Study of PMMA recoveries on micrometric patterns replicated by nano-imprint lithography

Martin, C.; Ressier, Laurence; Peyrade, J.P.

doi:10.1016/s1386-9477(02)00859-7

Cited by 29 publications

(22 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Large amount of springback, which was reported earlier in both experiment [13] and simulation [26], is clearly observed where the stamp imprints. According to the previous studies, the relaxation of the compressive residual stress, the adhesive force between the stamp and the polymer film, the elastic deformation of the stamp or any combinations of these three may be responsible for this springback phenomenon [13,27]. Stress and density distributions will be discussed later in order to provide a plausible explanation for this.…”

Section: Resultssupporting

confidence: 77%

“…This spring-back phenomenon caused by elastic recovery is clearly displayed in figure 6(d) when the stamp is separated by 1.75 nm from the maximum indentation point. High density and stress areas disappear after the polymer film under the stamp pattern fully recovers from compression, which also supports that main causes of springpack are the residual compressive stress and density concentrations [13]. Moreover, the lower density area is found near the corner of the polymer pattern, which implies that fractures may be introduced from there when the pattern aspect ratio is much higher.…”

Section: Density and Stress Distribution Of The Polymer Filmsupporting

confidence: 55%

“…Through a number of studies performed to identify polymer deformation behavior [8][9][10][11][12][13], it has been revealed that the quality of pattern transfer can be significantly degraded because of several undesirable phenomena, such as lack of stamp cavity filling [8][9][10][11], limitation of residual layer thickness due to the unextruded polymer film [12], and recovery of the compressed polymer film [13]. These kinds of defects become significant and inevitable as a pattern aspect ratio grows higher and the thickness of the residual film becomes lower.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Molecular dynamics study of pattern transfer in nanoimprint lithography

Kang

Kim

2007

Tribol Lett

View full text Add to dashboard Cite

A molecular dynamics simulations model of nanoimprint lithography (NIL) is proposed in order to study the pattern transfer and its related phenomena. The proposed model is similar to a real NIL process imprinting an a-quartz stamp with a rectangular line pattern into an amorphous poly-(methylmethacrylate) (PMMA) film. The polymer deformation behavior and the adhesion and friction effects between the stamp and the polymer film are investigated and their dependency on the pattern aspect ratio is discussed. Force fields including bond, angle, torsion, van der Waals, and electrostatic potentials are used to describe intermolecular and intramolecular interacting forces. Nose´-Hoover thermostat is used to control the temperature of the polymer film and cell multipole method is adopted to treat long range interactions. The deformation of the polymer film is observed for two stamps having different aspect ratio patterns. The distributions of density and stress in the polymer film are calculated for the detail analysis of deformation behavior. For a high aspect ratio pattern (aspect ratio = 2.5, imprint depth = 8.0 nm), large amount of springback of the residual polymer film is observed, which is mainly due to the residual compressive stress left in the polymer film. However, for a low aspect ratio pattern (aspect ratio = 1.0, imprint depth = 3.0 nm), the springback is not observed. In addition, adhesion and friction forces are obtained by dividing the polymer film into subregions and calculating the interacting force between each subregion and the stamp. While the adhesion force is nearly constant regardless of the pattern aspect ratio, the friction force increases as the pattern aspect ratio grows, so the friction force becomes larger than the adhesion force when the pattern aspect ratio increases.

show abstract

Section: Resultssupporting

confidence: 77%

Section: Density and Stress Distribution Of The Polymer Filmsupporting

confidence: 55%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Molecular dynamics study of pattern transfer in nanoimprint lithography

Kang

Kim

2007

Tribol Lett

View full text Add to dashboard Cite

show abstract

“…Indentation into the thicker films resulted in dual peak deformation for high loads and single peak deformation for low loads. Residual stress release on demolding influenced final replicated feature size, a phenomenon also noted in [12].…”

Section: Introductionmentioning

confidence: 66%

Impact of polymer film thickness and cavity size on polymer flow during embossing : towards process design rules for nanoimprint lithography.

Schunk¹,

King

Sun³

et al. 2006

View full text Add to dashboard Cite

This paper presents continuum simulations of polymer flow during nanoimprint lithography (NIL). The simulations capture the underlying physics of polymer flow from the nanometer to millimeter length scale and examine geometry and thermophysical process quantities affecting cavity filling. Variations in embossing tool geometry and polymer film thickness during viscous flow distinguish different flow driving mechanisms. Three parameters can predict polymer deformation mode: cavity width to polymer thickness ratio, polymer supply ratio, and Capillary number. The ratio of cavity width to initial polymer film thickness determines vertically or laterally dominant deformation. The ratio of indenter width to residual film thickness measures polymer supply beneath the indenter which determines Stokes or squeeze flow. The local geometry ratios can predict a fill time based on laminar flow between plates, Stokes flow, or squeeze flow. Characteristic NIL capillary number based on geometry-dependent fill time distinguishes between capillary or viscous driven flows. The three parameters predict filling modes observed in published studies of NIL deformation over nanometer to millimeter length scales. The work seeks to establish process design rules for NIL and to provide tools for the rational design of NIL master templates, resist polymers, and process parameters. 4

show abstract

“…Such behavior has also been observed with homopolymers. [19] To overcome this problem, the internal stress of the resist should be allowed to relax to ambient conditions before molding; however, the corresponding creep rate of plastic polymers is quite long. Nevertheless, such relaxation can be induced in a reasonable time by raising the temperature.…”

Section: Resultsmentioning

confidence: 99%

Siloxane Copolymers for Nanoimprint Lithography

Choi¹,

Fu²,

Guo³

2006

Adv Funct Materials

View full text Add to dashboard Cite

Presented here is the novel use of thermoplastic siloxane copolymers as nanoimprint lithography (NIL) resists for 60 nm features. Two of the most critical steps of NIL are mold release and pattern transfer through dry etching. These require that the NIL resist have low surface energy and excellent dry‐etching resistance. Homopolymers traditionally used in NIL, such as polystyrene (PS) or poly(methyl methacrylate) (PMMA), generally cannot satisfy all these requirements as they exhibit polymer fracture and delamination during mold release and have poor etch resistance. A number of siloxane copolymers have been investigated for use as NIL resists, including poly(dimethylsiloxane)‐block‐polystyrene (PDMS‐b‐PS), poly(dimethylsiloxane)‐graft‐poly(methyl acrylate)‐co‐poly(isobornyl acrylate) (PDMS‐g‐PMA‐co‐PIA), and PDMS‐g‐PMMA. The presence of PDMS imparts the materials with many properties that are favorable for NIL, including low surface energy for easy mold release and high silicon content for chemical‐etch resistance—in particular, extremely low etch rates (comparable to PDMS) in oxygen plasma, to which organic polymers are quite susceptible. These properties give improved NIL results.

show abstract

Study of PMMA recoveries on micrometric patterns replicated by nano-imprint lithography

Cited by 29 publications

References 4 publications

Molecular dynamics study of pattern transfer in nanoimprint lithography

Molecular dynamics study of pattern transfer in nanoimprint lithography

Impact of polymer film thickness and cavity size on polymer flow during embossing : towards process design rules for nanoimprint lithography.

Siloxane Copolymers for Nanoimprint Lithography

Contact Info

Product

Resources

About