Stresses in Multilayered Thin Films on a Thick Substrate

1987 ◽  
Vol 91 ◽  
Author(s):  
E. Suhir
Keyword(s):  
Thin Films ◽  
Fatigue Strength ◽  
Structural Characteristics ◽  
Normal Stresses ◽  
Thermally Induced ◽  
Heteroepitaxial Structures ◽  
Thick Substrate ◽  
Induced Stresses ◽  
Multilayered Thin Films ◽  
Distribution Of Stresses

ABSTRACTThe analysis contains an engineering method for the prediction of thermally induced stresses in single- and multilayered heteroepitaxial structures on a thick substrate. The examined stresses include 1) normal stresses acting in the film layers themselves and responsible for their ultimate and fatigue strength, and 2) interfacial stresses responsible for film blistering and peeling. The developed formulas are simple, visible, easy-to-use, and clearly indicate how material and structural characteristics affect the magnitude and the distribution of stresses and deflections. Some recommendations for smaller stresses in film structures are presented. The obtained results can be utilized as a guidance for an optimal physical design of multilayered heteroepitaxial structures used in Microelectronics.

An Approximate Analysis of Stresses in Multilayered Elastic Thin Films

1988 ◽  
Vol 55 (1) ◽  
pp. 143-148 ◽  
Author(s):  
E. Suhir
Keyword(s):  
Thin Films ◽  
Structural Characteristics ◽  
Finite Size ◽  
Approximate Analysis ◽  
Normal Stresses ◽  
Approximate Evaluation ◽  
Thermally Induced ◽  
Heteroepitaxial Structures ◽  
Induced Stresses ◽  
Distribution Of Stresses

The analysis contains an engineering method for the approximate evaluation of thermally induced stresses in single and multilayered heteroepitaxial structures fabricated on thick substrates, with consideration of the finite size of the structure. The examined stresses include normal stresses, acting in the film layers themselves and responsible for their ultimate and fatigue strength, as well as interfacial stresses, responsible for film blistering and peeling. The developed formulas are simple, easy-to-use, and clearly indicate how material and structural characteristics affect the magnitude and the distribution of stresses and deflections. Some recommendations for smaller stresses in film structures are presented. The obtained results can be utilized as a guidance for physical design of multilayered heteroepitaxial structures in microelectronics.

Thermally induced structural characteristics of pentacene thin films

2009 ◽  
Vol 105 (11) ◽  
pp. 113520 ◽  
Author(s):  
Dong Guo ◽  
Susumu Ikeda ◽  
Koichiro Saiki
Keyword(s):  
Thin Films ◽  
Structural Characteristics ◽  
Thermally Induced

Thermally Induced Stresses in Passivated Thin Films and Patterned Lines of AlSiCu

1994 ◽  
Vol 338 ◽  
Author(s):  
U. Burges ◽  
H. Helneder ◽  
H. KÖrner ◽  
H. Schroeder ◽  
W. Schilling
Keyword(s):  
Thin Films ◽  
Stress Relaxation ◽  
Aspect Ratio ◽  
Thermal Cycling ◽  
High Temperatures ◽  
Room Temperature ◽  
Elastic Behaviour ◽  
Thermally Induced ◽  
Induced Stresses ◽  
Beam Technique

ABSTRACTA bending beam technique was used to measure the mechanical stresses in AlSi(l%)Cu(0.5%) blanket films as well as in patterned lines (aspect ratio: 0.8) - unpassivated and passivated with SiNx - during thermal cycling from –170°C or room temperature to 450°C.Main results are:a) No significant differences in unpassivated and passivated blanket films with thickness ranging from 0.2 µm to 3.2 µm.b) In unpassivated patterned lines of 0.8 µm thickness the stresses across the lines are very small, while parallel to the lines they show nearly elastic behaviour, except at high temperatures.c) In passivated patterned lines the stresses are much higher than in blanket films, very similar parallel and across the line and nearly elastic. The stress relaxation is small compared with blanket films and depends strongly on the temperature.

