scholarly journals Growth and Properties of InGaN and AlInGaN Thin Films on (0001) Sapphire

1996 ◽  
Vol 1 ◽  
Author(s):  
E. L. Piner ◽  
F. G. McIntosh ◽  
J. C. Roberts ◽  
M. E. Aumer ◽  
V. A. Joshkin ◽  
...  
Keyword(s):  
Thin Films ◽  
Growth Parameters ◽  
Band Edge Emission ◽  
High Quality ◽  
Electrical And Optical Properties ◽  
Double Crystal ◽  
Lattice Constants ◽  
Mocvd Reactor ◽  
Vegard’S Law ◽  
Lattice Matched

High quality InGaN films have led to the development of LEDs and blue lasers. The quaternary AlInGaN however, represents a more versatile material since the bandgap and lattice constant can be independently varied. We report on such films grown on (0001) sapphire substrates in an atmospheric pressure MOCVD reactor at 750-800°C. The ternary films have a composition of up to 40% InN and the quaternary films were grown in the composition range of 0 to 20% AlN and 0 to 20% InN. The quaternary compositions studied by EDS and the lattice constants from double crystal XRD followed Vegard's law indicating solid solubility for the range studied. Room temperature PL is dominated by band edge emission for InGaN and AlInGaN, at low AlN%. Higher AlN alloys of AlInGaN had PL dominated by deep levels. AlInGaN/InGaN and AlGaN/InGaN heterostructures were grown with abrupt interfaces. We emphasize the most important growth parameters for the growth of high quality ternary and quaternary thin films. The structural, electrical and optical properties of these In-based ternary and quaternary films and their lattice matched and strained heterostructures will also be presented.

AlGaInN Quaternary Alloys by MOCVD

1995 ◽  
Vol 395 ◽  
Author(s):  
F.G. Mcintosh ◽  
E. Piner ◽  
K. Boutros ◽  
J.C. Roberts ◽  
Y. He ◽  
...  
Keyword(s):  
Quaternary Alloy ◽  
Growth Conditions ◽  
Band Edge Emission ◽  
X Ray Diffraction ◽  
Quaternary Alloys ◽  
Edge Emission ◽  
Lattice Constants ◽  
Mocvd Growth ◽  
Vegard’S Law ◽  
Lattice Matched

ABSTRACTAlGaInN quaternary alloy based devices can cover the emission wavelength from deep UV to red. This Quaternary alloy also offers lattice matched heterostructures for both optical and microwave devices. We will report on the MOCVD growth of AlxGa1−x-yInyN (0<x<0.12), (0<y<0.15) at 750 °C on sapphire substrates, using TMG, EDMIn, TMAl and NH3 precursors. Chemical composition, lattice constants and bandgaps of the grown films were determined by EDS, X-ray diffraction and room temperature PL. Data indicates that the lattice constants can also be deduced using Vegard's law, indicating a solid solution of this alloy. PL showed band edge emission, however emission from deep levels was also observed. Optimized growth conditions and heterostructures using this quaternary alloy will be presented.

Analysis of ZAO Thin Films by DC Reaction Magnetron Sputtereing

2011 ◽  
Vol 687 ◽  
pp. 585-590
Author(s):  
Feng Lu ◽  
Cheng Hai Xu ◽  
Li Shi Wen
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Magnetron Sputtering ◽  
Visible Region ◽  
Hexagonal Wurtzite Structure ◽  
Wurtzite Structure ◽  
Crystal Phase ◽  
High Quality ◽  
Electrical And Optical Properties ◽  
Polycrystalline Hexagonal Wurtzite Structure

The high quality ZAO thin films were produced by DC reaction magnetron sputtering technology. The XRD, electrical and optical properties of ZAO thin films were particularly investigated. The results show that ZAO films are polycrystalline hexagonal wurtzite structure，and Al2O3 crystal phase are not found. At the same time，the high quality ZAO films with the minimum resistivity of 4.5x×10-4Ω·㎝, the transmittance in visible region above 80% and the reflectivity in IR region above 70% are gained.

