Positive-Working Photosensitive Alkaline-Developable Polyimide Precursor Based on Semi-Alicyclic Poly(amide acid),Vinyl Ether Crosslinker,and a Photoacid Generator

摘要

A positive-working photosensitive polyimide based on semi-alicyclic poly(amide acid) (PAA),1,1,1-tris(4-[2-(vinyloxy)ethoxy]phenyl)ethane (TVPE) as a crosslinking dissolution inhibitor and a photoacid generator has been developed.PAA was prepared from pyromellitic dianhydride and alicyclic diamine in N,N-dimethylacetamide (DMAc),which has excellent transparency above 365 nm and good solubility for 1 % sodium carbonate aqueous solution (aq.).The resist from the polymerization solution was formulated with photosensitive additives without isolation of PAA.A 23 um thick film of the PSPI precursor system containing 25 wt% TVPE,5 wt% PAG exhibited a sensitivity of 160 mJ/cm2 and contrast of 1.3 when it was exposed to broadband UV light followed by development in a 1 % sodium carbonate aq.at room temperature.A positive image featuring 40 mu m line and space patterns was observed by the contact mode.