Thermal Grooving in Single versus Multilayer Thin Films

2004 ◽  
Vol 854 ◽  
Author(s):  
Peter M. Anderson ◽  
Jue Wang ◽  
Sridhar Narayanaswamy

ABSTRACTA 2D analytic result is presented for the penetration distance P of grain boundary grooves as a function of time t during heating and straining of polycrystalline multilayer thin films with immiscible phases. These grooves can ultimately pinch off individual layers. The result shows that P ∼ t0.25 initially and P ∼ t at longer time. This new analysis contrasts single- versus multilayer thin film response.

2010 ◽  
Vol 11 ◽  
pp. 1-6 ◽  
Author(s):  
Sujira Promnimit ◽  
Joydeep Dutta

In this work, we report the directed self organization of multilayer thin film devices with colloidal nanoparticles through Layer-by-Layer (LbL) technique [1]. Self-organization of nanoparticles into assemblies to create novel nanostructures is getting increasing research attention in microelectronics, medical, energy and environmental applications. Directed self-organization of nanoparticles [2] into multilayer thin films were achieved by LbL growth through the interaction of oppositely charged of colloidal nanoparticles on substrates of any kind and shapes. Multilayer thin film devices were fabricated using multilayers of gold (conducting) nanoparticles separated by a dielectric nanoparticulate layer of zinc sulphide. The thin films obtained have been studied extensively and the changes in surface morphology, the optical absorption characteristics, thickness, uniformity, adhesion, and conduction behavior are reported. Current voltage (I-V) characteristics of multilayer devices with an increasing number of deposition cycles show an initial current blockade until an onset voltage value, which increases linearly upon the additional layers stacked in devices [3]. A conductive behavior of the device was observed upon exceeding the onset voltage. Moreover, I-V behavior showed that the conduction onset voltage increases linearly depending on the numbers of layers in the final device controlled by the deposition cycles. Systematic I-V characteristics in the forward and reverse biased conditions demonstrated rectifying behaviors in the onset of conduction voltage which makes these films attractive for future electronic device applications.


1991 ◽  
Vol 230 ◽  
Author(s):  
Katayun Barmak ◽  
Kevin R. Coffey ◽  
David A. Rudman ◽  
Simon Foner

AbstractWe investigated the phase formation sequence in the reaction of multilayer thin films of Nb/Al with overall compositions of 25 and 33 at.% AI. We report novel phenomena which distinguish thin-film reactions unequivocally from those in bulk systems. For sufficiently thin layers composition and stability of product phases are found to deviate significantly from that predicted from the equilibrium phase diagram. We demonstrate that in the Nb/Al system the length scales below which such deviations occur is about 150 nm. We believe that these phenomena occur due to the importance of grain boundary diffusion and hence microstructure in these thin films.


Author(s):  
K. Barmak

Generally, processing of thin films involves several annealing steps in addition to the deposition step. During the annealing steps, diffusion, transformations and reactions take place. In this paper, examples of the use of TEM and AEM for ex situ and in situ studies of reactions and phase transformations in thin films will be presented.The ex situ studies were carried out on Nb/Al multilayer thin films annealed to different stages of reaction. Figure 1 shows a multilayer with dNb = 383 and dAl = 117 nm annealed at 750°C for 4 hours. As can be seen in the micrograph, there are four phases, Nb/Nb3-xAl/Nb2-xAl/NbAl3, present in the film at this stage of the reaction. The composition of each of the four regions marked 1-4 was obtained by EDX analysis. The absolute concentration in each region could not be determined due to the lack of thickness and geometry parameters that were required to make the necessary absorption and fluorescence corrections.


2021 ◽  
Vol 8 ◽  
Author(s):  
Jinyu Ruan ◽  
Chao Yin ◽  
Tiandong Zhang ◽  
Hao Pan

Ferroelectric multilayer films attract great attention for a wide variation of applications. The synergistic effect by combining different functional layers induces distinctive electrical properties. In this study, ferroelectric BaZr0.2Ti0.8O3/PbZr0.52Ti0.48O3/BaZr0.2Ti0.8O3 (BZT/PZT/BZT) multilayer thin films are designed and fabricated by using the magnetron sputtering method, and a LaNiO3 (LNO) seed layer is introduced. The microstructures and electrical properties of the BZT/PZT/BZT films with and without the LNO seed layer are systematically studied. The results show that the BZT/PZT/BZT/LNO thin film exhibits much lower surface roughness and a preferred (100)-orientation growth, with the growth template and tensile stress provided by the LNO layer. Moreover, an enhanced dielectric constant, decreased dielectric loss, and improved ferroelectric properties are achieved in BZT/PZT/BZT/LNO thin films. This work reveals that the seed layer can play an important role in improving the microstructure and properties of ferroelectric multilayer films.