Properties of Al Doped ZnO Thin films by DC Reaction Magnetron Sputtering

2011 ◽  
Vol 306-307 ◽  
pp. 362-367
Author(s):  
Feng Lu ◽  
Yu Sun ◽  
Cheng Hai Xu
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Magnetron Sputtering ◽  
Visible Region ◽  
Hexagonal Wurtzite Structure ◽  
Zno Thin Films ◽  
High Quality ◽  
Electrical And Optical Properties ◽  
Polycrystalline Hexagonal Wurtzite Structure ◽  
Doped Zno

The high quality ZAO thin films were successfully produced by DC reaction magnetron sputtering technology. The XRD，electrical and optical properties of films are particular investigated. The results show that ZAO films are polycrystalline hexagonal wurtzite structure，and Al2O3 crystal phase are not found. At the same time，the high quality ZAO films with the minimum resistivity of 4.5x10-4Ω•㎝, the transmittance in visible region above 80% and the reflectivity in IR region above 70% are gained.

High-Quality InGaAsP Crystals Grown by MOVPE Using TBA and TBP

1990 ◽  
Vol 216 ◽  
Author(s):  
A. Kuramata ◽  
S. Yasmazaki ◽  
K. Nakajima
Keyword(s):  
Optical Properties ◽  
Growth Conditions ◽  
Band Edge Emission ◽  
Photoluminescence Spectra ◽  
Edge Emission ◽  
High Quality ◽  
Electrical And Optical Properties ◽  
Group V ◽  
Movpe Growth ◽  
The Relationship

ABSTRACTTBA and TBP are attractive candidates for group V sources for MOVPE growth from the viewpoint of safety. We studied how the composition of InGaAsP crystals depends on growth conditions, and investigated its electrical and optical properties. The relationship between group V sources and crystals indicates that TBA and TBP decompose into AsH and PH. Since there is no carbon in AsH and PH, carbon contamination in the crystals is expected to be small. Carrier concentrations ranged from 5×1014 cm−3 to 1.5×1015 cm−3. Photoluminescence spectra at 4.2K showed strong band-edge emission with no acceptor-related emission. Based on the electrical and optical properties of the crystals, we conclude that high-quality InGaAsP crystals can be grown using TBA and TBP.

MBE-grown NiyMg1-yO and ZnxMg1-xO Thin Films for Deep Ultraviolet Optoelectronic Applications

2009 ◽  
Vol 1201 ◽  
Author(s):  
Jeremy West Mares ◽  
Ryan Casey Boutwell ◽  
Matthew Thomas Falanga ◽  
Amber Scheurer ◽  
Winston Vaughan Schoenfeld
Keyword(s):  
Thin Films ◽  
Electrical Characterization ◽  
Heteroepitaxial Growth ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Lattice Constants ◽  
Atomic Force ◽  
Zn Concentration ◽  
Deep Ultraviolet ◽  
Lattice Matched

AbstractWe report on the heteroepitaxial growth of high-quality single crystal cubic ZnxMg1-xO and NiyMg1-yO thin films by radio frequency oxygen plasma-assisted molecular beam epitaxy (RF-MBE). Film compositions over the ranges x = 0 to x = 0.65 and y = 0 to y = 1 have been grown on lattice-matched MgO (100) and characterized optically, morphologically, compositionally, and electrically. Both of these ternary materials are shown to have bandgaps which vary directly as a function of transition metal (Ni or Zn) concentration. Optical transmission measurements of NiyMg1-yO show the bandgap to shift continuously over the approximate range 3.5 eV (for NiO) to 4.81 eV (for y=0.075). Similarly, the bandgap of cubic ZnxMg1-xO is shifted from about 4.9 eV (for x = 0.65) to 6.25 eV (for x=0.12). Films exhibit good morphological quality and typical roughness of NiyMg1-yO films is 5 Å while that of ZnxMg1-xO is less than 15 Å, as measured by atomic force microscopy (AFM). X-ray diffraction (XRD) is employed to confirm crystal orientation and to determine the films' lattice constants. Film compositions are interrogated by Rutherford Backscattering (RBS) and electrical characterization is made by room-temperature Hall measurements.

