Positron Depth-Profiling of Polymer Interfaces

Gidley, D. W.; Demaggio, G. B.; Frieze, W. E.; Zhu, Ming; Hristov, Hristo; Yee, Albert F.

doi:10.4028/www.scientific.net/msf.255-257.635

Cited by 10 publications

(9 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…If the state of thin film confinement enhances packing, hindered diffusion would be the natural consequence. This picture is reasonable given the experimental evidence for a dynamically dead layer (retarded mobility) at the interface of a polymer and a rigid substrate [29][30][31][32][33]. Then, when water diffuses into these thin films, mobility is enhanced due to the plasticization effect.…”

Section: Discussionmentioning

confidence: 71%

Polymer dynamics and diffusive properties in ultrathin photoresist films

Soles

Jones

Lenhart

et al. 2003

Advances in Resist Technology and Processing XX

View full text Add to dashboard Cite

A series of experiments are presented to demonstrate thin film confinement effects on the diffusive properties in poly(tert-butoxycarboxystyrene) (PBOCSt). Bilayer diffusion couple measurements reveal that as the thickness of a PBOCSt film is decreased, the kinetics of the deprotection reaction-front propagation (a process involving both the diffusion and reaction of photochemically activated acidic protons) are dramatically hindered. Incoherent neutron scattering measurements suggest that this retardation can be traced to a suppression of local fast relaxations (200 MHz or faster) native to the PBOCSt polymer. The reduced mobility in the thin PBOCSt films is further confirmed with moisture vapor uptake studies performed on a quartz crystal microbalance (QCM). As the film thickness drops below 500 Å there is a strong reduction in the diffusivity of water in the film. In total, these are the first evidences suggesting that the deviations in lithographic performance with decreasing film thickness observed with the bilayer experiments are due to changes in mobility, not reactivity, within a chemically amplified resist.

show abstract

Section: Discussionmentioning

confidence: 71%

Polymer dynamics and diffusive properties in ultrathin photoresist films

Soles

Jones

Lenhart

et al. 2003

Advances in Resist Technology and Processing XX

View full text Add to dashboard Cite

show abstract

“…6 A well-documented property of thin polymer films that exhibits dimensional dependence is the glass transition temperature (T g ). [7][8][9][10][11][12][13][14][15][16] Recently, there has been great interest in quantifying the effect of the substrate on the T g of ultrathin polymer films. Keddie and Jones performed the first study of the relative influence of two different substrates, gold and silicon oxide, on the T g of ultrathin films of poly(methyl methacrylate) (PMMA).…”

Section: Introductionmentioning

confidence: 99%

“…Recent work has shown that the structure, wetting, and mobility of polymers in the form of ultrathin films differ greatly from the bulk. − For supported films, properties also depend on the substrate . A well-documented property of thin polymer films that exhibits dimensional dependence is the glass transition temperature ( T g ). − Recently, there has been great interest in quantifying the effect of the substrate on the T g of ultrathin polymer films. Keddie and Jones performed the first study of the relative influence of two different substrates, gold and silicon oxide, on the T g of ultrathin films of poly(methyl methacrylate) (PMMA) .…”

Section: Introductionmentioning

confidence: 99%

Dependence of the Glass Transition Temperature of Polymer Films on Interfacial Energy and Thickness

Fryer¹,

Peters²,

Kim³

et al. 2001

Macromolecules

486

493

View full text Add to dashboard Cite

The glass transition temperatures (Tg's) of ultrathin films (thickness 80-18 nm) of polystyrene (PS) and poly(methyl methacrylate) (PMMA) were measured on surfaces with interfacial energies (γSL) ranging from 0.50 to 6.48 mJ/m 2 . The surfaces consisted of self-assembled films of octadecyltrichlorosilane (OTS) that were exposed to X-rays in the presence of air. Exposure to X-ray radiation systematically modified the OTS by incorporating oxygen-containing groups on the surface. The interfacial energy for PS and PMMA on the OTS surface was quantified as a function of X-ray dose using the Fowkes-van Oss-Chaudhury-Good model of surface tension. The T g values of the films were characterized by three complementary techniques: local thermal analysis, ellipsometry, and X-ray reflectivity. Within the resolution of the techniques, the results were in agreement. At low values of γSL, the Tg values of PS and PMMA films were below the respective bulk values of the polymers. At high values of γSL, the Tg values of PS and PMMA films were higher than the bulk values and increased monotonically with increasing γSL. The deviation of the Tg values of the films compared to the bulk values increased with decreasing film thickness. For a specific film thickness of PS and PMMA, the difference between the Tg of the film and Tg of the bulk polymer (∆Tg ) Tg film -Tg bulk ) scaled linearly with γSL irrespective of the chemistry of the polymer.

show abstract

“…(iii) Using conventional positron annihilation techniques, such like PALS or the doppler-broadening of annihilation radiation (DBAR), polymer blends having a three-dimensional morphology may be studied. (iv) By means of a slow positron beam combined with the DBAR technique 20,21 and the PALS technique, it is possible to investigate model systems of thin planar layers.…”

Section: Introductionmentioning

confidence: 99%

Positron Annihilation Lifetime Spectroscopy (PALS) for Interdiffusion Studies in Disperse Blends of Compatible Polymers: A Quantitative Analysis

et al. 2002

View full text Add to dashboard Cite

Positron annihilation lifetime spectroscopy (PALS) and differential scanning calorimetry (DSC) were used to study the interdiffusion in a particle-matrix system consisting of the miscible polymers poly(vinyl chloride) (particles) and poly(n-butyl methacrylate) (matrix, 30:70 and 50:50 w/w). Starting from the demixed state of the blends, the transition to the mixed state during annealing at 110 °C was investigated. We deliver further evidence that PALS parameters such as the orthopositronium intensity I 3 and the average positron lifetime τav respond to chemical inhomogeneities in blends and their disappearance due to mutual diffusion of molecules of both phases. The response is due to inhibition of Ps formation by one of the constituents when its molecules migrate into the phase made from the second one. A core-shell model for the description of the o-Ps response to a local chemical inhomogeneity is developed which makes use of a calculated concentration-distance profile. The comparison with the experiment allows the estimation of the interface width and of kinetic parameters, such as the exponent of the time dependence of the interface width and the coefficient of mutual diffusion. The potential and the limitation of this new technique are discussed.

show abstract

Positron Depth-Profiling of Polymer Interfaces

Cited by 10 publications

References 0 publications

Polymer dynamics and diffusive properties in ultrathin photoresist films

Polymer dynamics and diffusive properties in ultrathin photoresist films

Dependence of the Glass Transition Temperature of Polymer Films on Interfacial Energy and Thickness

Positron Annihilation Lifetime Spectroscopy (PALS) for Interdiffusion Studies in Disperse Blends of Compatible Polymers: A Quantitative Analysis

Contact Info

Product

Resources

About