2016 ◽  
Vol 102 ◽  
pp. 364-372 ◽  
Author(s):  
Shang-Chun Lin ◽  
Ming-Wei Liu ◽  
Mogadalai P. Gururajan ◽  
Kuo-An Wu

1991 ◽  
Vol 238 ◽  
Author(s):  
M. Tan ◽  
E. Haftek ◽  
A. Waknis ◽  
J. A. Barnard

ABSTRACTThe electrical resistivity and crystal structure of three Ni-based periodic multilayer thin film systems (Al/Ni, Ti/Ni, and Cu/Ni) have been investigated. In each series of films the Ni layer thickness was systematically varied while the thickness of the ‘spacer’ layer (Al, Ti, or Cu) was fixed. In the Al/Ni and Ti/Ni systems films with very thin Ni layers (and consequently large volume fractions of spacer and ‘interfacial’ material) yielded very high resistivities which dropped rapidly with increasing Ni thickness. By contrast, the resistivity of Cu/Ni multilayers continuously increased with Ni layer thickness due to the decline in volume fraction of high conductivity Cu. Both the Al/Ni and Ti/Ni systems exhibit Ni(111) texture in the thicker Ni layer samples. As the Ni layer thickness decreases the Ni(111) peak loses intensity and broadens due to finer grain size and increasing disorder. Al-Ni and Ti-Ni compounds are also noted. In the Cu/Ni system, however, the sharpness of the Ni(111) peak passes through a minimum as the Ni layer thickness decreases but then increases for the thinnest Ni layer samples.


2021 ◽  
Author(s):  
Sungwook Mhin ◽  
Junho Lee ◽  
Deahyeon Ko ◽  
Kyoung Ryeol Park ◽  
Dongwon Kim ◽  
...  

Abstract Thin film-based optical sensors have been attracting increasing interest for use in developing technologies such as biometrics. Multilayered dielectric thin films with different refractive indices have been utilized to modulate the optical properties in specific wavelength bands for spectral selectivity of Thin Film Narrow Bandpass Filters (TFNBFs). Progress in TFNBF design has been made with the incorporation of metallic thin films. Narrower bandwidths with higher transmittance have been achieved in specific spectral bands. In this work, Ti/TiO2/SiO2 based multilayer thin films were prepared using pulsed-DC reactive sputtering. Computer simulations using the Essential Macleod Program allowed the optimal number of layers and thickness of the multilayer thin films to be determined to efficiently tailor the optical path transmitting specific wavelength bands. The addition of Ti metal layers within dielectric (TiO2/SiO2) multilayer thin films significantly changes the cutoff frequency of transmittance at specific wavelengths. Representative 26 multilayer films consisting of Ti, TiO2, and SiO2 show lower transmittance of 10.29 % at 400 nm and 10.48 % at 680 nm. High transmittance of 80.42 % at 485 nm was observed, which is expected to improve the spectral selectivity of the TFNBF. This work provides a contribution to future simulation based design strategy based on experimental thin film engineering for potential industrial development opportunities such as optical biometrics.


2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Dongju Kim ◽  
Kang Min Kim ◽  
Hyuksu Han ◽  
Junho Lee ◽  
Deahyeon Ko ◽  
...  

AbstractThin film-based optical sensors have been attracting increasing interest for use in developing technologies such as biometrics. Multilayered dielectric thin films with different refractive indices have been utilized to modulate the optical properties in specific wavelength bands for spectral selectivity of Thin Film Narrow Bandpass Filters (TFNBFs). Progress in TFNBF design has been made with the incorporation of metallic thin films. Narrower bandwidths with higher transmittance have been achieved in specific spectral bands. In this work, Ti/TiO2/SiO2 based multilayer thin films were prepared using pulsed-DC reactive sputtering. Computer simulations using the Essential Macleod Program allowed the optimal number of layers and thickness of the multilayer thin films to be determined to efficiently tailor the optical path transmitting specific wavelength bands. The addition of Ti metal layers within dielectric (TiO2/SiO2) multilayer thin films significantly changes the cutoff frequency of transmittance at specific wavelengths. Representative 26 multilayer films consisting of Ti, TiO2, and SiO2 show lower transmittance of 10.29% at 400 nm and 10.48% at 680 nm. High transmittance of 80.42% at 485 nm was observed, which is expected to improve the spectral selectivity of the TFNBF. This work provides a contribution to future simulation based design strategy based on experimental thin film engineering for potential industrial development opportunities such as optical biometrics.


1995 ◽  
Vol 413 ◽  
Author(s):  
Dongsik Yoo ◽  
Jin-kyu Lee ◽  
M. F. Rubner

ABSTRACTThe layer-by-layer self-assembly of a number of different functional dye molecules has been accomplished via the alternate spontaneous adsorption of polyelectrolytes and ionic dyes from dilute solutions. Multilayer thin films containing such functional dyes as pH indicator dyes, infrared absorbing dyes, porphyrin dyes and various fluorescent dyes have been successfully fabricated and their electrical and opt, 2al properties examined. Multilayers containing a newly synthesized ionic ruthenium based polypryidyl dye have been utilized to fabricate light emitting thin film devices with high brightness (ca. 100 cd/m2) at voltages in the range of 5–10 volts. These new light emitting thin film devices exhibit excellent stability when compared to devices based on conjugated polymers such PPV. The fabrication and device evaluation of new heterostructure thin films based on this new light emitting dye as well as the properties of other multilayer thin films containing dye molecules are presented.


RSC Advances ◽  
2015 ◽  
Vol 5 (64) ◽  
pp. 51891-51899 ◽  
Author(s):  
Meiyu Gai ◽  
Johannes Frueh ◽  
Agnes Girard-Egrot ◽  
Samuel Rebaud ◽  
Bastien Doumeche ◽  
...  

A theory and method for calculating printing resolution limits for microcontact printing of a condensed polyelectrolyte multilayer thin film, based on surface energies and line tension is presented.


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