Interfacial Fracture Characterization of Nano-Scale Thin Films Using Single-Strip Stress-Engineered Superlayer

2006 ◽  
Author(s):  
Jiantao Zheng ◽  
Suresh K. Sitaraman
Keyword(s):  
Thin Films ◽  
Crack Propagation ◽  
Interfacial Crack ◽  
Interfacial Fracture ◽  
Critical Energy ◽  
Test Method ◽  
Nano Scale ◽  
Available Energy ◽  
Fracture Parameters

Characterization of interfacial fracture parameters for nano-scale thin films continues to be challenging due to the difficulties associated with preparing samples, fixturing and loading the samples, and extracting and analyzing the experimental data. In this paper, we propose a stress-engineered superlayer test method that can be used to measure the interfacial fracture parameters of nano-scale (as well as micro-scale) thin films without the need for loading fixtures. The proposed test employs the residual stress in sputter-deposited metals to provide the energy for interfacial crack propagation. The innovative aspect of the test is the use of an etchable release layer that is deposited between the two interfacial materials of interest. The release layer is designed such that the available energy for interfacial crack propagation will continue to decrease as the crack propagates, and at the location where the crack ceases to propagate, the available energy for crack propagation will be the critical energy for crack propagation or the interfacial fracture toughness. The proposed test method has been successfully used to characterize Ti thin film on Si substrate.

Single-Strip Decohesion Test to Characterize Nano-Scale Thin Film Delamination

2005 ◽  
Author(s):  
Jiantao Zheng ◽  
Suresh K. Sitaraman
Keyword(s):  
Thin Film ◽  
Fracture Toughness ◽  
Interfacial Fracture ◽  
Critical Energy ◽  
Test Method ◽  
Interfacial Fracture Toughness ◽  
Critical Energy Release Rate ◽  
Nano Scale ◽  
Thin Film Adhesion ◽  
Single Strip

A new test method, Single-Strip Decohesion Test (SSDT), has been developed and used to measure the interfacial fracture toughness of nano-scale thin film on substrate. This fixtureless test employs a stress-engineered superlayer deposited on patterned titanium (Ti) film strips to supply the energy for the delamination from a thick silicon (Si) substrate. The amount of energy available for delamination propagation is varied by fabricating an etchable thin release layer of varying width between the film strips and the substrate. By designing a decreasing area of the release layer, it is possible to arrest the delamination at a given location, and the interfacial fracture toughness or critical energy release rate can be found at the location where the delamination ceases to propagate. Common IC fabrication techniques are used to prepare the sample and execute the test, thereby making the test compatible with current microelectronic or MEMS facilities and suitable for in process measurement of thin film adhesion strength. The methodology presented in this paper is generic in nature, and can be used to measure the process-dependent interfacial fracture toughness of various micro-scale and nano-scale thin film interfaces. Ti thin film with thickness ranging from 5nm to 100nm can be studied using this method.

Study on Interfacial Crack Propagation and Fracture between Embedded Steel and HSHPC

2007 ◽  
Vol 348-349 ◽  
pp. 853-856
Author(s):  
Shan Suo Zheng ◽  
Lei Li ◽  
Guo Zhuan Deng ◽  
Liang Zhang
Keyword(s):  
Crack Propagation ◽  
High Performance ◽  
Fracture Process ◽  
Fracture Process Zone ◽  
High Performance Concrete ◽  
Process Zone ◽  
Interfacial Crack ◽  
High Strength ◽  
Interfacial Fracture ◽  
Softening Process

Steel reinforced high strength and high performance concrete (SRHSHPC) specimens were experimented to study the mechanical behaviors between steel and concrete interface. In experiment, interfacial bond softening process was observed, which can be explained in terms of damage along the interface, leading to progressive reduction of shear transfer capability between steel and high strength and high performance concrete (HSHPC). In this paper, bond softening process along the interface is considered in the analysis of crack-induced debonding. Interfacial bond-slip mechanism between steel and HSHPC is studied in detail based on fracture mechanics. With the help of acoustic emissions technology, the crack propagation in the interlayer was observed, thus the interfacial crack propagation and fracture model is set up. Under the assumption that the interlayer is weak concrete compared with concrete matrix, the stress field as well as displacement field around the crack tip is deduced. The characteristics of interfacial fracture process are discussed and a model for interfacial fracture process zone is built up. With this model, the size of fracture process zone can be derived. At last, the influence of the fracture process zone on interfacial fracture toughness is determined using critical fracture toughness. All these may contribute to improvement of theory for SRHSHPC composite structure.

