Microfabrication processes on cylindrical substrates – Part I: Material deposition and removal

Cylindrical substrates offer a unique geometry for microfabrication processing. This paper describes methods for depositing and removing materials from cylinders ranging in diameter from 85 μm to 3000 μm. Rotary-sputtered thin films are shown to have predictable deposition rates and excellent longitudinal and radial uniformity. Dip-coated films suffer from low radial uniformity and must be individually characterized to predetermine the film thickness applied for a given withdrawal rate. Etch processes display predictable etch rates similar to those for planar substrates.