MICROFABRICATION USING SYNCHROTRON-RADIATION

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-dimens ional pattern is accurately transferred from a mask into a resist mate rial by chemical changes induced by the radiation. Subsequent electrof orming and moulding processes are used to manufacture microstructures from metals, plastics and ceramics. This process, known as LIGA (Litho graphie, Galvanoformung, and Abformung), first developed in Germany, i s based on a combination of lithography, electroforming and replicatio n processes. The development of the LIGA process for the fabrication o f a wide range of precision microstructures has been stimulated by the increasing use of synchrotron radiation sources for lithography. Appl ications for microstructures exist in many sectors of industry. These include chemical and process engineering, biomedical instrumentation, automotive and aerospace technology, environmental monitoring and info rmation technology. Emphasis is placed on three main areas, micromecha nics, micro-optics and microfluidics, which are emerging with the wide st range of industrial applications.This paper reviews the progress be ing made in microfabrication technology using x-ray beam lithography a nd the LIGA process. It includes a description of synchrotron radiatio n, storage ring sources, the fabrication processes, applications and p otential markets. Reference is also made to European networks and R&D activity worldwide.