Experimental and numerical analyses on recovery of polymer deformation after demolding in the hot embossing process

Takagi, Hideki; Takahashi, Masaharu; Maeda, Ryutaro; Ônishi, Yoshihiro; Iriye, Yasuroh; Iwasaki, Takuya; Hirai, Yoshihiko

doi:10.1116/1.2987956

Cited by 14 publications

(10 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Experimentally, the leveling of thin polymer films near the glass transition temperature ( T g ) has been used to investigate the surface mobility of polymer chains. − However, apart from dewetting and instability phenomena, little work on the topographical impact of the viscoelastic relaxation of patterns above T g has been published. In fact, studies in that field come from the nanoimprint community for whom elastic recovery is a major technological issue. − Ding et al , and Jones et al studied the decay of imprinted polymer patterns during annealing. Although they were able to capture with great accuracy the temporal evolution of the pattern, they focused only on periodical and simple line–space patterns.…”

Section: Introductionmentioning

confidence: 99%

Viscoelastic Leveling of Annealed Thin Polystyrene Films

2014

View full text Add to dashboard Cite

Theoretical and experimental work on nanoscale viscoelastic flows of polystyrene melts is presented. The reflow above the glass transition temperature (T(g)) of a continuous patterned film is characterized. Attention is paid to the topographical consequences of the flow rather than to the temporal description of the leveling of the film. In the framework of capillary wave theory, it is shown that only the shortest spatial wavelengths of the topography exhibit an elastic behavior, while long waves follow a viscous decay. The threshold wavelength depends on the surface tension, on the elastic plateau modulus, and, for ultrathin films, on the film thickness. Besides, for polystyrene, this threshold is a nanoscale parameter and weakly depends on the temperature of annealing. Experiments are conducted on polystyrene 130 kg/mol submicrometer films. The samples are embossed using thermal nanoimprint technology and then annealed at different temperatures between T(g) + 10 °C and T(g) + 50 °C. The smoothed topographies of the films are measured by atomic force microscopy and compared to a single-mode Maxwell leveling model and a more elaborated model based on reptation theory.

show abstract

Section: Introductionmentioning

confidence: 99%

Viscoelastic Leveling of Annealed Thin Polystyrene Films

2014

View full text Add to dashboard Cite

show abstract

“…Much work has been done on the study on the recovery of polymer during hot embossing. [2][3][4][5][6][7] Some researches drew conclusions based on experiments without discussing the simulation method of recovery. [2][3][4] While Sheer et al got the stress distribution in polymer, 5) but they did not calculate to predict the recovery contour.…”

Section: Introductionmentioning

confidence: 99%

Simulation and Experimental Study on Recovery of Polymer during Hot Embossing

Jin¹,

Gao²,

Liu³

et al. 2009

jjap

View full text Add to dashboard Cite

The recovery of polymer caused by the stress in polymer has a significant effect on the imprinting accuracy in three-dimensional (3D) hot embossing lithography (HEL). A method is proposed in this paper to simulate the recovery defect of a 3D structure. The filling characteristics of polymer and the stress distribution in polymer are analyzed using a combination model of non-Newtonian fluid and linearelastic solid. The recovery of polymer after demolding is predicted by simulating the process of stress release. The good agreement between simulation and experimental results with an error of structure depth under 4% indicates that the proposed method is effective in optimizing the process parameters, and it can therefore be used to reduce the recovery of polymer thereby improving the 3D imprinting accuracy.

show abstract

“…In the best of cases, demolding is entirely a 2D process, which means that the stamp is lifted and detached from the structures in vertical direction [90][91][92][93][94][95][96][97][98][99][100][101][102][103][104][105]. For ideal structures with vertical sidewalls and no shrinkage, one would only have to distinguish between a state of adhesion on all surfaces, separation from horizontal planes, a state of sliding along vertical sidewalls and a state of complete separation, after a sudden detachment.…”

Section: Demoldingmentioning

confidence: 99%

Nanoimprint lithography: 2D or not 2D? A review

Schift

2015

Appl. Phys. A

107

View full text Add to dashboard Cite

Nanoimprint lithography (NIL) is more than a planar high-end technology for the patterning of wafer-like substrates. It is essentially a 3D process, because it replicates various stamp topographies by 3D displacement of material and takes advantage of the bending of stamps while the mold cavities are filled. But at the same time, it keeps all assets of a 2D technique being able to pattern thin masking layers like in photon-and electron-based traditional lithography. This review reports about 20 years of development of replication techniques at Paul Scherrer Institut, with a focus on 3D aspects of molding, which enable NIL to stay 2D, but at the same time enable 3D applications which are ''more than Moore.'' As an example, the manufacturing of a demonstrator for backlighting applications based on thermally activated selective topography equilibration will be presented. This technique allows generating almost arbitrary sloped, convex and concave profiles in the same polymer film with dimensions in micro-and nanometer scale.

show abstract

Experimental and numerical analyses on recovery of polymer deformation after demolding in the hot embossing process

Abstract: Simulations of nonuniform embossing: The effect of asymmetric neighbor cavities on polymer flow during nanoimprint lithography

Cited by 14 publications

References 7 publications

Viscoelastic Leveling of Annealed Thin Polystyrene Films

Viscoelastic Leveling of Annealed Thin Polystyrene Films

Simulation and Experimental Study on Recovery of Polymer during Hot Embossing

Nanoimprint lithography: 2D or not 2D? A review

Contact Info

Product

Resources

About