Glass transition temperature and thermal expansion behaviour of polymer films investigated by variable temperature spectroscopic ellipsometry

Kahle, O.; Wielsch, Uwe; Metzner, H.; Bauer, Jörg; Uhlig, C.; Zawatzki, C.

doi:10.1016/s0040-6090(97)00999-1

Cited by 65 publications

(62 citation statements)

References 9 publications

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“…The particular way in which the refractive index is a function of the light wavelength is referred to as "dispersion formulae". "Cauchy" formulae is the simplest dispersion used, and it is particularly suitable to describe the optical properties of weakly absorbing materials [36] such as various transparent polymers [37][38][39]. Therefore, our complete model used to fit the ellipsometric data consisted of a 3-layer structure having a Cauchy layer at the surface representing the active layer, an intermediate 2-nm silicon dioxide layer [40], and 1 mm silicon substrate.…”

Section: Ellipsometry Analysesmentioning

confidence: 99%

Investigating the void structure of the polyamide active layers of thin-film composite membranes

Lin

López

Ramon

et al. 2016

Journal of Membrane Science

189

151

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Section: Ellipsometry Analysesmentioning

confidence: 99%

Investigating the void structure of the polyamide active layers of thin-film composite membranes

Lin

López

Ramon

et al. 2016

Journal of Membrane Science

189

151

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“…The dimension dependence of the glass transition temperature ͑T g ͒ of free standing and supported ultra thin polymer films have been described extensively in the literature, [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] and there are some reports of dimension dependent transport 16 -20 and mechanical properties [21][22][23][24] in nanoscale polymeric systems as well. In most commercial applications of films and coatings, the thickness of the polymer does not approach the sub-100 nm scale and the phenomena referred to above do not affect the properties, processing, and usefulness of the materials.…”

Section: Introductionmentioning

confidence: 99%

Extraordinary elevation of the glass transition temperature of thin polymer films grafted to silicon oxide substrates

Tate¹,

Fryer

Pasqualini

et al. 2001

The Journal of Chemical Physics

140

127

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We used local thermal analysis and ellipsometry to measure the glass transition temperatures (T g ) of supported thin films of poly͑4-hydroxystyrene͒ ͑PHS͒ and hydroxy terminated polystyrene ͑PS-OH͒. The films were spuncast from solution onto silicon oxide substrates and annealed under vacuum at elevated temperatures to graft the polymer to the substrate. Grafting was verified and characterized in terms of the thickness of and the advancing contact angle of water on the residual layer after solvent extraction. For PHS, each segment of the polymer chain was capable of grafting to the substrate. The thickness of the residual layer increased with increasing annealing temperature. For this polymer the critical thickness below which the T g of the film deviated from the bulk value was nearly 200 nm after annealing at the highest temperature ͑190°C͒; the T g of films 100 nm thick or less were elevated by more than 50°C above the bulk value. For PS-OH films the polymer was only capable of grafting at one chain end, forming a brush layer at the substrate interface. The critical thicknesses for PS-OH films and the T g elevations were substantially higher than for ungrafted PS films, but were not as large as for PHS. The film thickness dependence of T g for PHS and PS-OH were well described as piecewise linear, consistent with a ''dual-mechanism'' model.

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“…For example, it is documented that a polymer glass transition temperature (T g ) can decrease, [1][2][3][4][5][6][7][8][9] increase, [8][9][10][11][12][13] or remain constant 14,15 when the film thickness approaches a few multiples of the radius of gyration (R g ), with shifts as great as Ϯ50°C reported. These length scales approach the unperturbed dimensions of the macromolecule and confinement induced property deviations need to be considered.…”

Section: Introductionmentioning

confidence: 99%

Thin film confinement effects on the thermal properties of model photoresist polymers

Soles¹,

Lin²,

Lenhart³

et al. 2001

Journal of Vacuum Science &Amp; Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

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The demand to print increasingly smaller microelectronic device features means that the thickness of the polymer films used in the lithographic processes must decrease. The thickness of these films is rapidly approaching the unperturbed dimensions of the polymer, length scales at which confinement deviations and dewetting are a significant concern. We combine specular x-ray reflectivity ͑SXR͒ and incoherent neutron scattering ͑INS͒ to probe the thermal stability and dynamical effects of thin film confinement in poly͑hydroxy styrene͒ ͑PHS͒, a polymer used in a majority of the 248 nm deep UV photoresists. PHS forms stable thin films ͑down to 5 nm͒ that do not dewet over a wide temperature range on Si surfaces ranging from hydrophilic to hydrophobic. The surface energy has a profound influence on the magnitude of the thin film expansion coefficient, especially above the glass transition, in films as thick as 100 nm. Confinement also appears to suppress the mean-square atomic displacements and the level of anharmonicity in the dynamics, primarily above the bulk glass transition.

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Glass transition temperature and thermal expansion behaviour of polymer films investigated by variable temperature spectroscopic ellipsometry

Cited by 65 publications

References 9 publications

Investigating the void structure of the polyamide active layers of thin-film composite membranes

Investigating the void structure of the polyamide active layers of thin-film composite membranes

Extraordinary elevation of the glass transition temperature of thin polymer films grafted to silicon oxide substrates

Thin film confinement effects on the thermal properties of model photoresist polymers

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