High tunability (Ba,Sr)TiO3 thin films grown on atomic layer deposited TiO2 and Ta2O5 buffer layers

2004 ◽  
Vol 85 (20) ◽  
pp. 4705-4707 ◽  
Author(s):  
Il-Doo Kim ◽  
Harry L. Tuller ◽  
Hyun-Suk Kim ◽  
Jin-Seong Park
Keyword(s):  
Thin Films ◽  
Atomic Layer ◽  
Buffer Layers ◽  
High Tunability

scholarly journals High-Temperature Atomic Layer Deposition of GaN on 1D Nanostructures

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2434
Author(s):  
Aaron J. Austin ◽  
Elena Echeverria ◽  
Phadindra Wagle ◽  
Punya Mainali ◽  
Derek Meyers ◽  
...  
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Atomic Layer Deposition ◽  
Buffer Layer ◽  
Atomic Layer ◽  
Buffer Layers ◽  
X Ray ◽  
1D Nanostructures ◽  
Layer Deposition ◽  
Silica Nanosprings

Silica nanosprings (NS) were coated with gallium nitride (GaN) by high-temperature atomic layer deposition. The deposition temperature was 800 °C using trimethylgallium (TMG) as the Ga source and ammonia (NH3) as the reactive nitrogen source. The growth of GaN on silica nanosprings was compared with deposition of GaN thin films to elucidate the growth properties. The effects of buffer layers of aluminum nitride (AlN) and aluminum oxide (Al2O3) on the stoichiometry, chemical bonding, and morphology of GaN thin films were determined with X-ray photoelectron spectroscopy (XPS), high-resolution x-ray diffraction (HRXRD), and atomic force microscopy (AFM). Scanning and transmission electron microscopy of coated silica nanosprings were compared with corresponding data for the GaN thin films. As grown, GaN on NS is conformal and amorphous. Upon introducing buffer layers of Al2O3 or AlN or combinations thereof, GaN is nanocrystalline with an average crystallite size of 11.5 ± 0.5 nm. The electrical properties of the GaN coated NS depends on whether or not a buffer layer is present and the choice of the buffer layer. In addition, the IV curves of GaN coated NS and the thin films (TF) with corresponding buffer layers, or lack thereof, show similar characteristic features, which supports the conclusion that atomic layer deposition (ALD) of GaN thin films with and without buffer layers translates to 1D nanostructures.

High-tunability and low-microwave-loss Ba0.6Sr0.4TiO3 thin films grown on high-resistivity Si substrates using TiO2 buffer layers

2005 ◽  
Vol 87 (21) ◽  
pp. 212903 ◽  
Author(s):  
Hyun-Suk Kim ◽  
Ho-Gi Kim ◽  
Il-Doo Kim ◽  
Ki-Byoung Kim ◽  
Jong-Chul Lee
Keyword(s):  
Thin Films ◽  
Buffer Layers ◽  
High Resistivity ◽  
Si Substrates ◽  
High Tunability ◽  
Microwave Loss

Issues and Examples Regarding Growth of AlN, GaN and AlxGa1−xN Thin Films via OMVPE and Gas Source MBE

1995 ◽  
Vol 395 ◽  
Author(s):  
Robert F. Davis ◽  
T. W. Weeks ◽  
M. D. Bremser ◽  
S. Tanaka ◽  
R. S. Kern ◽  
...  
Keyword(s):  
Thin Films ◽  
Nitrogen Sources ◽  
Atomic Layer ◽  
Growth Direction ◽  
Buffer Layers ◽  
Acceptor Doping ◽  
Light Emitting ◽  
Surface Migration ◽  
Donor And Acceptor ◽  
Layer Stacking

