Microstructure and Strain in GaAs/AlGaAs MQW thin Films Bonded to Different Substrates by Eutectic Alloying

1994 ◽  
Vol 356 ◽  
Author(s):  
C. H. Lin ◽  
H. C. Kuo ◽  
Y. Lu ◽  
H. Shen ◽  
J. Pamulapati ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electron Microscope ◽  
Plane Strain ◽  
Multiple Quantum Well ◽  
Strain Effect ◽  
Multiple Quantum ◽  
New Device ◽  
Device Applications ◽  
Bonding Technique

AbstractResearch of the strain effect on semiconductors and their heterostructures has generated increasing interests due to its important device applications. We have developed a eutectic bonding technique to create in-plane anisotropic strain in GaAs/AlGaAs multiple quantum well (MQW) thin films. MQW thin films grown on (100) GaAs substrates were bonded to (100) GaAs, (100) Si and Y-cut LiNbO3 submounts with a Au/Sn eutectic alloy. The bonding materials consist of Au/Sn multilayer (80 wt% Au and 20 wt% Sn; 0.95μm) with a Cr (500Å) adhesion layer. The bonding process was optimized by carefully choosing the annealing conditions. After bonding, the substrates of the MQWs were removed by wet chemical etching. The in-plane strain was induced in MQW thin film due to the different thermal expansion between the thin film and submount. The strain was characterized using X-ray rocking curve. The microstructures of bonding interfaces and MQW thin films were examined by scanning electron microscope(SEM) and cross-section transmission electron microscope (XTEM). This bonding technique can be used for many new device applications which take the advantage of in-plane strain, as well as for device integration.

Eutectic Bonding for Inducing In-Plane Strain in Gaas and Gaas/Algaas MQW Thin Films

1994 ◽  
Vol 337 ◽  
Author(s):  
Y. Lu ◽  
H. C. Kuo ◽  
C. H. Lin ◽  
H. Shen ◽  
F. Ren ◽  
...  
Keyword(s):  
Thin Films ◽  
Plane Strain ◽  
Annealing Temperature ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
Adhesion Layer ◽  
Thermally Induced ◽  
New Class ◽  
Linearly Polarized ◽  
Reflectance Measurements

ABSTRACTWe present a process for creating in-plane anisotropic strain in (100) GaAs and GaAs/AlGaAs multiple quantum well (MQW) thin films. The host substrates used for bonding include (100) GaAs, (100) silicon, and lithium tantalate (LiTaO3) with a special crystalline orientation. A mutilayer metallization consisting of Au-Sn (Au: 80 wt% , Sn: 20 wt%, 0.95μm), Ti (500Å) adhesion layer and Pt (500Å) barrier layer is deposited on the thin films and the host substrates. By choosing a proper annealing temperature (380°C) and thickness of eutectic layer, the thin films and the substrates are bonded together. Photoluminescence measurements do not reveal any thermally induced strain in the thin films bonded to GaAs; however, they show the existence of in-plane biaxial strain in the films bonded on Si. Linearly polarized reflectance measurements reveal an optical anisotropy in the MQW bonded to LiTaO3, which possesses an orientation-dependent thermal expansion. This indicates that the in-plane strain in the thin films is induced by the different thermal expansions between the thin films and the substrates. This process can be used to develop a new class of devices with an artificially induced in-plane strain.

Optical study of lift-off multiple quantum well thin films under various types of thermally induced in-plane strain

1994 ◽  
Author(s):  
Hongen Shen ◽  
Michael Wraback ◽  
Jagadeesh Pamulapati ◽  
Monica A. Taysing-Lara ◽  
Weimin Zhou ◽  
...  
Keyword(s):  
Thin Films ◽  
Quantum Well ◽  
Plane Strain ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
Optical Study ◽  
Thermally Induced ◽  
Lift Off

Studies on Water in the Hydration Chamber of a Modified Electron Microscope

1970 ◽  
Vol 28 ◽  
pp. 544-545
Author(s):  
R. C. Moretz ◽  
G. G. Hausner ◽  
D. F. Parsons
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electron Microscope ◽  
Steady State ◽  
Room Temperature ◽  
Small Mass ◽  
Equilibrium Pressure ◽  
Biological Objects ◽  
Mechanical Pump ◽  
Differential Pumping

Use of the electron microscope to examine wet objects is possible due to the small mass thickness of the equilibrium pressure of water vapor at room temperature. Previous attempts to examine hydrated biological objects and water itself used a chamber consisting of two small apertures sealed by two thin films. Extensive work in our laboratory showed that such films have an 80% failure rate when wet. Using the principle of differential pumping of the microscope column, we can use open apertures in place of thin film windows.Fig. 1 shows the modified Siemens la specimen chamber with the connections to the water supply and the auxiliary pumping station. A mechanical pump is connected to the vapor supply via a 100μ aperture to maintain steady-state conditions.

scholarly journals Optoelectronic properties of highly porous silver oxide thin film

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Ahmad Al-Sarraj ◽  
Khaled M. Saoud ◽  
Abdelaziz Elmel ◽  
Said Mansour ◽  
Yousef Haik
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electron Microscope ◽  
Plasma Etching ◽  
Silver Oxide ◽  
Oxidation Time ◽  
Oxide Thin Film ◽  
X Ray ◽  
Porous Silver ◽  
Highly Porous

