Characterization of zinc oxide single crystals for epitaxial wafer applications

ABSTRACTZinc oxide (ZnO) single crystals were grown by the hydrothermal method using lithium and potassium hydroxide as mineralizer and properties of the grown crystals were characterized from the viewpoints of epitaxial wafer applications. The growth sector dependence of impurity and defect concentrations were characterized by secondary ion mass spectroscopy and photoluminescence. As a result, it was clearly shown that defect and impurity distribution in the obtained crystal was anisotropic, and this anisotropy is affected by the choice of the seed crystal shape and growth direction. Annealing effect on flatness of the wafer surface was also examined, and it was found that high temperature annealing with flat single crystalline cover is appropriate for removal of scratch and formation of atomically flat surface. Moreover, we show the possible miss-evaluation of Hall coefficient of ZnO due to anisotropy in defects and impurities distributions.

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Planarization of Zinc Oxide Surface and Evaluation of Processing Damage

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.485.215 ◽

2011 ◽

Vol 485 ◽

pp. 215-218 ◽

Cited By ~ 3

Author(s):

Hiroki Miyazaki ◽

Yutaka Adachi ◽

Isao Sakaguchi ◽

Takamasa Ishigaki ◽

Naoki Ohashi

Keyword(s):

Zinc Oxide ◽

Flat Surface ◽

Mechanical Polishing ◽

Crystalline Quality ◽

Polished Surface ◽

Oxide Surface ◽

High Crystalline Quality ◽

Atomically Flat

The processes for polishing a ZnO surface were investigated with the aim of establishing a process for obtaining an atomically flat surface with high crystalline quality. The defects in a layer undergoing mechanical polishing were monitored through photoluminescence measurements, and the purity of the polished surface was characterized by SIMS. An atomicallyfishing process.

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Nonlinear Current-Voltage Characteristics of Homojunctions Made by Zinc Oxide Single Crystals

MRS Proceedings ◽

10.1557/proc-458-343 ◽

1996 ◽

Vol 458 ◽

Cited By ~ 1

Author(s):

Takeshi Harada ◽

Yoshinobu Nakamura ◽

Akira Kishimoto ◽

Naobumi Motohira ◽

Hiroaki Yanagida

Keyword(s):

Zinc Oxide ◽

Single Crystals ◽

Electrical Characterization ◽

Earth Metal ◽

Chemical Vapor ◽

Current Voltage ◽

Zno Varistors ◽

Zno Crystal ◽

Single Boundary

ABSTRACTZinc oxide (ZnO) single crystals are grown by the traditional chemical vapor reaction method and ZnO crystal pairs with a single boundary are successfully obtained. The obtained specimens with one ZnO–ZnO boundary (ZnO homojunction) show nonlinear current-voltage (I–V) characteristics without the addition of Bi2O3, CoO, MnO2, and/or rare earth metal oxides. A specimen with higher breakdown voltage shows superior nonlinearity with negative resistivity in its I–V characteristics. Electrical characterization of the ZnO homojunction is conducted and extremely slow response with the current (or voltage) stress is confirmed. The phenomenon had never been observed in commercial ZnO varistors. The surface temperature of the ZnO homojunction is enhanced by larger applied current. The effect of the Joule heat on the nonlinearity in the I–V curves of the ZnO homojunction is discussed.

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Secondary ion mass spectrometry characterization of NdBa2Cu3O7−x and EuBa2Cu3O7−x single crystals

Rapid Communications in Mass Spectrometry ◽

10.1002/(sici)1097-0231(19980615)12:11<675::aid-rcm216>3.0.co;2-o ◽

1998 ◽

Vol 12 (11) ◽

pp. 675-682

Author(s):

M. Fabrizio ◽

C. Pagura ◽

A. Tolstogouzov ◽

S. Daolio ◽

M. Ferretti ◽

...

Keyword(s):

Mass Spectrometry ◽

Single Crystals ◽

Secondary Ion Mass Spectrometry ◽

Ion Mass Spectrometry ◽

Secondary Ion

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Study of Defects in High Energy Ion Implanted ZnO Crystals

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.373.193 ◽

2017 ◽

Vol 373 ◽

pp. 193-196

Author(s):

Oksana Melikhova ◽

Jakub Čížek ◽

Ivan Procházka ◽

Petr Hruška ◽

Wolfgang Anwand ◽

...

Keyword(s):

Zinc Oxide ◽

Single Crystals ◽

Positron Annihilation Spectroscopy ◽

High Energy ◽

Hydrogen Ion ◽

Vacancy Clusters ◽

High Energy Ions ◽

Hydrogen Ion Implantation ◽

Mev Protons

Positron annihilation spectroscopy (PAS) was employed for characterization of defects in the hydrothermally (HT) grown zinc oxide single crystals irradiated by high energy ions. Defects created in ZnO crystals by 2.5 MeV protons, 7.5 MeV N3+ and 167 MeV Xe26+ ions were compared. The virgin ZnO crystals contain Zn-vacancies associated with hydrogen. Ion implantation introduced additional defects, namely Zn+O di-vacancies in crystals irradiated by protons and small vacancy clusters in samples implanted by N and Xe ions.

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Growth and Characterization of Sulfur-doped GaSe Single Crystals

Journal of Inorganic Materials ◽

10.15541/jim20150032 ◽

2015 ◽

Vol 30 (8) ◽

pp. 887 ◽

Cited By ~ 2

Author(s):

HUANG Chang-Bao ◽

NI You-Bao ◽

WU Hai-Xin ◽

WANG Zhen-You ◽

XIAO Rui-Chun ◽

...

Keyword(s):

Single Crystals

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Characterization and Elimination of Forward Snapback Defects in GaAs Light Emitting Diodes

ISTFA 1996: Conference Proceedings from the 22nd International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa1996p0239 ◽

1996 ◽

Author(s):

J. Zimmer ◽

D. Nielsen ◽

T.A. Anderson ◽

M. Schade ◽

N. Saha ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Light Emitting Diode ◽

Elevated Concentration ◽

Forward Voltage ◽

Light Emitting ◽

Intermittent Yield ◽

Si Doped ◽

Secondary Ion ◽

Furnace Pressure

Abstract The p-n junction of a GaAs light emitting diode is fabricated using liquid phase epitaxy (LPE). The junction is grown on a Si doped (~1018/cm3) GaAs substrate. Intermittent yield loss due to forward voltage snapback was observed. Historically, out of specification forward voltage (Vf) parameters have been correlated to abnormalities in the junction formation. Scanning electron (SEM) and optical microscopy of cleaved and stained samples revealed a continuous layer of material approximately 2.5 to 3.0 urn thick at the n-epi/substrate interface. Characterization of a defective wafer via secondary ion mass spectroscopy (SIMS) revealed an elevated concentration of O throughout the region containing the defect. X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES) data taken from a wafer prior to growth of the epi layers did not reveal any unusual oxidation or contamination. Extensive review of the processing data suggested LPE furnace pressure was the obvious source of variability. Processing wafers through the LPE furnace with a slight positive H2 gas pressure has greatly reduced the occurrence of this defect.

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