Buckling instabilities of thin cap layers deposited onto low-k dielectric films

2002 ◽  
Vol 734 ◽  
Author(s):  
F. Iacopi ◽  
S.H. Brongersma ◽  
T.J. Abell ◽  
K. Maex
Keyword(s):  
Dielectric Films ◽  
Dielectric Substrates ◽  
Low Dielectric ◽  
Film Adhesive ◽  
Compressive Stresses ◽  
Film Adhesion ◽  
Low Elastic Modulus ◽  
Adhesive Energy ◽  
Low K ◽  
Poor Adhesion

ABSTRACTCompressive stresses in thin capping films deposited onto low-k dielectric substrates are particularly prone to relaxation through buckling. This is due to insufficient cap/low-k film adhesion energy and to the compliance of low dielectric constant films. Low-k dielectric films, especially when porous, have low elastic modulus and demonstrate poor adhesion to other layers.When adhesion is poor the cap film can locally buckle as if unconstrained. The buckle front can propagate like a crack and lead to complete delamination of the cap layer. If the cap/low-k film adhesive energy is high, wrinkling instabilities can take place under specific conditions determined by the geometry and the mechanical properties of the stack. In this case the dielectric also deforms due to stress relaxation. A theoretical and experimental evaluation of the parameters influencing the occurrence of these instabilities is presented. This study was carried out to explore the application and reliability of low-k materials as dielectrics for advanced interconnects.

The characterization and preparation of porous low dielectric films using various cyclodextrins as template materials

2003 ◽  
Vol 766 ◽  
Author(s):  
Jin-Heong Yim ◽  
Jung-Bae Kim ◽  
Hyun-Dam Jeong ◽  
Yi-Yeoul Lyu ◽  
Sang Kook Mah ◽  
...  
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Dielectric Constant ◽  
Pore Structure ◽  
Pore Diameter ◽  
Dielectric Films ◽  
Low Dielectric Constant ◽  
Cyclodextrin Derivatives ◽  
Low Dielectric ◽  
Low K

AbstractPorous low dielectric films containing nano pores (∼20Å) with low dielectric constant (<2.2), have been prepared by using various kinds of cyclodextrin derivatives as porogenic materials. The pore structure such as pore size and interconnectivity can be controlled by changing functional groups of the cyclodextrin derivatives. We found that mechanical properties of porous low-k thin film prepared with mCSSQ (modified cyclic silsesquioxane) precursor and cyclodextrin derivatives were correlated with the pore interconnection length. The longer the interconnection length of nanopores in the thin film, the worse the mechanical properties of the thin film (such as hardness and modulus) even though the pore diameter of the films were microporous (∼2nm).

scholarly journals Electrical and Reliability Characteristics of Self-Forming Barrier for CuNd/SiOCH Films in Cu Interconnects

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 155
Author(s):  
Yi-Lung Cheng ◽  
Chih-Yen Lee ◽  
Wei-Fan Peng ◽  
Giin-Shan Chen ◽  
Jau-Shiung Fang
Keyword(s):  
Dielectric Film ◽  
Alloy Film ◽  
Dielectric Films ◽  
Low Dielectric Constant ◽  
Electrical Characteristics ◽  
Sputtering Deposition ◽  
Cu Interconnects ◽  
Low Dielectric ◽  
Reliability Characteristics ◽  
Low K

In this study, Cu-2.2 at. % Nd alloy films using a co-sputtering deposition method were directly deposited onto porous low-dielectric-constant (low-k) films (SiOCH). The effects of CuNd alloy film on the electrical properties and reliability of porous low-k dielectric films were studied. The electrical characteristics and reliability of the porous low-k dielectric film with CuNd alloy film were enhanced by annealing at 425 °C. The formation of self-forming barrier at the CuNd/SiOCH interface was responsible for this improvement. Therefore, integration with CuNd and porous low-k dielectric is a promising process for advanced Cu interconnects.

