| Abstract: | Microstructures with characteristic dimensions down to one micrometer and structural heights of several hundred micrometers are produced by deep-etch synchrotron radiation lithography using poly-(methyl methacrylate)(PMMA) as resist. In the present paper the details of the process are described. Microstructures without defects caused by stress corrosion are produced by polymerization of a methyl methacrylate base casting resin containing 1% of a cross-linking dimethacrylate onto a metallic base plate and developing the irradiated parts in solvents with solubility parameters at the periphery of the solubility range of PMMA. In this case the structural tolerances of the microstructures are less than 0.05 μm per 100 μm structural height. Measurements of the dissolution rate and the molecular weight and calculations of the absorbed dose show that the irradiated cross-linked PMMA is only developable if the absorbed dose is greater than 1.6 kJ which yields a molecular weight MW of 14 000 g/mol. |
