LF55GN Photosensitive Flexopolymer: A New Material for Ultrathick and High-Aspect-Ratio MEMS Fabrication

Author

Sayah, Abdeljalil ; Parashar, Virendra K. ; Gijs, Martin A M

Author_Institution

Swiss Fed. Inst. of Technol. Lausanne, Lausanne

Volume

16

Issue

3

fYear

2007

fDate

6/1/2007 12:00:00 AM

Firstpage

564

Lastpage

570

Abstract

A growing interest in the development of thick functional structures with high aspect ratio for microelectromechanical system (MEMS) applications has triggered the investigation of several polymer materials. This paper presents LF55GN flexopolymer material as a new negative-tone photoresist to fabricate ultrathick MEMS microstructures. Up to 4-mm-thick layers are obtained using a casting method in a single photolithography step. Standard UV illumination is used to polymerize such thick microstructures in less than 1 min and with an aspect ratio up to 27. We have fabricated microstructures on rigid, flexible, and stepped substrates. Using oblique UV exposure, tilted pillars are achieved with an angle of 25deg to the substrate normal. Due to the elastomeric nature of the LF55GN flexopolymer, the microstructures can be easily deformed without causing any stress-related problems.

Keywords

casting; micromachining; micromechanical devices; photoresists; polymers; LF55GN photosensitive flexopolymer; UV illumination; casting method; flexible substrates; high-aspect-ratio MEMS fabrication; microelectromechanical system; negative-tone photoresist; oblique UV exposure; photolithography; polymer materials; rigid substrates; stepped substrates; thick functional structures; ultrathick MEMS microstructures; Adhesives; Casting; Fabrication; Microelectromechanical systems; Micromechanical devices; Microstructure; Optical films; Polymers; Resists; Thermal stresses; Casting; LF55GN; flexopolymer; high aspect ratio; microfabrication;

fLanguage

English

Journal_Title

Microelectromechanical Systems, Journal of

Publisher

ieee

ISSN

1057-7157

Type

jour

DOI

10.1109/JMEMS.2007.896705

Filename

4276818