Micromachining applications of a high resolution ultrathick photoresist

This study has demonstrated high aspect ratio and high resolution near-ultraviolet photolithography on ultrathick SU-8 resist films. The process is simple and can resolve 20μm features in 200μm films. The resist shows very high thermal and chemical stability and is therefore suitable for prolonged plasma etching and metal plating. Application of this resist for fabricating micro-octupole scanners for electron microcolumns is demonstrated. The results show that the plating process using SU-8 resist can be a cost-effective alternative to the LIGA (lithographie, galvanoformung, abformung) process. Another potential application is the fabrication of LIGA masks.