Effects of substrate on determination of hardness of thin films by nanoscratch and nanoindentation techniques

2004 ◽  
Vol 19 (6) ◽  
pp. 1791-1802 ◽  
Author(s):  
Noureddine Tayebi ◽  
Andreas A. Polycarpou ◽  
Thomas F. Conry
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Elastic Recovery ◽  
Empirical Relationship ◽  
Residual Deformation ◽  
Substrate Effect ◽  
Nanoindentation Technique ◽  
Film Substrate ◽  
Composite Hardness

A comparative study on the effects of the substrate on the determination of hardness of thin films by the use of the nanoscratch and nanoindentation techniques was conducted. Gold films deposited on fused quartz substrates and silicon dioxide films deposited on aluminum substrates with variant film thicknesses were investigated. These two systems correspond to a soft film on a hard substrate and a hard film on a soft substrate, respectively. The effect of substrate interaction on the measurement of hardness using the nanoscratch technique was found to be less pronounced compared to that of the nanoindentation technique due to: (i) the lower normal loads applied to achieve the penetration depths that occur at higher loads when using the nanoindentation method; (ii) the direct imaging of the residual deformation profile that is used in the nanoscratch technique, which allows for the effects of pileup or sink-in to be taken into account, whereas in the nanoindentation technique the contact area is estimated from the load-displacement data, which does not include such effects; and (iii) the account of elastic recovery of the plastically deformed surfaces from scratch tests. The film thickness did not appear to have any effect on the hardness of Au and SiO2 films obtained from nanoscratch data. This observation allowed, for the case of SiO2 films, the determination of the “free substrate effect region” and the derivation of an empirical relationship that relates the composite hardness of the film/substrate system to the contact-depth-to-film-thickness ratio, even when the indenter penetrates into the substrate. Such findings can allow for the determination of the intrinsic hardness of ultrathin hard films (∼1–5 nm thick), where the substrate effect is unavoidable.

Effects of the substrate on the determination of hardness of thin films by the nanoscratch and nanoindentation techniques: A comparative study for the cases of soft film on hard substrate and hard film on soft substrate.

2003 ◽  
Vol 795 ◽  
Author(s):  
Noureddine Tayebi ◽  
Andreas A. Polycarpou ◽  
Thomas F. Conry
Keyword(s):  
Thin Films ◽  
Elastic Recovery ◽  
Hard Substrate ◽  
Substrate Effect ◽  
Soft Substrate ◽  
Substrate Interaction ◽  
Pile Up ◽  
Fused Quartz ◽  
Hardness Values

ABSTRACTHardness values of Au/Fused Quartz and SiO2/Al systems, which correspond to the cases of soft film on hard substrate and hard film on soft substrate, were measured using both the nanoindentation and nanoscratch techniques. The effect of substrate interaction on the measurement of hardness using the nanoscratch technique is found to be much less pronounced compared to that of the nanoindentation technique. Such reduction in substrate effect is attributed to the features used in the nanoscratch analysis: (a) direct imaging of residual profile allows for the effect of pile-up/sink-in to be considered, (b) lower normal loads applied as compared to the nanoindentation, (c) effect of elastic recovery of the plastically deformed surfaces is included in the nanoscratch analysis, whereas the nanoindentation analysis is based solely on the load-displacement data. Moreover, experiments with residual scratch depths as shallow as 3 nm are used to estimate hardness of thin films; a promising indication for the use of such technique in the measurements of ultra-thin films.

Quantification the Effect of the Thickness of Thin Films on their Elastic Parameters

2011 ◽  
Vol 324 ◽  
pp. 93-96 ◽  
Author(s):  
Amel Gacem ◽  
A. Doghmane ◽  
Z. Hadjoub
Keyword(s):  
Thin Films ◽  
Elasticity Modulus ◽  
Calculation Model ◽  
Thickness Variation ◽  
Acoustic Signatures ◽  
Context Modelling ◽  
Universal Relationship ◽  
Film Substrate ◽  
Material Interaction

