Application of Nanoindentation to Characterize Fracture in ILD Films Used in the BEOL.

2005 ◽  
Vol 863 ◽  
Author(s):  
Eva E. Simonyi ◽  
E. Liniger ◽  
M. Lane ◽  
Q. Lin ◽  
C. D. Dimitrakopoulos ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Film Thickness ◽  
Low Dielectric Constant ◽  
Cracking Behavior ◽  
Low Dielectric ◽  
Afm Imaging ◽  
Low Modulus ◽  
Critical Film Thickness ◽  
Point Bend ◽  
Cohesive Energies

AbstractIt is of importance to understand cracking behavior in low dielectric constant, low modulus materials. Nanoindentation method is presented as a tool to estimate the critical film thickness, thickness above which spontaneous cracking could occur, for ILD films used in the BEOL. The critical film thickness was then used to calculate cohesive energies and fracture toughness of the films. Materials were investigated using nanoindentation combined with AFM imaging. The results were compared to data acquired by four point bend methods.

Comparison of the Fracture Behavior of Brittle ILD Films used in the BEOL in Dry and Wet Environment using Nanoindentation

2006 ◽  
Vol 914 ◽  
Author(s):  
Eva Simonyi ◽  
Michael Lane ◽  
Erik Liniger ◽  
Alfred Grill
Keyword(s):  
Fracture Toughness ◽  
Film Thickness ◽  
Manufacturing Process ◽  
Fracture Behavior ◽  
Imaging Methods ◽  
Afm Imaging ◽  
Critical Film Thickness ◽  
Low K

AbstractDuring the manufacturing process of the BEOL the low-k brittle ILD dielectrics are exposed to wet environments. These environments could and do affect the films fracture toughness, the so called critical film thickness, above which spontaneous cracking occurs. Nanoindentation combined with AFM imaging methods allow to study these phenomena.

Indentation fracture of low-dielectric constant films: Part II. Indentation fracture mechanics model

2008 ◽  
Vol 23 (9) ◽  
pp. 2443-2457 ◽  
Author(s):  
Dylan J. Morris ◽  
Robert F. Cook
Keyword(s):  
Dielectric Constant ◽  
Film Thickness ◽  
Film Stress ◽  
Low Dielectric Constant ◽  
Silicon Substrates ◽  
Instrumented Indentation ◽  
Indentation Fracture ◽  
Low Dielectric ◽  
Mechanics Model ◽  
Critical Film Thickness

Part I [D.J. Morris and R.F. Cook,J. Mater. Res.23,2429 (2008)] of this two-part work explored the instrumented indentation and fracture phenomena of compliant, low-dielectric constant (low-κ) films on silicon substrates. The effect of film thickness and probe acuity on the fracture response, as well as the apparent connection of this response to the perceived elastic modulus, were demonstrated. These results motivate the creation of a fracture model that incorporates all of these variables here in Part II. Indentation wedging is identified as the mechanism that drives radial fracture, and a correction is introduced that adjusts the wedging strength of the probe for the attenuating influence of the relatively stiff substrate. An estimate of the film fracture toughness can be made if there is an independent measurement of the film stress; if not, a critical film thickness for channel-cracking under the influence of film stress may be estimated.

Crosslinking and Ciiain-Scission of Photosensitive Polyimidesiloxane Under Deep UV Irradiation

1990 ◽  
Vol 203 ◽  
Author(s):  
S. Jeng ◽  
M. Xu ◽  
H. S. Kwok ◽  
D. Y. Tang ◽  
H. R. Acharya ◽  
...  
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Plasma Etching ◽  
Chain Scission ◽  
Low Dielectric Constant ◽  
Contact Mode ◽  
Low Dielectric ◽  
Oxygen Plasma Etching ◽  
Multi Level ◽  
193 Nm

ABSTRACTPolyimides are considered as promising packaging materials in multi-layer interconnections and multi-chip modules because of their low dielectric constant and good planarizability. Photosensitive polyimidesiloxane (SIM2000XL) as a newly emerging polyimide is showing not only similar properties as conventional polyimides but also the advantages of process simplification and improved adhesion. Moreover, it is proposed that SIM2000XL can be an oxygen-plasma etching barrier in multi-level lithographic systems because of its high silicon content.We characterized the photosensitivity of SIM2000XL thin films under excimer laser (193 nm) exposure. The sensitivity of SIM2000XL was found to be about 20 mJ/cm2. After the SIM2000XL thin films were exposed through a photomask in the contact mode, development gave the usual negative patterns. However, the remained film thickness after exposure reached a maximum of about 65 % of the initial film thickness and decreased with further irradiation. This can be attributed to the competing processes of polymer crosslinkage and chain-scission. This phenomenon is important for applications of polymers in DUV lithography. A detailed study of these two competing processes are presented.

