Local mass transport and its effect on global pattern replication during hot embossing

Schulz, H.; Wissen, M.; Scheer, Hella-Christin

doi:10.1016/s0167-9317(03)00128-x

Cited by 57 publications

(52 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When cavity sizes vary greatly over a global embossing tool, due to the quadratic dependence of fill time on indenter width, the limiting effective S MAX can alone dominate the fill time. The filled small-sized flow field characterizing non-uniform embossing agrees well with reports that long-range residual layer uniformity resulting from polymer flow between sections of different pattern density is independent of pattern size [13].…”

Section: Resultssupporting

confidence: 88%

“…The increase in inner indenter width has little effect on the filling time of the inner cavity, since ample polymer is locally available to fill the cavity and single peak flow is limited by the flow of polymer into the cavity, not the flow of the indenter into polymer [10]. As the ratio of polymer available to polymer required for local cavity filling increases, long range flow effects develop causing polymer transport between global tool sections, as noted in [13]. Figure 3c shows total time to fill increasing with increasing inner indenter width and total indenter width, i.e.…”

Section: Resultsmentioning

confidence: 99%

“…A few groups have studied large-scale flow field effects with non-uniform embossing tools [11][12][13][14], noting limitations in simultaneous replication of patterns having large and small features in close proximity. Correlation and crosstalk of stress and flow fields of simple geometries arises when a single embossing tool contains multiple, non-uniform feature geometries.…”

Section: Introductionmentioning

confidence: 99%

“…Viscous polymer flow over large areas limits full replication and uniformity of residual layer thickness as incomplete filling and tool warping result due to non-uniform deformation. Simultaneous replication of combined features having significantly different sizes requires long imprint times compared to uniform fields [11][12][13]15].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

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

Rowland

King

Sun

et al. 2005

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

View full text Add to dashboard Cite

This paper presents continuum simulations of viscous polymer flow during nanoimprint lithography (NIL) for embossing tools having irregular spacings and sizes. Simulations varied non-uniform embossing tool geometry to distinguish geometric quantities governing cavity filling order, polymer peak deformation, and global mold filling times. A characteristic NIL velocity predicts cavity filling order. In general, small cavities fill more quickly than large cavities, while cavity spacing modulates polymer deformation mode. Individual cavity size, not total filling volume, dominates replication time, with large differences in individual cavity size resulting in non-uniform, squeeze flow filling. High density features can be modeled as a solid indenter in squeeze flow to accurately predict polymer flow and allow for optimization of wafer-scale replication. The present simulations make it possible to design imprint templates capable of distributing pressure evenly across the mold surface and facilitating symmetric polymer flow over large areas to prevent mold deformation and non-uniform residual layer thickness.

show abstract

Section: Resultssupporting

confidence: 88%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

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

Rowland

King

Sun

et al. 2005

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

View full text Add to dashboard Cite

show abstract

“…The problem is exacerbated when there are residual layer variations across the imprint field. [5,6] Variations in the thickness of the residual layer are typically found when solid film resists are imprinted with a mold that contains variations in feature density. In the presence of uneven residual layers, an accelerated lateral trimming occurs where the RIE breaks through the thinnest residual layer regions first.…”

mentioning

confidence: 99%

Residual Layer Self‐Removal in Imprint Lithography

Dumond¹,

Low²

2008

Advanced Materials

View full text Add to dashboard Cite

A new method for imprinting residual‐layer free polymer micro‐ and nano structures, particularly 3‐D structures with overhang, is demonstrated. This simple and versatile method induces self‐removal of the residual layer by controlled failure of the patterned film along the edges of the imprinted features. Pristine overhang structures down to ∼500 nm diameter are realized without exposure to plasma or chemical etchants.

show abstract

Analysis of laser/IR-assisted microembossing

Juang

Lee

et al. 2005

Polym. Eng. Sci.

View full text Add to dashboard Cite

To shorten the cycle time in conventional hot embossing, an infrared laser (laser/IR)-assisted microembossing process was investigated in this study. Since the laser/IR heats the substrate rapidly and locally, the heating and cooling time can be substantially reduced. Two different modes of IR embossing were tested. In one case, the polymer substrate was the IR-transparent poly(methyl methacrylate) (PMMA) and a carbon blackfilled epoxy mold was used. In the second case, the polymer substrate was an IR-absorbent PMMA, and an IR transparent epoxy mold was used. The experimental results showed that both a shorter cycle time and good replication accuracy could be achieved. A commercially available finite element (FEM) code, DEFORM™, was used for process simulation. The relationship between the penetration of radiation energy flux from the laser/IR heating source and temperature distribution inside the polymer substrate was considered in the simulation. The flow pattern observed in the experiments agreed well with the numerical simulation. However, the displacement curve showed a discrepancy. POLYM. ENG. SCI., 45: 661-668, 2005.

show abstract

Local mass transport and its effect on global pattern replication during hot embossing

Cited by 57 publications

References 6 publications

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

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

Residual Layer Self‐Removal in Imprint Lithography

Analysis of laser/IR-assisted microembossing

Contact Info

Product

Resources

About