Removal of moisture contamination from porous polymeric low‐k dielectric films

Self Cite

A novel approach is developed and demonstrated to characterize the sampling line effects during dynamic monitoring of fluid concentrations. The "sampling line" in this study refers to all components between the point of fluid sampling and the point of analyzer sensor. In general, sampling lines introduce errors in measurements by altering the sample properties due to the fluid transport in the line as well as the adsorption and desorption of fluid constituents on the surfaces of the sampling components that come into contact with the sample fluid. A methodology based on a sampling line simulator is developed for taking these effects into account and correcting the measurements. The model is validated by direct experimental measurements using several different analyzers under various conditions. The sampling line simulator can be used to analyze the effect of various sampling configurations and operating conditions; this would be helpful in the design of sampling lines and their location. An algorithm is proposed that can be used to convert concentration values measured and reported by the analyzer to the concentration values at the point of sampling that are the actual and desired values.

Section: Resultsmentioning

confidence: 99%

Section: Experimental Approachmentioning

confidence: 99%

Effect of Sampling Line Characteristics on the Dynamic Monitoring of Fluid Concentrations

Juneja

Yao

Shadman

2009

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“…The observed fluctuations in the mass spectrometer readout are due to slight variations in the ambient temperature and gas flow rates. 28 These fluctuations are secondary and have no significant effect on the final results.…”

Section: Resultsmentioning

confidence: 99%

Mechanism and Kinetics of Nonequilibrium and Multilayer Adsorption and Desorption of Gases on Solids

Juneja

Iqbal

Yao

et al. 2006

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A novel approach to the characterization of dynamic interactions of gases with solid surfaces is developed. A model is developed to represent the simultaneous adsorption and desorption processes in these systems. The model can simulate properties of nonequilibrium adsorption and desorption processes as well as the equilibrium state (isotherms and isobars). It also provides information on the distribution of loading of tightly bound molecules as the first layer on the surface as well as loosely bound physisorbed molecules as the upper layers during a transient process and at the equilibrium state. The model is validated and applied to the adsorption of moisture on oxides (ZrO2 and HfO2). Practical application of this work is shown by optimizing the purge recipes for removal of moisture from ZrO2 film. Optimization helps in lowering gas and energy consumption as well as reducing the purge times.

“…For significant polymerization to have occurred in the bulk fluid phase, there would have to have been a substantial amount of water or other hydroxyl-bearing molecules dissolved in the scCO 2 . Water was supplied by (i) preadsorption on the matrix, (ii) chemical displacement of −OH groups by scCO 2 (which formed water after picking up a hydrogen), , or (iii) loaded because no purge was used to exclude ambient water vapor, resulting in an initial water concentration in the scCO 2 of 0.1 mM, as estimated for the hardware configuration used for this work.…”

Section: Discussionmentioning

confidence: 99%

Surface Modification of Porous Silicon-Based Films Using Dichlorosilanes Dissolved in Supercritical Carbon Dioxide

Vyhmeister

Valdés-González

Muscat

et al. 2013

Dimethyldichlorosilane (DMDCS), diethyldichlorosilane (DEDCS), and dibutyldichlorosilane (DBDCS) were dissolved in supercritical CO 2 at two concentration levels to modify hydrolyzed porous surfaces via silylation reactions. Plasmadamaged methylsilsesquioxane samples were loaded in a batch reactor with the chlorosilanes; when introduced, the low-viscosity supercritical CO 2 dissolved and transported the chlorosilanes to the porous surface. Samples were characterized using Fourier transform infrared spectroscopy (FTIR), ellipsometry, goniometry, and electrical measurements, and compared against untreated samples. Reactions between the chlorosilanes and substrate hydroxyls were strongly dependent on the length of the alkyl group on the chlorosilane, but independent of concentration. FTIR analyses showed a decreased intensity for infrared (IR)-isolated/ geminal OH vibrations (100%, 93.9% ± 5.4%, and 95.4% ± 4.3% for DMDCS, DEDCS, and DBDCS, respectively), but DEDCS and DBDCS resulted in 3.9% ± 5.0% and 20.9% ± 8.7% increases in hydrogen bonding, respectively. DMDCS was more successful, showing a 14.4% ± 9.8% reduction in hydrogen bonding. Goniometry measured hydrophobic contact angles that were consistently greater than 81°, irrespective of the chemistry used. Ellipsometry showed a strong dependence between the thickness of the deposited layers and the chlorosilane alkyl group (19.0 nm ± 1.6 nm, 31.3 nm ± 4.8 nm, and 74.2 nm ± 4.7 nm for DMDCS, DEDCS, and DBDCS, respectively). Electrical measurements indicated improved hydroxyl group elimination with shorter alkyl groups (dielectric constant decreased from 3.5 for plasma-ashed methylsilsesquioxane samples to 2.59, 2.97, and 3.4 for DMDCS, DEDCS, and DBDCS, respectively). DMDCS was found to participate in intramolecular and intermolecular reactions while the surface-modifying agents with longer hydrocarbon chains underwent predominantly intermolecular reactions, resulting in the thicker deposited layers.