Non-Contact Real-Time Evaluation of Polyimide Thin Film Thermoelastic Properties Through Impulsive Stimulated Thermal Scattering

1992 ◽  
Vol 284 ◽  
Author(s):  
J. A. Rogers ◽  
A. R. Duggal ◽  
K. A. Nelson

ABSTRACTWe demonstrate a new purely optical based method for the excitation and detection of acoustic and thermal disturbances in thin films. This technique is applied to the determination of the viscoelastic properties of unsupported and silicon supported polyimide thin (∼1 micron) films. We show how this technique can be used to detect film delaminations and suggest how it may be used to probe film-substrate adhesion quality.

2016 ◽  
Vol 4 (11) ◽  
pp. 2178-2186 ◽  
Author(s):  
Nusret S. Güldal ◽  
Thaer Kassar ◽  
Marvin Berlinghof ◽  
Tayebeh Ameri ◽  
Andres Osvet ◽  
...  

A portable in situ drying chamber, equipped with white light reflectometry, photoluminescence and light scattering, is used to fully characterize the thermodynamic and kinetic changes of P3HT- and DPP-TT-T-based organic bulk-heterojunction thin films during drying.


Author(s):  
D. R. Liu ◽  
S. S. Shinozaki ◽  
R. J. Baird

The epitaxially grown (GaAs)Ge thin film has been arousing much interest because it is one of metastable alloys of III-V compound semiconductors with germanium and a possible candidate in optoelectronic applications. It is important to be able to accurately determine the composition of the film, particularly whether or not the GaAs component is in stoichiometry, but x-ray energy dispersive analysis (EDS) cannot meet this need. The thickness of the film is usually about 0.5-1.5 μm. If Kα peaks are used for quantification, the accelerating voltage must be more than 10 kV in order for these peaks to be excited. Under this voltage, the generation depth of x-ray photons approaches 1 μm, as evidenced by a Monte Carlo simulation and actual x-ray intensity measurement as discussed below. If a lower voltage is used to reduce the generation depth, their L peaks have to be used. But these L peaks actually are merged as one big hump simply because the atomic numbers of these three elements are relatively small and close together, and the EDS energy resolution is limited.


Author(s):  
R. Rajesh ◽  
R. Droopad ◽  
C. H. Kuo ◽  
R. W. Carpenter ◽  
G. N. Maracas

Knowledge of material pseudodielectric functions at MBE growth temperatures is essential for achieving in-situ, real time growth control. This allows us to accurately monitor and control thicknesses of the layers during growth. Undesired effusion cell temperature fluctuations during growth can thus be compensated for in real-time by spectroscopic ellipsometry. The accuracy in determining pseudodielectric functions is increased if one does not require applying a structure model to correct for the presence of an unknown surface layer such as a native oxide. Performing these measurements in an MBE reactor on as-grown material gives us this advantage. Thus, a simple three phase model (vacuum/thin film/substrate) can be used to obtain thin film data without uncertainties arising from a surface oxide layer of unknown composition and temperature dependence.In this study, we obtain the pseudodielectric functions of MBE-grown AlAs from growth temperature (650°C) to room temperature (30°C). The profile of the wavelength-dependent function from the ellipsometry data indicated a rough surface after growth of 0.5 μm of AlAs at a substrate temperature of 600°C, which is typical for MBE-growth of GaAs.


Author(s):  
S. P. Sapers ◽  
R. Clark ◽  
P. Somerville

OCLI is a leading manufacturer of thin films for optical and thermal control applications. The determination of thin film and substrate topography can be a powerful way to obtain information for deposition process design and control, and about the final thin film device properties. At OCLI we use a scanning probe microscope (SPM) in the analytical lab to obtain qualitative and quantitative data about thin film and substrate surfaces for applications in production and research and development. This manufacturing environment requires a rapid response, and a large degree of flexibility, which poses special challenges for this emerging technology. The types of information the SPM provides can be broken into three categories:(1)Imaging of surface topography for visualization purposes, especially for samples that are not SEM compatible due to size or material constraints;(2)Examination of sample surface features to make physical measurements such as surface roughness, lateral feature spacing, grain size, and surface area;(3)Determination of physical properties such as surface compliance, i.e. “hardness”, surface frictional forces, surface electrical properties.


2006 ◽  
Vol 21 (2) ◽  
pp. 505-511 ◽  
Author(s):  
Lili Hu ◽  
Junlan Wang ◽  
Zijian Li ◽  
Shuang Li ◽  
Yushan Yan

Nanoporous silica zeolite thin films are promising candidates for future generation low-dielectric constant (low-k) materials. During the integration with metal interconnects, residual stresses resulting from the packaging processes may cause the low-k thin films to fracture or delaminate from the substrates. To achieve high-quality low-k zeolite thin films, it is important to carefully evaluate their adhesion performance. In this paper, a previously reported laser spallation technique is modified to investigate the interfacial adhesion of zeolite thin film-Si substrate interfaces fabricated using three different methods: spin-on, seeded growth, and in situ growth. The experimental results reported here show that seeded growth generates films with the highest measured adhesion strength (801 ± 68 MPa), followed by the in situ growth (324 ± 17 MPa), then by the spin-on (111 ± 29 MPa). The influence of the deposition method on film–substrate adhesion is discussed. This is the first time that the interfacial strength of zeolite thin films-Si substrates has been quantitatively evaluated. This paper is of great significance for the future applications of low-k zeolite thin film materials.