Indentation Fracture Toughness Measurements of Low Dielectric Constant Materials

2003 ◽  
Vol 766 ◽  
Author(s):  
Dylan J. Morris ◽  
Robert F. Cook
Keyword(s):  
Fracture Toughness ◽  
Film Thickness ◽  
Scaling Laws ◽  
Film Stress ◽  
Low Dielectric ◽  
Fracture Toughness Measurement ◽  
Cube Corner ◽  
Simple Scaling ◽  
Low Dielectric Constant Materials ◽  
Low K

AbstractThe physics and mechanics of a fracture toughness measurement technique for low-k films are described. It has been observed experimentally that it is possible to generate reproducible stable cracks at indentation sites in thin low-k films using cube-corner indentation. The fracture response depends on the film thickness and follows no simple scaling laws. The physics of a model that takes into account the stress fields from indentation and film stress, with particular attention paid to the Poisson's ratio of the film, are described. The model is able to predict the changes in observables when the film thickness is changed, which allows one to estimate film toughness independent of the configuration of the material.

The Use of the Four-Point Bending Technique for Determining the Strength of Low K Dielectric/Barrier Interface

2000 ◽  
Vol 612 ◽  
Author(s):  
Ting Tsui ◽  
Cindy Goldberg ◽  
Greg Braeckelman ◽  
Stan Filipiak ◽  
Bradley M. Ekstrom ◽  
...  
Keyword(s):  
Low Dielectric Constant ◽  
Chemical Compositions ◽  
Adhesion Properties ◽  
Low Dielectric ◽  
Four Point Bending ◽  
Barrier Metal ◽  
Point Bend ◽  
Degraded Adhesion ◽  
Low K ◽  
Secondary Ion

AbstractOne of the important reliability challenges in integrating copper/Low-K dielectric technology has been adhesion between the Low-K dielectric and barrier metal. This investigation explored the applicability of the four-point bend technique for determining the adhesion strength of a fluorine doped low dielectric constant oxide in contact with tantalum barrier layer. Time of flight secondary ion mass spectroscopy (ToFSIMS) was used for surface chemical analyses of the delaminated surfaces to identify the fractured interface and its chemical compositions. The effect of annealing on mechanical strength was coupled with chemical analysis to discern the adhesion properties. Experimental results suggested that fluorine rich interfacial layer formation was associated with degraded adhesion characteristics between Low-K dielectric and tantalum barrier metal.

Effects of Curing Temperature on the Mechanical Reliability of Low Dielectric-Constant Spin-on-Glasses

2000 ◽  
Vol 612 ◽  
Author(s):  
Yvete Toivola ◽  
Robert F. Cook ◽  
Chandan Saha
Keyword(s):  
Dielectric Constant ◽  
High Stress ◽  
Curing Temperature ◽  
Low Dielectric Constant ◽  
Mechanical Reliability ◽  
High Modulus ◽  
Capacitance Measurements ◽  
Low Dielectric ◽  
Low Modulus ◽  
Film Dielectric

AbstractThe variations in the mechanical properties of a commercial low-k silsesquioxane material with curing temperature are examined, focusing on the transition from the low modulus, high stress, under-cured state to the high modulus, low stress, over-cured state. Film modulus and hardness are determined by instrumented nanoindentation and film dielectric constant is determined by ac capacitance measurements of metal dot structures. The mechanical behavior is correlated with changes in molecular structure via infrared spectroscopy. An implication of the results is that there is an intermediate curing temperature for optimum silsesquioxane interconnection performance.

scholarly journals Debye-Hückel Free Energy of an Electric Double Layer with Discrete Charges Located at a Dielectric Interface

Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 129
Author(s):  
Guilherme Volpe Bossa ◽  
Sylvio May
Keyword(s):  
Free Energy ◽  
Double Layer ◽  
Electric Double Layer ◽  
Low Dielectric Constant ◽  
Surface Charges ◽  
Dielectric Interface ◽  
Charge Densities ◽  
Low Dielectric ◽  
Poisson Boltzmann ◽  
The Continuum

Poisson–Boltzmann theory provides an established framework to calculate properties and free energies of an electric double layer, especially for simple geometries and interfaces that carry continuous charge densities. At sufficiently small length scales, however, the discreteness of the surface charges cannot be neglected. We consider a planar dielectric interface that separates a salt-containing aqueous phase from a medium of low dielectric constant and carries discrete surface charges of fixed density. Within the linear Debye-Hückel limit of Poisson–Boltzmann theory, we calculate the surface potential inside a Wigner–Seitz cell that is produced by all surface charges outside the cell using a Fourier-Bessel series and a Hankel transformation. From the surface potential, we obtain the Debye-Hückel free energy of the electric double layer, which we compare with the corresponding expression in the continuum limit. Differences arise for sufficiently small charge densities, where we show that the dominating interaction is dipolar, arising from the dipoles formed by the surface charges and associated counterions. This interaction propagates through the medium of a low dielectric constant and alters the continuum power of two dependence of the free energy on the surface charge density to a power of 2.5 law.

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