The reaction of acrylpimaric acid and several divinyl ether compounds, including 1,3-Bis(2-(vinyloxy)ethoxy)benzene,
2,2-bis(4-[2-(vinyloxy)ethoxy]phenyl)propane, and 1,4-Bis(2-(vinyloxy)ethoxy)benzene, can take place in the presence
of organic solvents to form novel ester acetal polymer with the average molecular weight of 4000-6000(M<sub>n</sub>) measured
by GPC. These polymers can be easily dissolved in common solvents and show high thermal stability. The ester acetal
polymers can be quickly acidolyzed at the presence of strong acid generated by PAG above 100<sup>o</sup>C and become easily
soluble in dilute aqueous base. Two-component positive photoresists can be formed by the ester acetal polymer and PAG.
The lithographic performance of the resist material composed of the ester acetal polymer and a sulfonium triflate PAG
was studied on i-line exposure instrument. Clear pattern with 2 &mgr;m resolution was obtained and the photosensitivity was