Microfabrication using synchrotron radiation

Abstract

The realization of precision deep microstructures requires high-energy, intense parallel beams of x-rays from synchrotron radiation sources and novel process technology. Deep x-ray lithography with synchrotron radiation is basically a shadow printing process in which a two-dimensional pattern is accurately transferred from a mask into a resist material by chemical changes induced by the radiation. Subsequent electroforming and moulding processes are used to manufacture microstructures from metals, plastics and ceramics. This process, known as LIGA (LIthographie, Galvanoformung, and Abformung), first developed in Germany, is based on a combination of lithography, electroforming and replication processes. The development of the LIGA process for the fabrication of a wide range of precision microstructures has been stimulated by the increasing use of synchrotron radiation sources for lithography.Applications for microstructures exist in many sectors of industry. These include chemical and process engineering, biomedical instrumentation, automotive and aerospace technology, environmental monitoring and information technology. Emphasis is placed on three main areas, micromechanics, micro-optics and microfluidics, which are emerging with the widest range of industrial applications.This paper reviews the progress being made in microfabrication technology using x-ray beam lithography and the LIGA process. It includes a description of synchrotron radiation, storage ring sources, the fabrication processes, applications and potential markets. Reference is also made to European networks and R&D activity worldwide.

Filling transition for a wedge

“…However, e.g., in the context of structured semiconductor surfaces [17][18][19], microfluidics [20][21][22][23][24], and templates for the selfassembly of small particles [25][26][27] highly regular nonflat lateral surface structures can be produced. But both the theoretical understanding of the local wetting phenomena in such structures [28][29][30][31][32][33][34][35][36][37][38][39][40][41][42] as well as corresponding experimental investigations [43,44] are still in their infancies [45].…”

Wetting films on chemically heterogeneous substrates

“…A large variety of experimental techniques has emerged which allows one to endow solid substrates with stable, persistent, and well-defined lateral patterns of geometrical or chemical nature or a combination thereof [1][2][3][4][5][6]. The spatial extension of these regular structures ranges from the µm scale down to nm.…”

Critical Casimir forces between planar and crenellated surfaces

“…[19][20][21][22][23]). Critical Casimir forces for chemically structured confinements have been studied theoretically [24][25][26][27][28][29][30][31] as well as in experiments with colloidal particles [32,33].…”