CO2 promotes penetration and removal of aqueous hydrocarbon surfactant cleaning solutions and silylation in low-k dielectrics with 3nm pores

Keagy, John A.; Li, Yuan; Green, Peter; Johnston, Keith P.; Weber, Frank; Rhoad, J.T.; Busch, Eric; Wolf, Peter

doi:10.1016/j.supflu.2007.02.007

Cited by 19 publications

(12 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This simulation result shows that the presence of CO 2 fluids decreases the wettability of the surface. This obtained phenomenon is qualitatively consistent with the experimental observations on the wetting behavior at the CO 2 /water/glass [9] and CO 2 /water/polystyrene [10] interfaces. Figure 4 illustrates the water wetting behavior on the hydrophobic surface.…”

Section: Models and Methodssupporting

confidence: 91%

“…The successful removal *Corresponding author (email: yangxia@njut.edu.cn) of residues has been achieved in just 2 min for porous material with a 130 nm pattern feature. Keagy et al [9] demonstrated experimentally that the scCO 2 fluid can rapidly remove aqueous surfactant solutions from a methylsilsesquioxane (MSQ) low dielectric constant film with 3 nm pores. The addition of CO 2 fluid is expected to reduce the interfacial tension and thus lower the capillary pressure of nanopores.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Molecular dynamics simulation of wetting behavior at CO2/water/solid interfaces

2010

View full text Add to dashboard Cite

We used molecular dynamics simulation to demonstrate the microscopic wetting behavior of two solid model surfaces for the first time. Hydrophilic and hydrophobic features were modeled in a dense CO 2 fluid environment under various densities. The water droplet loses contact with the surface under the influence of higher density CO 2 fluids on the hydrophobic surface. For the hydrophilic surface, no separation between the water droplet and the surface was observed. However, the contact angle of the water droplet on the hydrophilic surface was found to increase with the fluid density. The effect of dense CO 2 fluid on the surface wettability can be interpreted in terms of enhanced interactions from the surrounding CO 2 molecules. wettability, solid surface, molecular simulation, hydrophilic, hydrophobic, supercritical CO 2 Citation:Liu S Y, Yang X N, Qin Y. Molecular dynamics simulation of wetting behavior at CO 2 /water/solid interfaces.

show abstract

Section: Models and Methodssupporting

confidence: 91%

mentioning

confidence: 99%

Molecular dynamics simulation of wetting behavior at CO2/water/solid interfaces

2010

View full text Add to dashboard Cite

show abstract

“…Recently, several studies of block copolymer thin films used CO 2 to induce the ordering of copolymer templates,5–8 to control the spatial distribution of metal nanoparticles in copolymer matrices,9 and to diffuse precursors in copolymers for the synthesis of nanoporous materials 10. In addition to polymer processing, supercritical CO 2 has been investigated as a potential medium in many microelectronic thin film processes 11–18. For example, it has been shown that CO 2 promotes penetration and removal of aqueous surfactant cleaning solutions in methylsilsesquioxane (MSQ) low dielectric constant ( k ) films 15.…”

Section: Introductionmentioning

confidence: 99%

Role of interfacial interactions on the anomalous swelling of polymer thin films in supercritical carbon dioxide

Park

Lim

et al. 2007

J Polym Sci B Polym Phys

Self Cite

View full text Add to dashboard Cite

It has recently been shown that thin polymer films in the nanometer thickness range exhibit anomalous swelling maxima in supercritical CO 2 (Sc-Co 2 ) in the vicinity of the critical point of CO 2 . The adsorption isotherm of CO 2 on carbon black, silica surfaces, porous zeolites, and other surfaces, is known to exhibit anomalous maxima under similar CO 2 conditions. It is believed that because CO 2 possesses a low cohesive energy density, there would be an excess amount of CO 2 at the surfaces of these materials and hence the CO 2 /polymer interface. This might cause excess CO 2 in the polymer films near the free surface, and hence the swelling anomaly. In addition, an excess of CO 2 would reside at the polymer/substrate and polymer/CO 2 interfaces for entropic reasons. These interfacial effects, as have been suggested, should account for an overall excess of CO 2 in a thin polymer film compared to the bulk, and would be responsible for the anomalous swelling. In this study, we use in situ spectroscopic ellipsometry to investigate the role of interfaces on the anomalous swelling of polymer thin films of varying initial thicknesses, h 0 , exposed to Sc-CO 2 . We examined three homopolymers, poly(1,1 0 -dihydroperflurooctyl methacrylate) (PFOMA), polystyrene (PS), poly(ethylene oxide) (PEO), that exhibit very different interactions with Sc-CO 2 , and the diblock copolymer of PS-b-PFOMA. We show that the anomalous swelling cannot be solely explained by the excess adsorption of CO 2 at interfaces. V V C 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45:

show abstract

“…As the features shrink to nano-scale, the cleaning solution contained in the acid and alkali and strong oxidizing agents can cause surface microroughness and structural deformation, aqueous cleaning is unfeasible due to surface tension and capillary forces increase [2][3][4]. Nanoporous silica (NPS) is a hotspot in ultra-low dielectric constant material domain, but highly corrosive chemical cleaning will destroy the material, the capillary force of water can also cause structural collapse [5]; The traditional cleaning has consumed a great deal of pure water and organic solvent, which inevitably caused serious environmental pollution, physical hazards and water waste. Therefore, looking for environmental friendly solvent is a trend for microelectronics and other high-tech technology.…”

Section: Introductionmentioning

confidence: 99%