Photoimageable composition

Abstract

The use of photoacid generators including an alkoxyphenylphenyliodonium salt and / or bis(t-butylphenyl)iodonium salt in a photoimageable composition helps improve resolution. Suitable photoimageable compositions includes: (a) a multifunctional polymeric epoxy resin that is dissolved in an organic solvent wherein the epoxy resin comprises oligomers of bisphenyl A that is quantitatively protected by glycidyl ether and wherein the oligomers have an average functionality that ranges from about 3 to 12; and a photoacid generator comprising an alkoxyphenylphenyliodonium salt and / or bis(t-butylphenyl)iodonium salt. Preferred alkoxyphenylphenyliodonium salts include 4-octyloxyphenyl phenyliodonium hexafluoroantimonate and 4-methoxyphenyl phenyliodonium hexafluoroantimonate. The photoimageable composition is particularly suited for producing high aspect ration microstructure.

Description

[0001] This application is a divisional application of U.S. patent application Ser. No. 10 / 125,134, filed Apr. 17, 2002, entitled PHOTOIMAGEABLE COMPOSITION by Paul Dentinger, et al. (Attorney Docket No.: SAND-01082US0).[0002] This invention was made with Government support under Contract No. DE-AC04-94AL85000 awarded by the U.S. Department of Energy to Sandia Corporation. The Government has certain rights to the invention.FIELD OF THE INVENTION [0003] The present invention is directed to photoimageable compositions of improved composition that exhibit superior resolution. The invention is also directed to methods of fabricating microstructure metal parts using the photoimageable composition and particularly to fabricating microstructures having non-linear features. BACKGROUND OF THE INVENTION [0004] There are a variety of applications for which thick-film lithography may prove advantageous or even necessary. For instance, thick-film lithography may be used as a plating mold to crea...

AI Technical Summary

Benefits of technology

"The invention is about improving the resolution of a photoimageable composition by using alkoxyphenylphenyliodonium salt and / or bis(t-butylphenyl)iodonium salt photoacid generators. The composition includes a multifunctional polymeric epoxy resin and a photoacid generator. The use of these generators helps to create a more precise image when using a developer to remove non-exposed parts of the composition. The invention also includes a method for fabricating microstructures and metal structures using this composition."

Problems solved by technology

In addition, the low run-out synchrotron sources produces sharp side walls, but synchrotron sources are scarce and expensive.

However, these materials suffer from several drawbacks when used in thick (≧50 μm) films.

In addition, DNQ requires water for proper formation of the soluble, photoproduced acid which leads to requiring long reabsorption times after the initial post-apply bake (PAB).

Finally novolac materials have a tendency to crack, which is particularly problematic for thick films.

However, drawbacks of this resist include solvent development, shrinkage of the cured material, and when used in very thick films, absorption of radiation can result in degraded sidewall profiles.

These drawbacks result in poor resolution.

The cured resist is also difficult to remove.

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