Nanoscale photolithography

Abstract

A simple and practical method that can reduce the feature size of a patterned structure bearing surface hydroxyl groups is described. The patterned structure can be obtained by any patterning technologies, such as photo-lithography, e-beam lithography, nano-imprinting lithography. The method includes: (1) initially converting the hydroxyl or silanol-rich surface into an amine-rich surface with the treatment of an amine agent, preferably a cyclic compound; (2) coating an epoxy material on the top of the patterned structure; (3) forming an extra layer when applied heat via a surface-initiated polymerization; (4) applying an amine coupling agent to regenerate the amine-rich surface; (5) coating an epoxy material on the top of the patterned structure to form the next layer; (6) repeating step 4 and 5 to form multiple layers; ; This method allows the fabrication of feature sizes of various patterns and contact holes that are difficult to reach by conventional lithographic methods.

Description

[0001] Cross references to related patent applications [0002] none [0003] Statement Regarding Federally Sponsored Research [0004] none Background technique [0005] As the dimensions of fabricated structures reach the nanoscale domain, photolithography begins to face several technical, economical and physical challenges. For example, photolithography suffers from physical constraints due to wavelength diffraction problems that prevent fabrication of ultra-small structures. Additionally, equipment and facilities are becoming prohibitively expensive. Developing techniques such as NIL and SFIL molding techniques appear to offer low-cost, high-throughput methods for patterning large areas; however, molding requires initial master molds, which are typically made by lithographic methods and can Subject to some traditional restrictions. Another method based on electron beam lithography called "molecular rulers" enables the creation of metallic structures as small as 30nm; ...

AI Technical Summary

Problems solved by technology

For example, photolithography encounters physical constraints due to wavelength diffraction problems that hinder the fabrication of ultra-small structures

Also, equipment and facilities are becoming prohibitively expensive

Developing techniques such as NIL and SFIL molding techniques appear to offer low-cost, high-throughput methods for patterning large areas; however, molding requires initial master molds, which are typically made by lithographic methods and can limited by some traditions

Another method based on electron beam lithography called "molecular rulers" enables the creation of metallic structures as small as 30nm; however, this technique is time-consuming and laborious as it relies on layer-by-layer deposition

A similar approach involves forming polymer brushes on different types of patterned polymers by atom transfer radical polymerization (ATRP) to control the size of imprinted structures, but this method is slower (4 to 16 Å depending on the monomer used). Hours)

Another approach is the sealing and oxidation shrinking method, which can create sub-10nm channels; however, this method requires expensive laser equipment and high oxidation temperature

Yet another technique, called Self-improvement by Liquefaction (SPEL), has been used to create small nanostructures; however, it requires fully conformal contact between the guide plate and its target, which is difficult to achieve, and the size of the resulting structure is achieved by aggregation Material backflow control, it is difficult to control accurately

Finally, shadow evaporation was also used to reduce the grating gap size down to 10nm, but this has not been shown to produce sharp profiles

[0006] Therefore, there remains an unmet need for effective feature size reduction that is difficult to achieve with conventional photolithographic methods

Images