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

Dependence of Resistivity on Thickness of Vacuum Deposited Copper Thin Films

2020 ◽  
Vol 12 (8) ◽  
pp. 1125-1129
Author(s):  
Shrutidhara Sarma
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Film Thickness ◽  
Empirical Relationship ◽  
Temperature Sensors ◽  
Vacuum Deposition ◽  
Deposition Chamber ◽  
Probe Technique ◽  
Film Resistivity ◽  
Electrical Systems

In depth understanding of resistivity of metals is of utmost importance for optimizing circuit designs and electrical systems. In this study, we investigated the relation between film thickness (in the range of 25−350 nm) and film resistivity of Cu thin films, with respect to thin film temperature sensors. The films were deposited in a vacuum deposition chamber over pyrex substrates and the film resistances were measured using 4 point probe technique. The empirical relationship established by Lacy has been used along with our experimental results in order to calculate the constants relating the filmsubstrate compatibility, which influences the change of resistivity with thickness.

scholarly journals Enhanced Ionic Conduction at the Film/Substrate Interface in LiI Thin Films Grown on Sapphire(0001)

1993 ◽  
Vol 318 ◽  
Author(s):  
D. Lubben ◽  
F. A. Modine
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Ionic Conduction ◽  
High Vacuum ◽  
Dislocation Motion ◽  
Ultra High Vacuum ◽  
Vacuum System ◽  
Substrate Interface ◽  
Interdigital Electrodes ◽  
Film Substrate

ABSTRACTThe ionic conductivity of LiI thin films grown on sapphire(0001) substrates has been studied in situ during deposition as a function of film thickness and deposition conditions. LiI films were produced at room temperature by sublimation in an ultra-high-vacuum system. The conductivity of the Lil parallel to the film/substrate interface was determined from frequency-dependent impedance measurements as a function of film thickness using Au interdigital electrodes deposited on the sapphire surface. The measurements show a conduction of ∼5 times the bulk value at the interface which gradually decreases as the film thickness is increased beyond 100 nm. This interfacial enhancement is not stable but anneals out with a characteristic log of time dependence. Fully annealed films have an activation energy for conduction (σT) of ∼0.47 ± .03 eV, consistent with bulk measurements. The observed annealing behavior can be fit with a model based on dislocation motion which implies that the increase in conduction near the interface is not due to the formation of a space-charge layer as previously reported but to defects generated during the growth process. This explanation is consistent with the behavior exhibited by CaF2 films grown under similar conditions.

Characterization of spray-pyrolized superconducting YBaCuO thin films on single-crystal MgO by transmission electron microscopy

1990 ◽  
Vol 5 (8) ◽  
pp. 1605-1611 ◽  
Author(s):  
S. J. Golden ◽  
H. Isotalo ◽  
M. Lanham ◽  
J. Mayer ◽  
F. F. Lange ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Film Thickness ◽  
Single Crystal ◽  
Processing Parameters ◽  
Transmission Electron ◽  
Film Substrate ◽  
Mgo Substrate

Superconducting YBaCuO thin films have been fabricated on single-crystal MgO by the spray-pyrolysis of nitrate precursors. The effects on the superconductive behavior of processing parameters such as time and temperature of heat treatment and film thickness were investigated. The superconductive behavior was found to be strongly dependent on film thickness. Films of thickness 1 μm were found to have a Tc of 67 K while thinner films showed appreciably degraded properties. Transmission electron microscopy studies have shown that the heat treatments necessary for the formation of the superconductive phase (for example, 950 °C for 30 min) also cause a substantial degree of film-substrate interdiffusion. Diffusion distances for Cu in the MgO substrate and Mg in the film were found to be sufficient to explain the degradation of the superconductive behavior in films of thickness 0.5 μm and 0.2 μm. From the concentration profiles obtained by EDS analysis diffusion coefficients at 950 °C for Mg into the YBaCuO thin film and for Cu into the MgO substrate were evaluated as 3 × 10−19 m2/s and 1 × 10−17 m2/s, respectively.

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
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Real Time ◽  
Viscoelastic Properties ◽  
Thermoelastic Properties ◽  
Substrate Adhesion ◽  
Thermal Scattering ◽  
Film Substrate ◽  
Time Evaluation

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.

