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.

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).

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.

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.

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.

Robust spin-on-glass poly(methyl)silsesquioxane-based low-k materials derived from a cyclic siloxane precursor

RSC Advances ◽  
2015 ◽  
Vol 5 (82) ◽  
pp. 66511-66517 ◽  
Author(s):  
Albert S. Lee ◽  
Sung Yeoun Oh ◽  
Seung-Sock Choi ◽  
He Seung Lee ◽  
Seung Sang Hwang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Dielectric Constant ◽  
Low Dielectric Constant ◽  
Cyclic Siloxane ◽  
Low Dielectric ◽  
Methyl Silsesquioxane ◽  
Low K

Low dielectric constant poly(methyl)silsesquioxane spin-on-glass resins incorporating a cyclic precursor exhibited exceptional mechanical properties to withstand CMP processes.

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.

Chemical-Mechanical Planarization of Low-k Polymers for Advanced IC Structures

2002 ◽  
Vol 124 (4) ◽  
pp. 362-366 ◽  
Author(s):  
Christopher L. Borst ◽  
Dipto G. Thakurta ◽  
William N. Gill ◽  
Ronald J. Gutmann
Keyword(s):  
Dielectric Constant ◽  
Surface Chemistry ◽  
Chemical Mechanical Planarization ◽  
Low Dielectric Constant ◽  
Chemical Company ◽  
Low Dielectric ◽  
Scale Models ◽  
Physically Based ◽  
Thickness Measurements ◽  
Low K

Successful integration of copper and low dielectric constant (low-k) materials is dependent on robust chemical-mechanical planarization (CMP) during damascene patterning. This process includes the direct removal of copper and interaction of the copper slurry with the underlying dielectric. Experiments were designed and performed to examine the CMP of two low-k polymers from Dow Chemical Company, bis-benzocyclobutene (BCB*, k=2.65) and “silicon-application low-k material” (SiLK* resin, k=2.65) with both acidic slurries suitable for copper damascene patterning and a KH phthalate-based model slurry developed for SiLK. Blanket polymer films were polished in order to determine the interactions that occur when copper and liner materials are removed by the damascene CMP process. Removal rates were obtained from material thickness measurements, post-CMP surface topography from AFM scans, and post-CMP surface chemistry from XPS measurements. Physically based wafer-scale models are presented which are compatible with the experimental results.

Ultra Low-dielectric-constant Materials for 65nm Technology Node and Beyond

2004 ◽  
Vol 812 ◽  
Author(s):  
Hao Cui ◽  
Darren Moore ◽  
Richard Carter ◽  
Masaichi Eda ◽  
Peter Burke ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Films ◽  
Low Dielectric Constant ◽  
Plasma Damage ◽  
Pore Characteristics ◽  
Hydrogenated Silicon ◽  
Bonding Structure ◽  
Low Dielectric ◽  
Etch Stop ◽  
Low Dielectric Constant Materials

AbstractPore characteristics including pore size distribution, porosity, and pore interconnectivity of PECVD SiCOH inter- layer dielectric (ILD) materials with different dielectric constant (κ) values have been studied. Oxygen plasma damage to SiCOH low-κ films increases dramatically as the κ value decreases. Simulations showed that, compared to the ILD film, the overhead dielectric films have a significant impact on the overall effective κ (κeff) of the BEOL interconnects. Reducing the κ values of these overhead films helps to alleviate the pressure on the κ value requirement of the ILD materials while still meeting the κeff target. Ultra low-κ (ULK) PECVD hydrogenated silicon carbide (H:SiC) films with a κ of 3.0 have been studied for the etch-stop applications. Studies of the chemical composition and bonding structure suggest that less Si-C networκs are formed and more micro-porosity are incorporated in the ULK H:SiC film. The leakage current of the ULK H:SiC film is found to be about 5 times lower than the H:S iC and H:SiCN films with higher κ values. The etch rate of ULK H:SiC film using a standard SiCOH ILD etch chemistry has been found to be negligible. Such an extremely high etch selectivity maκes these films very good etch-stop layers.

Low-K Porous Spin-On-Glass

1999 ◽  
Vol 565 ◽  
Author(s):  
Paul A. Kohl ◽  
Agnes Padovani ◽  
Michael Wedlake ◽  
Dhananjay Bhusari ◽  
Sue Ann ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Elevated Temperatures ◽  
Porous Silica ◽  
Dielectric Materials ◽  
Decomposition Products ◽  
Air Gaps ◽  
Low Dielectric ◽  
Polymer Decomposition ◽  
Low K ◽  
By Products

AbstractPreviously, the fabrication of air-gap structures for electrical interconnections was demonstrated using a sacrificial polymer encapsulated in conventional dielectric materials. The air-gaps were formed by thermally decomposing the sacrificial polymer and allowing the by-products to diffuse through the encapsulating dielectric. The diffusivity of the polymer decomposition products is adequate at elevated temperatures to allow the formation of air-gaps. This process was extended to form low dielectric constant, porous silica from commercially available methylsilsesquioxane (MSQ) by the addition of the sacrificial polymer to the MSQ. The porous MSQ film was thermally cured followed by decomposition of the NB at temperatures above 400°C. The dielectric constant of the MSQ was lowered from 2.7 to 2.3 by creating 70 nm pores in the MSQ. The voids created in the MSQ appeared to exhibit a closed-pore structure.

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