Adhesion Energy Measurements of Multilayer Low-K Dielectric Materials for ULSI Applications

1998 ◽  
Vol 511 ◽  
Author(s):  
E. O. Shaffer ◽  
M. E. Mills ◽  
D. Hawn ◽  
M. Van Gestel ◽  
A. Knorr ◽  
...  
Keyword(s):  
Surface Analysis ◽  
Critical Dimension ◽  
Dielectric Materials ◽  
Low Dielectric Constant ◽  
New Materials ◽  
Low Dielectric ◽  
Processing Strategies ◽  
Mechanical Adhesion ◽  
Low K ◽  
Poor Adhesion

ABSTRACTCurrently, the IC industry is researching the integration of a variety of materials to meet the low dielectric constant requirement for improved back-end of line (BEOL) interconnect performance. One critical dimension for successful ntegration of these new materials is maintaining mechanical integrity through multilayer processes. This includes both cohesive and adhesive fracture resistance. The latter adds additional complexity in that adhesive toughness is a function of the adherend materials and the processes used to join them. Hence, many good dielectric materials may be rematurely eliminated from further research not because of inherently poor adhesion but because of the necessity to optimize processing strategies.In this paper, we use the modified Edge Liftoff Test (m-ELT) to quantify the mechanical adhesion of multilayer blanket coatings. A specific example is used to demonstrate the utility of combining the m-ELT with surface analysis to optimize the reliability of low-K dielectric resins for use in ULSI applications. The system studied consists of a Cyclotene™ 5021(BCB) low-K material integrated with CVD aluminum for single level, damascene structures. The effects of liner layer metallurgy and surface plasma treatments are measured. Surface analysis is done on the failed parts to understand the location of the failure. In this way recommendations for process optimization can be made.

Solvent diffusion in porous low-k dielectric films

2003 ◽  
Vol 766 ◽  
Author(s):  
Denis Shamiryan ◽  
Karen Maex
Keyword(s):  
Dielectric Constant ◽  
Diffusion Coefficient ◽  
Porous Matrix ◽  
Silicon Oxycarbide ◽  
Dielectric Films ◽  
Polar Solvents ◽  
Low Dielectric ◽  
The Difference ◽  
Low K ◽  
And Diffusion

AbstractPorous materials are being investigated as low dielectric constant (low-k) materials. While porosity decreases the k-value of a material by decreasing its density, it simultaneously allows unwanted adsorption and diffusion of chemicals inside the porous matrix. To investigate this, different porous low-k materials, specifically silicon oxycarbide (SiOCH), methylsilsesquioxane (MSQ), and a polymer, were exposed to polar (ethanol) and non-polar (toluene) solvents. A difference in diffusion of polar and non-polar solvents would be an indication of the density of polar centers which attract polar molecules (such as water) and increase the dielectric constant of a film. The diffusion coefficient for toluene at room temperature was found to be approximately 2×10-5 cm2/sec for MSQ (40% porosity), 10-7 cm2/sec for SiOCH (7% porosity), 2×10-8 cm2/sec for the polymer. The observed diffusion can be described by a model of a viscous flow in a porous medium. The toluene/ethanol diffusion coefficient ratios were 4.4, 1.3, 1 for MSQ, SiOCH, and the polymer, respectively. The difference in toluene/ethanol diffusion can potentially be used to screen a material's affinity for water adsorption.

Precision Xe Plasma FIB Delayering for Physical Failure Analysis of Sub-20 nm Microprocessor Devices

2017 ◽  
Author(s):  
D. Zudhistira ◽  
V. Viswanathan ◽  
V. Narang ◽  
J.M. Chin ◽  
S. Sharang ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Dielectric Films ◽  
Planar Surface ◽  
Chemical Methods ◽  
Root Cause ◽  
Essential Step ◽  
Dielectric Layers ◽  
Wet Chemical ◽  
20 Nm ◽  
Low K

Abstract Deprocessing is an essential step in the physical failure analysis of ICs. Typically, this is accomplished by techniques such as wet chemical methods, RIE, and mechanical manual polishing. Manual polishing suffers from highly non-uniform delayering particularly for sub 20nm technologies due to aggressive back-end-of-line scaling and porous ultra low-k dielectric films. Recently gas assisted Xe plasma FIB has demonstrated uniform delayering of the metal and dielectric layers, achieving a planar surface of heterogeneous materials. In this paper, the successful application of this technique to delayer sub-20 nm microprocessor chips with real defects to root cause the failure is presented.

Finite-Element Modeling and Quantitative Measurement Using Scanning Microwave Microscopy to Characterize Dielectric Films

2018 ◽  
Author(s):  
K. A. Rubin ◽  
W. Jolley ◽  
Y. Yang
Keyword(s):  
Thin Films ◽  
Dielectric Film ◽  
Dielectric Constants ◽  
Dielectric Films ◽  
Silicon Substrates ◽  
Fem Modeling ◽  
Dielectric Thin Films ◽  
Microwave Microscopy ◽  
Scanning Microwave Microscopy ◽  
Low K

Abstract Scanning Microwave Impedance Microscopy (sMIM) can be used to characterize dielectric thin films and to quantitatively discern film thickness differences. FEM modeling of the sMIM response provides understanding of how to connect the measured sMIM signals to the underlying properties of the dielectric film and its substrate. Modeling shows that sMIM can be used to characterize a range of dielectric film thicknesses spanning both low-k and medium-k dielectric constants. A model system consisting of SiO2 thin films of various thickness on silicon substrates is used to illustrate the technique experimentally.