A Finite Element Study on the Nanoindentation of Thin Films

2000 ◽  
Vol 649 ◽  
Author(s):  
Xi Chen ◽  
Joost J. Vlassak
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Finite Element ◽  
Film Thickness ◽  
Substrate Effect ◽  
The Finite Element Method ◽  
Effect Factor ◽  
Pile Up ◽  
Key Factor ◽  
Elastic Mismatch

ABSTRACTNanoindentation is a technique commonly used for measuring thin film mechanical properties such as hardness and stiffness. Typically, shallow indentations with contact depths less than 10-20% of the film thickness are used to ensure that measurements are not affected by the presence of the substrate. In this study, we have used the finite element method to investigate the effect of substrate and pile-up on hardness and stiffness measurements of thin film systems. We find that: i) for soft films on hard substrates, the hardness is independent of the substrate as long as the indentation depth is less than 50% of the film thickness; ii) as soon as the hardness exceeds that of the substrate, the substrate effect becomes significant, even for indentations as shallow as 5% of the film thickness; iii) if the film is at least 40 times harder than the substrate, the plastic zone is mostly confined to the substrate while the film conforms to the deformed substrate by bending. We define a substrate effect factor and construct a map that may be useful in the interpretation of indentation measurements on thin films. It is found that the yield stress mismatch is a key factor characterizing the hardness of thin film system, and the elastic mismatch is important when making stiffness measurements. The results obtained in this study are very useful when it is difficult to avoid the influence of the substrate on the measurements.

The Determination of Elemental Composition, Thickness and Crystalline Phases in Single and Multi-Layer Thin Films

1989 ◽  
Vol 33 ◽  
pp. 197-204
Author(s):  
R. A. Brown ◽  
K. Toda ◽  
R. L. Wilson
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Film Thickness ◽  
Elemental Composition ◽  
Crystalline Phases ◽  
Film Composition ◽  
Layer Thin Film

The purpose of this paper is to show how XRD and XRF can be used as complimentary tools to determine multi-layer thin film composition, both elemental and crystalline, as well as film thickness.

A Brittle to Ductile Transition (BDT) in Adhered Thin Films

1999 ◽  
Vol 594 ◽  
Author(s):  
W. W. Gerberich ◽  
A. A. Volinsky ◽  
N. I. Tymiak ◽  
N. R. Moody
Keyword(s):  
Thin Films ◽  
Energy Dissipation ◽  
Yield Strength ◽  
Plastic Zone ◽  
Film Thickness ◽  
Fracture Energy ◽  
Test Temperature ◽  
Plastic Energy ◽  
Order Of Magnitude ◽  
Film Substrate

AbstractIt has been long recognized that the BDT in bulk materials may be associated with enhanced plastic energy dissipation. This can be achieved by either changing the state of stress (plane strain to plane stress) or by raising the test temperature (lowering the yield stress). The situation is somewhat different in thin films where the BDT can be achieved by increasing film thickness or perhaps, even in a limited temperature range, by raising the test temperature. To study the latter we use a superlayer technique with a 1 μm tungsten film on top of thin copper films bonded to SiO2/Si wafers. This involves indenting into the superlayer which stores and then releases large amounts of elastic energy into the thin film/substrate interface. Here, preliminary data on 500 nm thick Cu demonstrates more than an order of magnitude increase in fracture energy from about 10 to 200 J/m2 as the test temperature is raised from 20°C to 130°C. As the amount of plastic energy absorption would appear to be limited by film thickness, this relatively large value was unanticipated. This interfacial fracture energy translates to a stress intensity of 5 MPa-m1/2. In context of the highest possible nanocrystalline Cu yield strength, this still represents a plastic zone of nearly 30 μm. This illustrates the quandary associated with explaining such high apparent toughness values as one generally expects plasticity to be truncated by film thickness. Is this associated with:–some artifact of assessing local stresses during nanoindentation at elevated temperature:–extending the plastic zone in the direction of crack growth much further than the film thickness;–a shielding mechanism from an organized dislocation array in a ductile film sandwiched between a brittle substrate and a higher yield strength superlayer;–some plastic energy dissipation in the superlayer;–or by enhanced mode II at higher temperatures?A few of these will be addressed in some detail with a goal of narrowing the field of the most promising candidates.

Sign in / Sign up

Export Citation Format

Share Document