2011 ◽  
Vol 324 ◽  
pp. 93-96 ◽  
Author(s):  
Amel Gacem ◽  
A. Doghmane ◽  
Z. Hadjoub

The determination of the characteristics and properties of thin films deposited on substrates is necessary in any device application in various fields. Adequate mechanical properties are highly required for the majority of surface waves and semiconductor devices. In this context, modelling the ultrasonic-material interaction, we present results of simulation curves of acoustic signatures for multiple thin film/substrate combinations. The results obtained on several structures (Al, SiO2, ZnO, Cu, AlN, SiC and Cr)/(Al2O3, Si, Cu or Quartz) showed a velocity dispersion of the Rayleigh wave as a function of layer thickness. The development of a theoretical calculation model based on the acoustic behaviour of these structures has enabled us to quantify the dispersive evolution (positive and negative) density. Thus, we have established a universal relationship describing the density-thickness variation. In addition, networks of dispersion curves, representing the evolution of elasticity modulus (Young and shear), were determined. These charts can be used to extract the influence of thickness of layers on the variation of elastic constants


1999 ◽  
Vol 574 ◽  
Author(s):  
Norifumi Fujimura ◽  
Tamaki Shimura ◽  
Toshifumi Wakano ◽  
Atsushi Ashida ◽  
Taichiro Ito

AbstractWe propose the application of ZnO:X (X = Li, Mg, N, In, Al, Mn, Gd, Yb etc.) films for a monolithic Optical Integrated Circuit (OIC). Since ZnO exhibits excellent piezoelectric effect and has also electro-optic and nonlinear optic effects and the thin films are easily obtained, it has been studied as one of the important thin film wave guide materials especially for an acoustooptic device[1]. In terms of electro-optic and nonlinear optic effects, however, LiNbO3 or LiTaO3 is superior to ZnO. The most important issue of thin film waveguide using such ferroelectrics is optical losses at the film/substrate interface and the film surface, because the process window to control the surface morphology is very narrow due to their high deposition temperature. Since ZnO can be grown at extremely low temperature, the roughness at the surface and the interface is expected to be minimized. This is the absolute requirement especially for waveguide using a blue or ultraviolet laser. Recently, lasing at the wavelength of ultraviolet, ferroelectric and antiferromagnetic behaviors of ZnO doped with various exotic elements (exotic doping) have been reported. This paper discusses the OIC application of ZnO thin films doped with exotic elements.


1989 ◽  
Vol 169 ◽  
Author(s):  
K.M. Hubbard ◽  
P.N. Arendt ◽  
D.R. Brown ◽  
D.W. Cooke ◽  
N.E. Elliott ◽  
...  

AbstractThin films of the Tl‐based superconductors often have relatively poor properties because of film/substrate interdiffusion which occurs during the anneal. We have therefore investigated the use of BaF2 as a diffusion barrier. TICaBaCuO thin films were deposited by dc magnetron sputtering onto MgO <100> substrates, both with and without an evaporation‐deposited BaF2 buffer layer, and post‐annealed in a Tl over‐pressure. Electrical properties of the films were determined by four‐point probe analysis, and compositions were measured by ion‐backscattering spectroscopy. Structural analysis was performed by X‐ray diffraction and scanning electron microscopy. The BaF2 buffer layers were found to significantly improve the properties of the TICaBaCuO thin films.


1983 ◽  
Vol 29 (4) ◽  
pp. 645-649 ◽  
Author(s):  
M W Sundberg ◽  
R W Becker ◽  
T W Esders ◽  
J Figueras ◽  
C T Goodhue

Abstract We developed a thin-film enzymic assay for creatinine that makes use of creatinine iminohydrolase (EC 3.5.4.21) to convert creatinine to N-methylhydantoin and ammonia. The ammonia diffuses through a semipermeable layer and is quantitated by reaction with bromphenol blue. A paired analysis of the sample on a separate coating without the enzymic reaction measures endogenous ammonia and, for samples with normal concentrations of ammonia, allows accurate determination of serum creatinine to 150 mg/L without dilution. Results of this assay (y) compare well with those by a liquid-chromatographic comparison assay (x) by linear regression (slope = 0.935, intercept = 1.13 mg/L, r2 = 0.995). It is insensitive to many substances, such as ketones and keto acids, that interfere with conventional assays. Results of the ammonia assay (y) correlate well with those by a semi-automated enzymic assay (x) based on glutamate dehydrogenase (slope = 1.068, intercept = 17.3 mumol/L, r2 = 0.985).


2016 ◽  
Vol 1141 ◽  
pp. 51-53
Author(s):  
Chetan Zankat ◽  
V.M. Pathak ◽  
Pratik Pataniya ◽  
G.K. Solanki ◽  
K.D. Patel ◽  
...  

Amorphous SnSe thin films were deposited by thermal evaporation technique on glass substrates kept at room temperature in a vacuum better than 10-5Torr. A detailed study of structural and optical properties of 150 nm thin film was carried out. The selected area diffraction patterns obtained by TEM for this thin film were analyzed by a new method that involves accurate determination of lattice parameters by image processing software. The obtained results are in good agreement with the JCPDS data. Optical transmission spectra obtained at room temperature were analyzed to study optical properties of deposited thin films. It has been found that indirect carrier transition is responsible for optical absorption process in the deposited thin films.


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