Nanoimprint II

NIL Technology sells stamps for nanoimprint lithography (NIL) and provides imprint services. Stamps made in Siliocn, Quartz, and Nickel are offered. Large area homogeneous imprints are ensured with NIL Technology stamps by a patent pending stamp technology. The stamps are produced with customer defined stamp patterns. Large area homogeneous imprints (patent pending) Standard stamp structures down to 20 nm Minimum stamp structure size below 20 nm Up to 200 mm wafer stamps Stamp materials: Silicon, Quartz, and Nickel NIL technology stamps can be used in many different applications such as (but not limited to): Consistent energy, e.g. solar cells and fuel cells, Batteries, Micro and nano fluidics, Light emitting diodes and lasers; Life science, e.g. controlled cell behaviour surfaces and lab-on-a-chip systems; Optics, e.g. gratings, integrated optical devices, SERS substrates, and anti reflective structures; Radio frequency (RF) components Data storage, e.g. optical media, magnetic media, and holograms; Security, e.g. holograms; CPU ’ s and memory. Interested partners are invited to join collaborations with NIL Technology on developing products benefiting from nanostructures and NIL.

Limitations of NIL

Feather Depth Variation for Complex Patterns

Combined Nanoimprint and Photolithography

Residual Resist Removal in CNP

Eliminates Residual-removal by O 2 RIE

Step and Flash Imprint Lithography

Solvent Assisted Imprint Solvent vapor treatment

Solvent Assisted Imprint

Room Temperature Imprint

Pattern Uniformity Control

Comparison

Conclusions Use of free volume contraction and plastic deformation Room temperature processing No mold surface treatment Step and repeat Multiple imprinting Suitability for OLEDs and OTFTs A high pressure (30~100 bars)

Low Pressure Imprinting Use of a flexible film mold Conformal contact of protruding parts of the mold with the underlying substrate Sequential, not parallel, imprinting of pattern features (stiff mold; all the pattern on the surface to penetrate into polymer)

Low-Pressure Hot Imprinting

Poly (urethane acrylate) molds Low-pressure room temperature imprinting

Conclusions for Low-Pressure Room Temperature Imprinting Requirements: Low pressure (2~3 bars) Low temperature (room T) Step-and-repeat Easy and clean de-molding Variable fill factor Easy mold replication Multilayer alignment

Other Non-Conventional Methods 1. By capillary force Capillary Force Lithography (CFL) Soft molding 2. By dewetting force Anisotropic dewetting Selective dewetting 3. By self-organization Self-organized CFL Self-organized buckling

Capillary Force Lithography: Concept

Kinetics of CFL (I)

Conclusions Use of thermal capillary Good pattern fidelity Direct exposure of substrate surface No application of pressure Minimum feature size down to ~ 100 nm When pattern size gets smaller than 100 nm, the max aspect ratio of the gap attainable is less than 0.25 (may be broken during detachment of mold).

Soft Molding: Conclusions Use of solutal capillarity Inexpensive method Three-dimensional patterning Large-area patterning (~ 4 inch wafer) No fidelity problem Direct pattern transfer to a substrate

Patterning by Dewetting – Historical Background Anisotropic and Selective Dewtting

Anisotropic spinodal dewetting as a route to self-assembly of patterned surfaces A. M. Higgins & R. A. L. Jones Nature 404, (2000).

Anisotropic Dewetting: Theory

Anisotropic Dewetting: Conclusions Dewetting of thin polymer films Anisotropic dewetting by mold confimement Block vs Fingering pattern Formation of ordered polymer pattern Reduced wavelength due to confinement

Selective Dewetting: Concept

Selective Dewetting: Result

Selective Dewetting: Conclusions Selective Dewetting by Mold Nucleation General purpose patterning by selective dewetting Pattern size control by dewetting time Controllability to the level of 10 nm scale

Patterning by Self-Organization Self-organized polymeric microstructure (SOM) Self-organized patterns by anisotropic buckling

Historical Background Use of chemical forces such as self-assembled monolayers (SAM) Control of chemical or structural properties, chemical sensing, catalysis, etc. Ordering on a nanometer scale Difficulty in large-area applications Use of physical driving forces such as capillarity Control of microstructures of surfaces, ex) patterning, photonic crystals, microreactor, etc. Ordering on a micrometer scale No difficulty in large-area applications

Self-Organized Microstructure: Concept