Method and apparatus for rapid imprint lithography

Abstract

In accordance with the invention, a mold for imprinting a patterned region by imprint lithography is provided with a peripheral groove around the patterned region. The groove is connected, as by channels through the mold, to a switchable source for gas removal to prevent bubbles and for the application of pressurized gas to separate the mold and substrate.In use, the mold is disposed adjacent the moldable surface and gas is withdrawn from the patterned region through the groove as the mold is pressed toward and into the moldable surface. At or near the end of the imprinting, the process is switched from removal of gas to the application of pressurized gas. The pressurized gas passes through the groove and separates or facilitates separation of the mold and the moldable surface.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of U.S. Provisional Application Ser. No. 60 / 867,515 of the same title filed by Wei Zhang on Nov. 28, 2006 and which is incorporated herein by reference.FIELD OF THE INVENTION[0002]This invention relates to methods and apparatus for performing imprint lithography. It is particularly useful for providing high resolution microscale or nanoscale imprint lithography at high speed.BACKGROUND OF THE INVENTION[0003]Lithography is a key process in the fabrication of semiconductor integrated circuits and many optical, magnetic, biological and micromechanical devices. Lithography creates a pattern on a thin film carried on a substrate so that, in subsequent process steps, the pattern can be replicated in the substrate or in another material that is added onto the substrate.[0004]Conventional lithography, referred to as photolithography, involves applying a thin film of photosensitive resist to a substrate, exposin...

AI Technical Summary

Benefits of technology

"The invention provides a mold for imprinting a patterned region using imprint lithography. The mold has a peripheral groove around the patterned region that is connected to a switchable fluid source for applying pressurized fluid to separate the mold and substrate. The same grooves and channels can be used for gas removal to prevent bubbles. The mold is placed near the moldable surface and gas is removed through the groove and channels as the mold is pressed onto the surface. The process is then switched to applying pressurized fluid to separate the mold and the moldable surface. The technical effect is to improve the accuracy and precision of patterned imprinting."

Problems solved by technology

Unfortunately, the resolution of patterns produced by photolithography is limited by the wavelength of the exposing radiation.

Moreover, as pattern features become smaller, increasingly expensive shorter wavelength equipment is required.

A potential limitation on the rate of high speed manufacturing using imprint lithography is the presence of gas between the mold and the moldable film.

Pressing the mold too rapidly can entrap gas bubbles in tiny recessed regions, deteriorating the resolution of the imprinted pattern.

A second limitation is the separation of the mold and the imprinted substrate.

The separation step thus limits throughput of imprinting.

Furthermore, this conventional separation may cause cracking at the edge of the mold or substrate.

It thus, contributes to mold wear, increases operating cost, and limits throughput.

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