Journal of Vacuum Science & Technology B, Vol.20, No.6, 2968-2972, 2002
Partially hydrogenated poly(vinyl phenol) based photoresist for near UV, high aspect ratio micromachining
A negative resist platform based on a low Mw epoxy novolac polymer; partially hydrogenated poly(vinyl phenol)s and suitable onium salt photoacid generators is presented and evaluated for high aspect ratio micromachining. The high content of hydroxyl groups in this resist system allows development in standard aqueous base solutions (TMAH 0.26 N). The effects of material parameters such as the degree of poly(vinyl phenol) hydrogenation and the onium salt hydrophobicity on the development process are examined. The cross-linked areas of this resist can be easily removed by commercial wet photoresist strippers after processing. Experimental data demonstrate a promising lithographic performance with an aspect ratio of 7:1 for 5 mum closely spaced lines under exposure at 365 nm.