationship of the films were investigated. It was confirmed that the ECR-assisted MBE technique was capable of growing a high quality epitaxial ZnO films on c-plane sapphire substrates at low temperatures in comparison with CVD and RF sputtering. The FWHM of an x-ray rocking curve of the (0002) peak for a 0.33μ-thick ZnO film was as narrow as 0.58°. The epitaxial relationship between ZnO film and c-plane sapphire substrate was determined to be (0001)ZnO//(0001)Al2O3 with in-plane alignment of [1100]ZnO//[2110]Al2O3, which is equivalent to the 30° rotation of ZnO relative to sapphire in the c-plane.

Effects of Sapphire Substrate Configurations on MBE Growth of ZnO

1999 ◽  
Vol 587 ◽  
Author(s):  
Keiichiro Sakurai ◽  
Ken Nakahara ◽  
Tetsuhiro Tanabe ◽  
Shizuo Fujita ◽  
Shigeo Fujita
Keyword(s):  
Surface Morphology ◽  
Sapphire Substrate ◽  
Film Growth ◽  
Semiconductor Devices ◽  
Optical Characteristics ◽  
Zno Films ◽  
Zno Film ◽  
Mbe Growth ◽  
Sapphire Substrates ◽  
Sensitive Factor

AbstractMBE growth of ZnO films for optical semiconductor devices was investigated on off-angled c-plane sapphire substrates. Twin crystal RHEED patterns and surface facetting observed with c-plane just-oriented substrates were suppressed by enlarging the offset angles from near-zero to 2.87 degrees. Though no significant changes were seen in optical characteristics, FWHM of XRC narrowed and surface morphology improved with larger offset angles, indicating that the offset angle is also a sensitive factor for ZnO film growth.

Epitaxial relationship of ZnO film with Si (001) substrate and its effect on growth and morphology

2006 ◽  
Vol 88 (25) ◽  
pp. 251911 ◽  
Author(s):  
Z. W. Liu ◽  
C. W. Sun ◽  
J. F. Gu ◽  
Q. Y. Zhang
Keyword(s):  
Zno Film ◽  
Epitaxial Relationship ◽  
Relationship Of ◽  
Effect On Growth

Substrate Temperature Effects of the ZnO:AlF3Transparent Conductive Oxide

2013 ◽  
Vol 1494 ◽  
pp. 91-97
Author(s):  
Tien-Chai Lin ◽  
Wen-Chang Huang ◽  
Chin-Hung Liu ◽  
Shang-Chou Chang
Keyword(s):  
Substrate Temperature ◽  
Carrier Concentration ◽  
Electron Mobility ◽  
Thermal Effects ◽  
Rf Sputtering ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Zno Films ◽  
Zno Film

ABSTRACTThermal effects on the crystal structure, electrical and optical characteristics of the Al and F co-doped ZnO films (ZnO:AlF3) are discussed in the paper. The ZnO:AlF3 thin films are prepared by RF sputtering with a constant power (ZnO/AlF3=100W/75W) toward the ZnO and AlF3 targets. The substrate temperature varied from room temperature to 250 °C with a step of 50 °C during thin film deposition. The crystalline quality of the ZnO:AlF3 film improved as the substrate temperature increased, with a corresponding increase in grain size. The improvement of the film quality leads to a higher electron mobility, with electron mobility of 0.85 cm2/V-s for the film deposited at the substrate temperature of 250 °C. The doping effect of fluorine in ZnO, and hence carrier concentration, was reduced at high temperature due to the vaporization of fluorine. This led to a reduction of carrier concentration with increase of temperature from 25 to 200°C. The corresponding resistivity increased from 3.60×10−2 to 6.0×10−2 Ω-cm. While for a further increase in substrate temperature, the doping of Al to the ZnO film was increased and resulted in an increase in carrier concentration.

Growth and microstructural characterization of catalyst-free ZnO nanostructures grown on sapphire and GaN by thermal evaporation

2007 ◽  
Vol 22 (4) ◽  
pp. 937-942 ◽  
Author(s):  
Bo Hyun Kong ◽  
Hyung Koun Cho
Keyword(s):  
Electron Microscopy ◽  
Thermal Evaporation ◽  
Lattice Mismatch ◽  
Zno Nanorods ◽  
Microstructural Characterization ◽  
Zno Nanostructures ◽  
Zno Film ◽  
Sapphire Substrates ◽  
Transmission Electron ◽  
Relationship Of