Structire, Properties, and Process Characteristics of Low-K Materials Prepared by PECVD

1999 ◽  
Vol 565 ◽  
Author(s):  
Y. Shimogaki ◽  
S. W. Lim ◽  
E. G. Loh ◽  
Y. Nakano ◽  
K. Tada ◽  
...  
Keyword(s):  
Growth Rate ◽  
Dielectric Constant ◽  
Gas Flow ◽  
Structural Changes ◽  
Silicon Oxide ◽  
Reactive Species ◽  
Low Dielectric Constant ◽  
Low Dielectric ◽  
Step Coverage ◽  
Low K

AbstractLow dielectric constant F-doped silicon oxide films (SiO:F) can be prepared by adding fluorine source, like as CF4 to the conventional PECVD processes. We could obtain SiO:F films with dielectric constant as low as 2.6 from the reaction mixture of SiH4/N2 O/CF4. The structural changes of the oxides were sensitively detected by Raman spectroscopy. The three-fold ring and network structure of the silicon oxides were selectively decreased by adding fluorine into the film. These structural changes contribute to the decrease ionic polarization of the film, but it was not the major factor for the low dielectric constant. The addition of fluorine was very effective to eliminate the Si-OH in the film and the disappearance of the Si-OH was the key factor to obtain low dielectric constant. A kinetic analysis of the process was also performed to investigate the reaction mechanism. We focused on the effect of gas flow rate, i.e. the residence time of the precursors in the reactor, on growth rate and step coverage of SiO:F films. It revealed that there exists two species to form SiO:F films. One is the reactive species which contributes to increase the growth rate and the other one is the less reactive species which contributes to have uniform step coverage. The same approach was made on the PECVD process to produce low-k C:F films from C2F4, and we found ionic species is the main precursor to form C:F films.

Copper Drifts in Porous Methylsilsesquiazane Low-k Dielectric Films

2000 ◽  
Author(s):  
T. Kikkawa ◽  
S. Mukaigawa ◽  
T. Oda ◽  
T. Aoki ◽  
Y. Shimizu
Keyword(s):  
Dielectric Films ◽  
Low K

Sol–gel deposited xerogel, aerogel and porogen based porous low-k thin films: A comparative investigation

2021 ◽  
pp. 2140019
Author(s):  
Swati Gupta ◽  
Anil Gaikwad ◽  
Ashok Mahajan ◽  
Lin Hongxiao ◽  
He Zhewei
Keyword(s):  
Dielectric Constant ◽  
Sol Gel ◽  
Comparative Investigation ◽  
Crosstalk Noise ◽  
Nanoelectronic Devices ◽  
Low Dielectric ◽  
Interconnect Delay ◽  
Xerogel Films ◽  
Low K ◽  
Porosity Percentage

Low dielectric constant (Low-[Formula: see text]) films are used as inter layer dielectric (ILD) in nanoelectronic devices to reduce interconnect delay, crosstalk noise and power consumption. Tailoring capability of porous low-[Formula: see text] films attracted more attention. Present work investigates comparative study of xerogel, aerogel and porogen based porous low-[Formula: see text] films. Deposition of SiO2 and incorporation of less polar bonds in film matrix is confirmed using Fourier Transform Infra-Red Spectroscopy (FTIR). Refractive indices (RI) of xerogel, aerogel and porogen based low-[Formula: see text] films observed to be as low as 1.25, 1.19 and 1.14, respectively. Higher porosity percentage of 69.46% is observed for porogen-based films while for shrinked xerogel films, it is lowered to 45.47%. Porous structure of low-[Formula: see text] films has been validated by using Field Emission Scanning Electron Microscopy (FE-SEM). The pore diameters of porogen based annealed samples were in the range of 3.53–25.50 nm. The dielectric constant ([Formula: see text]) obtained from RI for xerogel, aerogel and porogen based films are 2.58, 2.20 and 1.88, respectively.

A comparative study on the measurement of toughness of stacks containing low-k dielectric films

2008 ◽  
Vol 85 (11) ◽  
pp. 2322-2328 ◽  
Author(s):  
Z.W. Zheng ◽  
I. Sridhar ◽  
S. Balakumar
Keyword(s):  
Comparative Study ◽  
Dielectric Films ◽  
Low K
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