Undoped and doped GaN thin films deposited on high-temperature monocrystalline AlN buffer layers on vicinal and on-axis α(6H)–SiC(0001) substrates via organometallic vapor phase epitaxy

1996 ◽  
Vol 11 (4) ◽  
pp. 1011-1018 ◽  
Author(s):  
T. Warren Weeks ◽  
Michael D. Bremser ◽  
K. Shawn Ailey ◽  
Eric Carlson ◽  
William G. Perry ◽  
...  
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Buffer Layers ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Double Crystal ◽  
Strong Bound ◽  
Hall Effect Measurements ◽  
Excitonic Emission ◽  
Aln Buffer

Monocrystalline GaN(0001) thin films have been grown at 950 °C on high-temperature, ≈ 100 nm thick, monocrystalline AlN(0001) buffer layers predeposited at 1100 °C on α(6H)−SiC(0001)Si substrates via OMVPE in a cold-wall, vertical, pancake-style reactor. These films were free of low-angle grain boundaries and the associated oriented domain microstructure. The PL spectra of the GaN films deposited on both vicinal and on-axis substrates revealed strong bound excitonic emission with a FWHM value of 4 meV. The near band-edge emission from films on the vicinal substrates was shifted slightly to a lower energy, indicative of films containing residual tensile stresses. A peak attributed to free excitonic emission was also clearly observed in the on-axis spectrum. Undoped films were too resistive for accurate Hall-effect measurements. Controlled n-type, Si-doping in GaN was achieved for net carrier concentrations ranging from approximately 1 × 1017 cm−3 to 1 × 1020 cm−3. Mg-doped, p-type GaN was achieved with nA−nD ≈ 3 × 1017 cm−3, ρ ≈ 7 Ω · cm, and μ ≈ 3 cm2/V · s. Double-crystal x-ray rocking curve measurements for simultaneously deposited 1.4 μm GaN films revealed FWHM values of 58 and 151 arcsec for deposition on on-axis and off-axis 6H−SiC(0001)Si substrates, respectively. The corresponding FWHM values for the AlN buffer layers were approximately 200 and 400 arcsec, respectively.

ON THE STRUCTURE, ELECTRICAL AND OPTICAL PROPERTIES OF TiO2 SPUTTERED THIN FILMS

2006 ◽  
Vol 13 (01) ◽  
pp. 87-92 ◽  
Author(s):  
A. ASHOUR
Keyword(s):  
Thin Films ◽  
Optical Constants ◽  
Optical Band Gap ◽  
Optical Transmittance ◽  
X Ray Diffraction ◽  
Electrical And Optical Properties ◽  
X Ray ◽  
Lattice Constants ◽  
Glass Substrates ◽  
Deposited Films

Titanium oxide thin films were prepared by sputtering technique onto glass substrates at room temperature (RT). The structure of the films was confirmed using X-ray diffraction (XRD) and revealed the stoichiometry with an O and Ti ratio of 2. The deposited films at RT were found to be amorphous and the films annealed at 300 and 400°C for 2 h were crystalline with orthorhombic structure. The lattice constants and grain size of the film are calculated. The electrical resistivity was found to depend on the film thickness and decreased with increasing the film thicknesses. The optical constants of the films such as the refractive index, extinction coefficient, and absorption coefficient were also determined using the optical transmittance measurements, and the results were discussed. The optical band gap varies from 3.2 to 3.5 eV as a function of oxygen/argon ratios.

Ion Beam Sputter Deposition Of Ferroelectric Oxide Thin Films

1991 ◽  
Vol 223 ◽  
Author(s):  
Thomas M. Graettinger ◽  
O. Auciello ◽  
M. S. Ameen ◽  
H. N. Al-Shareef ◽  
K. Gifford ◽  
...  
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Growth Parameters ◽  
Ion Beam ◽  
Lead Zirconate ◽  
Electro Optic ◽  
Integrated Optical ◽  
Pzt Films ◽  
Ion Beam Sputter Deposition ◽  
Ferroelectric Oxide

ABSTRACTFerroelectric oxide films have been studied for their potential application as integrated optical materials and nonvolatile memories. Electro-optic properties of potassium niobate (KNbO3) thin films have been measured and the results correlated to the microstructures observed. The growth parameters necessary to obtain single phase perovskite lead zirconate titanate (PZT) thin films are discussed. Hysteresis and fatigue measurements of the PZT films were performed to determine their characteristics for potential memory devices.

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