ZnO nanostructures were grown directly on sapphire substrates and GaN epilayers by thermal evaporation. Their morphologies and densities were found to be strongly dependent on the synthesis position and the kinds of substrate loaded into the reactor due to the different oxygen densities and the lattice mismatch, respectively. Scanning electron microscopy and transmission electron microscopy studies revealed that ZnO nanorods on sapphire substrates grew in four directions, one 〈0001〉Sapphire and three (1014)Sapphire directions. It was found that the in-plane lattice mismatch of inclined ZnO nanorods was remarkably reduced by forming the planar relationship of (0002)ZnO//(1014)Sapphire, compared to that of (1120)ZnO//(1010)Sapphire in the ZnO film. On the other hand, for the GaN epilayers, vertically well-aligned ZnO nanorods were grown after growing an epitaxial ZnO film due to reduced lattice mismatch. Electron energy-loss spectroscopy data showed that Zn-rich stoichiometry was responsible for the formation of ZnO nanostructures.

BaTiO3 Waveguides on MgO Buffered-Sapphire Single Crystals

1999 ◽  
Vol 597 ◽  
Author(s):  
Judit G. Lisoni ◽  
M. Siegert ◽  
C. H. Lei ◽  
C. L. Jia ◽  
J. Schubert ◽  
...  
Keyword(s):  
Optical Waveguides ◽  
Ferroelectric Thin Film ◽  
X Ray Diffraction ◽  
Epitaxial Relationship ◽  
Rocking Curve ◽  
Force Microscopy ◽  
Sapphire Substrates ◽  
Atomic Force ◽  
Transmission Electron ◽  
Good Crystalline Quality

AbstractWithin our program to develop ferroelectric thin film optical waveguides, we have studied the growth of epitaxial waveguides BaTiO3 on r-plane sapphire substrates with a MgO buffer layer. The films were prepared by pulsed laser deposition (PLD). Their structural properties were studied by X-ray diffraction (XRD), transmission electron microscopy (TEM), Rutherford backscattering (RBS) in random and channeling (RBS-c) configuration and atomic force microscopy (AFM). They displayed good crystalline quality, characterized by an RBS-c minimum yield of about 4–6%, a full width at half maximum (FWHM) of the XRD rocking curve measurement of the BaTiO3(200) reflection of 0.32° and a rms roughness of 1.2 nm in a film of ∼ 1.0 μm thickness. The epitaxial relationship was found to be BaTiO3(100) // MgO(100) // A12O3(1102). The refractive index, the birefringence and the optical losses have been measured.

C-Axis Oriented ZnO Film by RF Sputtering and its Integration with MEMS Processing

2007 ◽  
Vol 1052 ◽  
Author(s):  
Sudhir Chandra ◽  
Ravindra Singh
Keyword(s):  
Resistivity Measurement ◽  
Mechanical Systems ◽  
Rf Sputtering ◽  
Fabrication Process ◽  
Zno Films ◽  
Front Side ◽  
Zno Film ◽  
Micro Electro Mechanical Systems ◽  
Mems Fabrication ◽  
Film Side

AbstractIn the present work, we report a new fabrication process to integrate the “c-axis oriented” ZnO films with bulk-micromachined silicon diaphragms. ZnO films are very sensitive to the chemicals used in the micro-electro-mechanical systems (MEMS) fabrication process which include acids, bases and etchants of different material layers (e.g. SiO2, chromium, gold etc.). A Si3N4 layer is incorporated to protect the ZnO film from the etchants of chromium and gold used for patterning the electrodes. A mechanical jig is used for protecting the front side (ZnO film side) of the wafer from ethylenediamine pyrocatechol water (EPW) during the anisotropic etching of silicon. The resistivity measurement performed on the ZnO film integrated with micro-diaphragm shows the reliability of the fabrication process proposed in this work.

Structural, Electrical, and Optical Properties of Erbium-Doped Epitaxial BaTiO3 Films Grown by RF Sputtering

1995 ◽  
Vol 401 ◽  
Author(s):  
Pedro Barrios ◽  
Cheng Chung Li ◽  
Hong Koo Kim ◽  
Jean Blachere
Keyword(s):  
Remanent Polarization ◽  
Rf Sputtering ◽  
Rf Magnetron Sputtering ◽  
X Ray Diffraction ◽  
Epitaxial Relationship ◽  
Electrical And Optical Properties ◽  
Buffer Electrode ◽  
Erbium Doped ◽  
Er Doped ◽  
Relationship Of

