title: Polyallylamine as an Adhesion Promoter for SU-8 Photoresist.
abstract: Resist lithography is an important microfabrication technique in the electronics industry. In this, patterns are transferred by irradiation onto a photosensitive polymer. SU-8 has emerged as a favorite photoresist for High Aspect Ratio (HAR) lithography, showing high chemical and mechanical stability and biocompatibility. Unfortunately, its poor adhesion to substrates is a drawback, with possible solutions being the use of low-viscosity SU-8, surface modification with a low molecular weight adsorbate like hexamethyldisilazane (HMDS), or a commercial adhesion promotion reagent. However, HMDS and the commercial reagent require surface dehydration and/or curing, and a modified form of SU-8 is not always desirable. Here, we demonstrate the use of a water-soluble, amine-containing polymer, polyallylamine (PAAm), which spontaneously adsorbs to silica surfaces, as a simple, easy-to-apply, and reactive adhesion promoter for SU-8. Conditions for the use of PAAm are explored, and the resulting materials are characterized by X-ray photoelectron spectroscopy (XPS), spectroscopic ellipsometry (SE), and wetting.
authors.affiliation: 1Department of Chemistry and Biochemistry,Brigham Young University,Provo,UT 84602,USA.
authors.forename: Shiladitya
authors.initials: S
authors.lastname: Chatterjee
authors.affiliation: 1Department of Chemistry and Biochemistry,Brigham Young University,Provo,UT 84602,USA.
authors.forename: George H
authors.initials: GH
authors.lastname: Major
authors.affiliation: 2Department of Information Technology,Brigham Young University,Provo,UT 84602,USA.
authors.forename: Barry M
authors.initials: BM
authors.lastname: Lunt
authors.affiliation: 1Department of Chemistry and Biochemistry,Brigham Young University,Provo,UT 84602,USA.
authors.forename: Massoud
authors.initials: M
authors.lastname: Kaykhaii
authors.affiliation: 1Department of Chemistry and Biochemistry,Brigham Young University,Provo,UT 84602,USA.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Linford
keywords: SU-8; adhesion; photoresist; polyallylamine