AR-P 8100 (Phoenix 81) thermal pattern-able positive resist
High-contrast, thermal pattern-able resist for integrated circuit and holographic structure
Patterning of PPA with photolithography
PPA layers can also be structured directly by means of photolithography. Irradiation with UV-light of a wave- length of < 300 nm results in a cleavage of the polymer chains to form volatile components.
By adding PAGs (photo acid generators), the photosensitivity can be significantly increased. The exposure releases acid in situ which then decomposes the PPA layer at 95 - 100 °C during the subsequent PEB (positive development).
The thermally induced, solvent-free development step proceeds almost completely. Cross-linking processes which are also induced by UV-exposure may however cause a thin, only a few nanometres thick residual resist layer. A residue-free substrate surface is obtained after addition of a short plasma etching step.