AbstractWe have investigated the epitaxial growth of Er-doped BaTiO3 films using rf magnetron sputtering. The Er-doped films (0.5 - 1 μm thick) were deposited on MgO (001) single-crystal substrates at various temperatures (500 - 800 °C). The films deposited at 700 °C or above arehighly (001)- oriented with an in-plane epitaxial relationship of BaTiO3[100] ║ MgO[100], as confirmed by X-ray diffraction. The Er doped films were found to be compressively stressed, as-deposited. The amount of stress monotonically decreases as a function of the deposition temperature. The Er-doped epitaxial films show a strong room-temperature photoluminescence at 1.54 μm, which corresponds to intra-transitions of Er3+ ions. Electrical characterizationswere carried out on Er-doped BaTiO3 films that were grown on MgO with a conducting In203 buffer electrode. The measurement shows that the Er-doped BaTiO3 films are ferroelectric with a remanent polarization of 1.5 μC/cm2 and a coercive field of 40 kV/cm.

Control of in-plane epitaxial relationship of c -plane AlN layers grown on a -plane sapphire substrates by hydride vapor phase epitaxy

2011 ◽  
Vol 8 (7-8) ◽  
pp. 2028-2030 ◽  
Author(s):  
Jumpei Tajima ◽  
Rie Togashi ◽  
Hisashi Murakami ◽  
Yoshinao Kumagai ◽  
Kazuya Takada ◽  
...  
Keyword(s):  
Vapor Phase ◽  
Vapor Phase Epitaxy ◽  
Hydride Vapor Phase Epitaxy ◽  
Epitaxial Relationship ◽  
Sapphire Substrates ◽  
Relationship Of

Sputter Epitaxy of (ZnO)x(InN)1-x films on Lattice-mismatched Sapphire Substrate

MRS Advances ◽  
2019 ◽  
Vol 4 (27) ◽  
pp. 1551-1556 ◽  
Author(s):  
Nanoka Miyahara ◽  
Seichi Urakawa ◽  
Daisuke Yamashita ◽  
Kunihiro Kamataki ◽  
Kazunori Koga ◽  
...  
Keyword(s):  
Epitaxial Growth ◽  
Sapphire Substrate ◽  
Rf Magnetron Sputtering ◽  
X Ray Diffraction ◽  
Island Growth ◽  
Epitaxial Relationship ◽  
Crystal Axis ◽  
Sapphire Substrates ◽  
Initial Nucleation ◽  
Three Stages

ABSTRACTWe have recently developed a novel semiconductor, (ZnO)x(InN)1-x (abbreviated to ZION). In this study, we have succeeded in direct epitaxial growth of ZION films on 19–21%-lattice-mismatched c-plane sapphire by radio-frequency (RF) magnetron sputtering. X-ray diffraction analysis showed that there is no epitaxial relationship between ZION films fabricated at room-temperature (RT) and the sapphire substrates, while the films fabricated at 450oC grow epitaxially on the sapphire substrates. From the analysis of time evolution of the surface morphology, the process for the epitaxial growth of ZION on sapphire is found to consist of three stages. They are (i) initial nucleation of ZION crystallites with crystal axis aligned to the sapphire substrate, (ii) island growth from the initially formed nuclei and subsequent nucleation (secondary nucleation) of ZION crystallites, and (iii) lateral growth of ZION islands originated from initially formed nuclei. On the other hand, non-epitaxial ZION films fabricated at RT just grow in 3D mode. From these results, we conclude that the substrate temperature is the key to control of nucleation and subsequent epitaxial growth of ZION films on the lattice-mismatched substrate.

Influence of Mis-Orientation of C-plane Sapphire Substrate on the Early Stages of MOCVD Growth of GaN Thin Films

2004 ◽  
Vol 831 ◽  
Author(s):  
Seong-woo Kim ◽  
Hideo Aida ◽  
Toshimasa Suzuki
Keyword(s):  
Thin Films ◽  
Sapphire Substrate ◽  
Orientation Angle ◽  
Rocking Curve ◽  
Sapphire Substrates ◽  
Early Stages ◽  
Mocvd Growth ◽  
The Difference ◽  
Afm Observation

ABSTRACTWe have studied the early stages of GaN growth to realize the growth mechanism of GaN thin films on mis-oriented sapphire substrates which affects the surface and crystal quality of GaN thin films. As the result, it was found that the larger mis-orientation angle helps the growth of the larger grain of GaN and leads to the earlier shift of growth mode from 3D to 2D. The AFM observation of closed-coalesced GaN thin films revealed the difference in the micro-step structures by the mis-orientation angle of sapphire substrate. The result of x-ray rocking curve as a function of mis-orientation angle well matched with the microstructure of GaN surface, indicating that the larger mis-orientation angle helps the column ordering of GaN crystals.

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