A NEW DRY ETCHING METHOD WITH THE HIGH ETCHING RATE FOR PATTERNING CROSS-LINKED SU-8 THICK FILMS
Jingning Han – Zhifu Yin – Helin Zou – Wenqiang Wang – Jianbo Feng
Photo sensitive polymer SU-8, owing to its excellent mechanical properties and dielectric properties on polymerization, is widely used in MEMS device fabrications. However, the removing, stripping or re-patterning of the cross-linked SU-8 is a difficult issue. In this paper, CF4O2 gas mixture provided by a plasma asher equipment was used for the patterning of cross-linked SU-8 material. The RF power, the temperature of the substrate holder, chamber pressure and gas concentration were optimized for the cross-linked SU-8 etching process. When the CF4O2 mixture contains about 5 % CF4 by volume, the etching rate can be reached at 5.2 μm/min}$.
Keywords: dry etching, plasma, SU-8 photoresist, etching rate