Morphologies of Nonadherent Al2O3 and Matching Substrate Surfaces

1972 ◽  
Vol 30 ◽  
pp. 524-525
Author(s):  
C. S. Giggins ◽  
J. K. Tien ◽  
B. H. Kear ◽  
F. S. Pettit
Keyword(s):  
Electron Microscopy ◽  
Oxide Scale ◽  
Oxidation Resistance ◽  
Substrate Surface ◽  
Morphological Features ◽  
Thermally Induced ◽  
Oxide Spallation ◽  
Oxidation Resistant ◽  
Induced Stresses ◽  
Substrate Surfaces

The performance of most oxidation resistant alloys and coatings is markedly improved if the oxide scale strongly adheres to the substrate surface. Consequently, in order to develop alloys and coatings with improved oxidation resistance, it has become necessary to determine the conditions that lead to spallation of oxides from the surfaces of alloys. In what follows, the morphological features of nonadherent Al2O3, and the substrate surfaces from which the Al2O3 has spalled, are presented and related to oxide spallation.The Al2O3, scales were developed by oxidizing Fe-25Cr-4Al (w/o) and Ni-rich Ni3 (Al,Ta) alloys in air at 1200°C. These scales spalled from their substrates upon cooling as a result of thermally induced stresses. The scales and the alloy substrate surfaces were then examined by scanning and replication electron microscopy.The Al2O3, scales from the Fe-Cr-Al contained filamentary protrusions at the oxide-gas interface, Fig. 1(a). In addition, nodules of oxide have been developed such that cavities were formed between the oxide and the substrate, Fig. 1(a).

Chromium multilayered thin films with orientated microstructure

2005 ◽  
Vol 123 ◽  
pp. 137-142 ◽  
Author(s):  
J. Takadoum ◽  
J. Lintymer ◽  
J. Gavoille ◽  
N. Martin
Keyword(s):  
Thin Films ◽  
Multilayered Thin Films

Optical and structural characteristics of electrodeposited Cd 1-xZnxS nanostructured thin films

2021 ◽  
Vol 114 ◽  
pp. 110966
Author(s):  
K. Erturk ◽  
M. Isik ◽  
M. Terlemezoglu ◽  
N.M. Gasanly
Keyword(s):  
Thin Films ◽  
Structural Characteristics ◽  
Nanostructured Thin Films

scholarly journals Effect of micro-notches on fatigue strength of electrodeposited nanocrystalline nickel thin films

2018 ◽  
Vol 165 ◽  
pp. 04011
Author(s):  
Keisuke Tanaka ◽  
Yuta Murase ◽  
Hirohisa Kimachi
Keyword(s):  
Thin Films ◽  
Fatigue Strength ◽  
Fatigue Limit ◽  
Stress Ratio ◽  
Fatigue Crack Initiation ◽  
Fatigue Tests ◽  
Fine Grained ◽  
Nickel Thin Films ◽  
Nano Crystalline ◽  
Fictitious Crack

The effect of micro-notches on the fatigue strength of nickel thin films was studied. Two types of thin films with 10 μm thickness were produced by electrodeposition using sulfamate solution without and with brightener: ultra-fine grained film (UFG) with the grain size of 384 nm and nano-crystalline grained film (NCG) with that of 17 nm. Micro-sized notches introduced by FIB had the width of 2 μm and various depths from 8 to 150μm. Fatigue tests were conducted under the stress ratio of 0.1. The fatigue strength decreased with increasing depth of notches. NCG had much higher strength than UFG compared at the same notch depth. Notches as small as 8μm did reduce the fatigue strength of both UFG and NCG. The fatigue limit was controlled by the initiation of cracks and no non-propagating crack was observed in specimens fatigued below the fatigue limit. A model of fictitious crack successfully predicted the reduction of the fatigue limit due to micro-notches. The characteristic crack length of NCG was much smaller than the UFG, while the fatigue strength of defect-free NCG was larger than that of UFG. SEM observation of fracture surfaces was conducted to reveal micromechanisms of fatigue crack initiation.

Synthesis of Nanocomposite thin film Ti/Al Multilayers and Ti-Aluminides

1996 ◽  
Vol 457 ◽  
Author(s):  
R. Banerjee ◽  
X. D. Zhang ◽  
S. A. Dregia ◽  
H. L. Fraser
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Magnetron Sputtering ◽  
Layer Thickness ◽  
Thermodynamic Model ◽  
Interfacial Reactions ◽  
Experimental Results ◽  
Structural Transitions ◽  
Nanocomposite Thin Film ◽  
Multilayered Thin Films

ABSTRACTNanocomposite Ti/Al multilayered thin films have been deposited by magnetron sputtering. These multilayers exhibit interesting structural transitions on reducing the layer thickness of both Ti and Al. Ti transforms from its bulk stable hep structure to fee and Al transforms from fee to hep. The effect of ratio of Ti layer thickness to Al layer thickness on the structural transitions has been investigated for a constant bilayer periodicity of 10 nm by considering three different multilayers: 7.5 nm Ti / 2.5 nm Al, 5 nm Ti / 5 nm Al and 2.5 nm Ti / 7.5 nm Al. The experimental results have been qualitatively explained on the basis of a thermodynamic model. Preliminary experimental results of interfacial reactions in Ti/Al bilayers resulting in the formation of Ti-aluminides are also presented in the paper.

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