Method of patterning a device

Abstract

A photoresist layer comprising a fluorinated photoresist material is formed on a device substrate and exposed to patterned radiation. The exposed photoresist layer is contacted with a developing agent to remove a portion of the exposed photoresist layer in accordance with the patterned light, thereby forming a developed structure having a first pattern of photoresist covering the substrate and a complementary second pattern of uncovered substrate corresponding to the removed portion of photoresist, the developing agent comprising a mixture of first and second fluorinated solvents, wherein at least one of the first and second solvents is a hydrofluoroether. The developed structure is treated to form a treated structure. The treated structure is contacted with a stripping agent to remove the first pattern of photoresist, the stripping agent comprising at least the first or second solvent in a concentration different from the developing agent.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of U.S. Provisional Application No. 61 / 815,465, filed on Apr. 24, 2013, the entire disclosure of which is hereby incorporated herein by reference. This application is also related to U.S. patent application Ser. No. ______ entitled “Method of Patterning a Device,” Attorney Docket No. 16480.0012USU2, filed on even date herewith.STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH OR DEVELOPMENT[0002]This invention was made with Government support under SBIR Phase II Grant No. 1058509 awarded by the National Science Foundation (NSF). The government may have certain rights in the invention.BACKGROUND[0003]1. Field of the Invention[0004]The present invention relates to the use of fluorinated solvents and solvent blends for processing fluorinated photoresists. Such solvents and photoresists are particularly useful for patterning organic electronic and biological materials.[0005]2. Discussion of Related Art[0006]...

AI Technical Summary

Benefits of technology

The patent describes the use of a mixture of solvents in a developing and stripping solution to improve development and recycling performance in a photolithographic process. By using different ratios of the solvents, the solution becomes more effective in removing the photopolymer and reducing waste. This simplifies the recycling process and reduces manufacturing costs, while also minimizing the impact on the environment.

Problems solved by technology

Although the use of photoresists is routine in traditional electronic devices based on inorganic materials, photolithography has been difficult to achieve for devices using organic materials, thereby hindering the development of devices based on these materials.

Specifically, organic materials are much less resistant to the solvents that are used for conventional photolithography, as well as to the intense light sources that are sometimes used in these processes, with the result that conventional lithographic solvents and processes tend to degrade organic electronics.

Although there have been various attempts to overcome these problems, e.g., by ink jet printing or shadow mask deposition, these alternative methods do not produce the same results as would be obtained with successful photolithography.

Specifically, neither ink jet printing nor shadow mask deposition can achieve the fine pattern resolutions that can be obtained by conventional lithography, with ink-jet printing limited to resolutions of approximately 10-20 μm and shadow mask deposition to resolutions of about 25-30 μm.

Although these disclosures demonstrate good progress, many of the more useful fluorinated solvents can be expensive.

Distillation is mentioned, but it is noted that sufficient purity is difficult to achieve with distiller sizes typically used in a normal cleaning apparatus.

Although the recycling method of Nakazato may help purify the fluorine-based solvents of other materials, it will not separate different fluorinated solvents.

Ishiduka does not disclose using hydrofluoroether solvents as developers nor recycling mixtures of developer and stripping solvents.

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