Preparation and Characterization of High Porosity Si02 Xerogels for Low k Dielectrics

1999 ◽  
Vol 565 ◽  
Author(s):  
M. T. Colomer
Keyword(s):  
Dielectric Constant ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Low Dielectric Constant ◽  
High Porosity ◽  
Silica Xerogels ◽  
Particulate Suspensions ◽  
Low Dielectric ◽  
Intermetal Dielectric ◽  
Low K

AbstractDue to its low dielectric constant, high porosity SiO2 is a potential intermetal dielectric (IMD) film for sub-half micron devices. High porosity SiO2 xerogels with a low dielectric constant were prepared by a sol-gel method. Basic and mixtures of SiO2 sols (acid/base) aqueous particulate suspensions were employed using TEOS as a precursor.Porosity values up to 55% could be obtained for the silica xerogels calcined at 250°C. The porosity values were estimated by means of nitrogen adsorption (BET). The dielectric constant was directly measured using an impedance analyzer and also calculated from the nitrogen adsorption measurements. Both techniques were in good agreement and resulted in a dielectric constant value of 2.32 for xerogels having the highest porosity.

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.

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).

Photo-induced Large Area Growth Of Dielectrics With Excimer Lamps

2000 ◽  
Vol 617 ◽  
Author(s):  
Ian W. Boyd ◽  
Jun-Ying Zhang
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Low Temperature ◽  
Leakage Current ◽  
Sol Gel ◽  
Low Dielectric Constant ◽  
Large Area ◽  
Excimer Lamp ◽  
Low Dielectric ◽  
Current Densities

AbstractIn this paper, UV-induced large area growth of high dielectric constant (Ta2O5, TiO2and PZT) and low dielectric constant (polyimide and porous silica) thin films by photo-CVD and sol-gel processing using excimer lamps, as well as the effect of low temperature LW annealing, are discussed. Ellipsometry, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), UV spectrophotometry, atomic force microscope (AFM), capacitance-voltage (C-V) and current-voltage (I-V) measurements have been employed to characterize oxide films grown and indicate them to be high quality layers. Leakage current densities as low as 9.0×10−8 Acm−2 and 1.95×10−7 Acm−2 at 0.5 MV/cm have been obtained for the as-grown Ta2O5 films formed by photo-induced sol-gel processing and photo-CVD. respectively - several orders of magnitude lower than for any other as-grown films prepared by any other technique. A subsequent low temperature (400°C) UV annealing step improves these to 2.0×10−9 Acm−2 and 6.4× 10−9 Acm−2, respectively. These values are essentially identical to those only previously formed for films annealed at temperatures between 600 and 1000°C. PZT thin films have also been deposited at low temperatures by photo-assisted decomposition of a PZT metal-organic sol-gel polymer using the 172 nm excimer lamp. Very low leakage current densities (10−7 A/cm2) can be achieved, which compared with layers grown by conventional thermal processing. Photo-induced deposition of low dielectric constant organic polymers for interlayer dielectrics has highlighted a significant role of photo effects on the curing of polyamic acid films. I-V measurements showed the leakage current density of the irradiated polymer films was over an order of magnitude smaller than has been obtained in the films prepared by thermal processing. Compared with conventional furnace processing, the photo-induced curing of the polyimide provided both reduced processing time and temperature, A new technique of low temperature photo-induced sol-gel process for the growth of low dielectric constant porous silicon dioxide thin films from TEOS sol-gel solutions with a 172 nm excimer lamp has also been successfully demonstrated. The dielectric constant values as low as 1.7 can be achieved at room temperature. The applications investigated so far clearly demonstrate that low cost high power excimer lamp systems can provide an interesting alternative to conventional UV lamps and excimer lasers for industrial large-scale low temperature materials processing.

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.

Stress Development in Low Dielectric Constant Silica Films During Drying and Heating Process

1999 ◽  
Vol 594 ◽  
Author(s):  
Mengcheng Lu ◽  
C. Jeffrey Brinker
Keyword(s):  
Dielectric Constant ◽  
Tensile Stress ◽  
Sol Gel ◽  
Low Dielectric Constant ◽  
Heating Process ◽  
Residual Tensile Stress ◽  
Silica Films ◽  
Stress Development ◽  
Low Dielectric

AbstractLow dielectric constant silica films are made using a surfactant templated sol-gel process (K∼2.5) or an ambient temperature and pressure aerogel process (K∼1.5). This paper will present the in-situ measurement and analysis of stress development during the making of these films, from the onset of drying till the end of heating. The drying stress is measured by a cantilever beam technique; the thermal stress is measured by monitoring the wafer curvature using a laser deflection method. During the course of drying, the surfactant templated films experience a low drying stress due to the influence of the surfactant on surface tension and extent of siloxane condensation. The aerogel films first develop a biaxial tensile stress due to solidification and initial drying. At the final stage of drying where the drying stress vanishes, dilation of the film recreates the porosity of the wet gel state, reducing the residual stress to zero. For the surfactant templated films, very small residual tensile stress remains after the heat treatment is finished (∼30MPa). Aerogel film has almost no measurable stress developed in the calcination process. In situ spectroscopic ellipsometry analysis during drying and heating, and TGA/DTA are all used to help understand the stress development.

Dielectric Properties of Sol - Gel Silica Glasses

1986 ◽  
Vol 72 ◽  
Author(s):  
G. V. Chandrashekhar ◽  
M. W. Shafer
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Elemental Carbon ◽  
Sol Gel ◽  
Fused Silica ◽  
Dielectric Constants ◽  
Low Dielectric Constant ◽  
Silica Glasses ◽  
Low Dielectric ◽  
Gel Technique

AbstractDielectric properties have been measured for a series of porous and fully densified silica glasses, prepared by the sol-gel technique starting from Si-methoxide or Si-fume. The results for the partially densified glasses do not show any preferred orientation for porosity. When fully densified (˜2.25 gms/cc) without any prior treatment of the gels, they have dielectric constants of ≥ 6.5 and loss factors of 0.002 at 1 MHz, compared to values of 3.8 and <0.001 for commercial fused silica. There is no corresponding anomaly in the d.c. resistivity. Elemental carbon present to the extent of 400–500 ppm is likely to be the main cause for this enhanced dielectric constant. Extensive cleaning of the gels prior to densification to remove this carbon were not completely successful pointing to the difficulty in preparing high purity, low dielectric constant glasses via the organic sol-gel route at least in the bulk form.

Study on the Dielectric Properties of Hybrid and Porous Polyimide-Silica Films

2008 ◽  
Vol 47-50 ◽  
pp. 973-976 ◽  
Author(s):  
Yi He Zhang ◽  
Qing Song Su ◽  
Li Yu ◽  
Hong Zheng ◽  
Hai Tao Huang ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Sol Gel ◽  
Silica Particles ◽  
Low Dielectric Constant ◽  
Hybrid Films ◽  
Porous Films ◽  
Silica Films ◽  
Low Dielectric ◽  
Dimethyl Acetamide ◽  
Sol Gel Process

A sol-gel process was used to prepare polyimide-silica hybrid films from the polyimide precursors and TEOS in N,N- dimethyl acetamide, then the hybrid film was treated with hydrofluoric acid to remove the dispersed silica particles, leaving pores with diameters between 80nm to 1µm, depending on the size of silica particles. The structure and dielectric constant of the hybrid and porous films were characterized by FTIR,SEM. The porous films displayed relatively low dielectric constant compared to the hybrid polyimide-silica films.

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.

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.

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