Abstract In this paper, we report oxidation time effect on highly porous silver oxide nanowires thin films fabricated using ultrasonic spray pyrolysis and oxygen plasma etching method. The NW’s morphological, electrical, and optical properties were investigated under different plasma etching periods and the number of deposition cycles. The increase of plasma etching and oxidation time increases the surface roughness of the Ag NWs until it fused to form a porous thin film of silver oxide. AgNWs based thin films were characterized using X-ray diffraction, scanning electron microscope, transmission electron microscope, X-ray photoemission spectroscopy, and UV–Vis spectroscopy techniques. The obtained results indicate the formation of mixed mesoporous Ag2O and AgO NW thin films. The Ag2O phase of silver oxide appears after 300 s of oxidation under the same conditions, while the optical transparency of the thin film decreases as plasma etching time increases. The sheet resistance of the final film is influenced by the oxidation time and the plasma application periodicity. Graphic abstract

Thin-film multiple-quantum-well solar cells fabricated by epitaxial lift-off process

2018 ◽  
Vol 57 (8S3) ◽  
pp. 08RF03 ◽  
Author(s):  
Tatsuya Nakata ◽  
Kentaroh Watanabe ◽  
Naoya Miyashita ◽  
Hassanet Sodabanlu ◽  
Maxime Giteau ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Quantum Well ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
Lift Off

Domain Structure of Epitaxial SrRuO3 Thin Films on (001) LaA1O3

1998 ◽  
Vol 4 (S2) ◽  
pp. 578-579
Author(s):  
J. C. Jiang ◽  
X.Q. Pan ◽  
Q. Gan ◽  
C. B. Eom
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Magnetic Properties ◽  
Cross Section ◽  
Ion Milling ◽  
Plan View ◽  
Face To Face ◽  
Electrical And Magnetic Properties ◽  
Device Applications ◽  
Ferroelectric Capacitors

Epitaxial thin film of SrRuO3 is very useful in device applications, due to its important electrical and magnetic properties. For example, (Pb,Zr)TiO3 ferroelectric capacitors with SrRuO3 thin film electrodes exhibit superior fatigue and leakage characteristics. Epitaxial SrRuO3 thin films grown on different substrates, such as on (001) SrTiO3 and (001) LaA1O3, have different magnetic properties, owing to the different microstructures in the film. Microstructures in epitaxial SrRuO3 thin films grown on (001) SrTiO3 have been studied in our previously work. In this paper, microstructure of epitaxial SrRu03 thin films grown on (001) LaA103 is reported.SrRuO3 thin films on (001) LaA1O3 were deposited by 90° off-axis sputtering. For cross-section TEM studies the SrRuO3/LaA1O3 heterostructural samples were cut along the [100] direction of LaA103. The cut slides were glued face-to-face by joining the SrRu03 surfaces. Plan-view and cross-section TEM specimens were prepared by mechanical grinding, polishing and dimpling, followed by Ar-ion milling.

Short-range order in amorphous co-sputtered Ta-Al thin films

1986 ◽  
Vol 44 ◽  
pp. 860-861
Author(s):  
J.C. Barry ◽  
R.S. Timsit ◽  
D. Landheer
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electron Microscope ◽  
High Resolution ◽  
Short Range ◽  
Short Range Order ◽  
Range Order ◽  
Transmission Electron ◽  
Thin Film Resistors ◽  
Diffraction Patterns

Tantalum-aluminium thin films have assumed considerable technological importance since the discovery in the late 1960's that the films are useful in the fabrication of thin film resistors and capacitors. It is generally claimed that these films, when prepared by co-sputtering Ta and Al, are amorphous over a range of Ta concentrations extending approximately from 15 to 75 at%, and are crystalline beyond this range. Diffuse electron diffraction patterns and ‘mottle pattern’ transmission electron micrographs are typical characteristics of the amorphous phase. In this present study we have attempted to identify any atomic short range order in the amorphous Ta-Al films and to follow the changes in this order as the Ta concentration increases across the amorphous/crystalline transition. The co-sputtered Ta-Al films of ≈100A thickness were examined in a high resolution 4000EX electron microscope (top entry, ±15°(x,y) tilt, Cs = 1.0mm ) at 400kV.

Analysis of the Properties of Tungsten Carbide Thin Films According to the Sputtering Radio Frequency Power

2020 ◽  
Vol 12 (10) ◽  
pp. 1568-1571
Author(s):  
Seokwon Lee ◽  
Jung Hyun Kim ◽  
Young Park ◽  
Wonseok Choi
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electron Microscope ◽  
Tungsten Carbide ◽  
Rf Magnetron Sputtering ◽  
Sem Analysis ◽  
Glass Substrates ◽  
Frequency Power ◽  
Scanning Electron ◽  
Sputtering System

In this study, we investigated characteristics of tungsten carbide thin film according to carbon and tungsten ratio. Tungsten carbide thin film was co-sputtered on silicon substrate and glass substrates using an RF magnetron sputtering system. To analyze the characteristics according to the composition ratio of the tungsten carbide thin film, the RF powers of carbon/tungsten target were divided into 100 W/100 W, 125 W/75 W, 150 W/50 W, and 175 W/25 W, respectively. Hall measurement and 4 points probes were used to measure electrical properties of the tungsten carbide thin films. Raman and field emission scanning electron microscope (FE-SEM) analysis were performed.

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