ABSTRACTOrganometallic vapor phase epitaxy (OMVPE) and molecular beam epitaxy (MBE) are the most common methods for the growth of thin films of A1N and GaN. Sapphire is the most common substrate; however, a host of materials have been used with varying degrees of success. Both growth techniques have been employed by the authors to grow AIN, GaN and AlxGa1−xN thin films primarily on 6H-SiC(0001). The mismatch in atomic layer stacking sequences along the growth direction produces double positioning boundaries in A1N and the alloys at the SiC steps; this sequence problem appears to discourage the two-dimensional nucleation of GaN. Films of these materials grown by MBE at 650°C are textured; monocrystalline films are achieved between 850°C (pure GaN) and 1050°C (pure A1N) by this technique and OMVPE. Donor and acceptor doping of GaN has been achieved via MBE without post growth annealing. Acceptor doping in CVD material requires annealing to displace the H from the Mg and eventually remove it from the material. High brightness light emitting diodes are commercially available; however, numerous concerns regarding metal and nitrogen sources, heteroepitaxial nucleation, the role of buffer layers, surface migration rates as a function of temperature, substantial defect densities and their effect on film and device properties, ohmic and rectifying contacts, wet and dry etching and suitable gate and field insulators must and are being addressed. Selected issues surrounding the growth of these materials with particular examples drawn from the authors' research are presented herein.

{10} edge dislocations in YSZ films grown on (100)MgO by PLD

1994 ◽  
Vol 52 ◽  
pp. 530-531
Author(s):  
Jason R. Heffelfinger ◽  
C. Barry Carter
Keyword(s):  
Thin Films ◽  
Semiconductor Lasers ◽  
Vapor Deposition ◽  
Substrate Surface ◽  
Laser System ◽  
Average Energy ◽  
Target Material ◽  
Chemical Vapor ◽  
Buffer Layers ◽  
Organic Chemical

Yttria-stabilized zirconia (YSZ) is currently used in a variety of applications including oxygen sensors, fuel cells, coatings for semiconductor lasers, and buffer layers for high-temperature superconducting films. Thin films of YSZ have been grown by metal-organic chemical vapor deposition, electrochemical vapor deposition, pulse-laser deposition (PLD), electron-beam evaporation, and sputtering. In this investigation, PLD was used to grow thin films of YSZ on (100) MgO substrates. This system proves to be an interesting example of relationships between interfaces and extrinsic dislocations in thin films of YSZ.In this experiment, a freshly cleaved (100) MgO substrate surface was prepared for deposition by cleaving a lmm-thick slice from a single-crystal MgO cube. The YSZ target material which contained 10mol% yttria was prepared from powders and sintered to 85% of theoretical density. The laser system used for the depositions was a Lambda Physik 210i excimer laser operating with KrF (λ=248nm, 1Hz repetition rate, average energy per pulse of 100mJ).

scholarly journals On the Use of MOFs and ALD Layers as Nanomembranes for the Enhancement of Gas Sensors Selectivity

Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1552 ◽  
Author(s):  
Weber ◽  
Graniel ◽  
Balme ◽  
Miele ◽  
Bechelany
Keyword(s):  
Thin Films ◽  
Gas Sensors ◽  
Gas Sensing ◽  
Metal Organic Frameworks ◽  
Atomic Layer ◽  
Operational Performance ◽  
Layer Deposition ◽  
Metal Organic ◽  
Further Development ◽  
Different Gases

Improving the selectivity of gas sensors is crucial for their further development. One effective route to enhance this key property of sensors is the use of selective nanomembrane materials. This work aims to present how metal-organic frameworks (MOFs) and thin films prepared by atomic layer deposition (ALD) can be applied as nanomembranes to separate different gases, and hence improve the selectivity of gas sensing devices. First, the fundamentals of the mechanisms and configuration of gas sensors will be given. A selected list of studies will then be presented to illustrate how MOFs and ALD materials can be implemented as nanomembranes and how they can be implemented to improve the operational performance of gas sensing devices. This review comprehensively shows the benefits of these novel selective nanomaterials and opens prospects for the sensing community.

Atomic Layer Modulation of Multicomponent Thin Films through Combination of Experimental and Theoretical Approaches

2021 ◽  
Author(s):  
Chi Thang Nguyen ◽  
Bonwook Gu ◽  
Taehoon Cheon ◽  
Jeongwoo Park ◽  
Mohammad Rizwan Khan ◽  
...  
Keyword(s):  
Thin Films ◽  
Atomic Layer ◽  
Theoretical Approaches
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