scholarly journals Characterization of Nano-Scale Defects in Pulsed Laser Deposited (PLD) Thin Films of Li3xNd(2/3-x)(1/3-2x)TiO3 (NLTO) by Aberration Corrected HR-STEM Imaging and Dual-EELS

2020 ◽  
Vol 26 (S2) ◽  
pp. 3166-3167
Author(s):  
Robert Williams ◽  
Nuria Bagues ◽  
Elahe Farghadany ◽  
Alp Sehirlioglu ◽  
David McComb
Keyword(s):  
Thin Films ◽  
Pulsed Laser ◽  
Nano Scale ◽  
Aberration Corrected

Finite-Element-Simulation of Interfacial Crack Propagation: Cross-Check of Simulation Results with the Essential Work of Interfacial Fracture Method

2006 ◽  
Vol 312 ◽  
pp. 9-14 ◽  
Author(s):  
T. Schüller ◽  
B. Lauke
Keyword(s):  
Fracture Toughness ◽  
Finite Element ◽  
Crack Propagation ◽  
Data Reduction ◽  
Failure Process ◽  
Interfacial Crack ◽  
Interfacial Fracture ◽  
Essential Work ◽  
Strong Argument ◽  
Load Displacement

An advanced finite-element model for the complete failure process of a double notched specimen with crack tip blunting caused by yielding and subsequent crack propagation is used for the simulation of realistic specimens. Cracks in a homogeneous material and bimaterial cracks are studied. The calculated load-displacement curves show generally the shape known from experiments and theoretical considerations. The simulation allows determination of a working range of set up parameters like geometry, test speed or clamping conditions. The numerical model simulates crack propagation on the basis of a criterion which is similar to the energy release rate. The essential work of interfacial fracture method provides a method to determine the fracture toughness from load-displacement curves. This method is well suited to check the numerical simulation because both use an energy based failure criterion. If applied to simulated load-displacement curves the resulting essential work of interfacial fracture should directly match the fracture criterion used as input for the simulation. In fact, the data reduction of the simulated curves results in values for the fracture toughness that almost perfectly match the input values of the simulation. This agreement is a strong argument for the consistency of the simulation and the data reduction scheme.

MEMS Resonance Test for Mechanical Characterization of Nano-Scale Thin Films

2010 ◽  
Author(s):  
H. Yamagiwa ◽  
D. Goto ◽  
T. Namazu ◽  
T. Takeuchi ◽  
K. Murakami ◽  
...  
Keyword(s):  
Thin Films ◽  
Mechanical Characterization ◽  
Nano Scale ◽  
Resonance Test

Direct CTE Measurement Technique for the MEMS Materials

2006 ◽  
Vol 326-328 ◽  
pp. 199-202 ◽  
Author(s):  
Chung Seog Oh ◽  
Sung Hoon Choa ◽  
Chang Seung Lee ◽  
Hak Joo Lee
Keyword(s):  
Thin Films ◽  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion ◽  
Test System ◽  
Test Method ◽  
Linear Coefficient ◽  
Aln Film ◽  
Certified Value ◽  
Plane Displacement

The accurate characterization of linear coefficient of thermal expansion (CTE) of thin films is vital for predicting the thermal stress, which often results in warpage and failure of a MEMS structure. In this paper, special emphasis is placed on the development of novel test method to extend an ISDG (Interferometric Strain/Displacement Gage) technique to the direct and accurate CTE measurement of MEMS materials, AlN and Au. The freestanding AlN and Au films are 1 μm thick and 5 mm wide. Strain is directly measured by a brand-new digital type ISDG with two Cr lines deposited on the specimen while heating a specimen in a furnace. The whole test system is verified first by measuring the CTE for the NIST’s SRM (Standard Reference Material) 736 (Cu) block. The measured CTE is 17.3 με/oC up to 167 oC, which agrees well with the NIST’s certified value. The CTE of Au is 25.4 ± 1.15 με/oC and that of AlN film is 3.77 ± 0.12 με/oC. The in-plane displacement resolution is about 5 nm at the best circumstances.

Sign in / Sign up

Export Citation Format

Share Document