Chemically Amplified Photosensitive Poly(benzoxazole)

A novel chemically amplified photosensitive poly (benzoxazole) (PBO) precursor based on partially tert-buthoxycarbonylated (t-BOC) poly (o-hydroxyamide) having norbornene end-capping groups 5 and diphenyliodonium-9, 10-dimethoxyantracene-2-sulfonate (DIAS) as a photo-acid generator has been developed. The resist showed a sensitivity of 60 mJ cm-2 and a contrast of 2.5 when it was exposed to 365 nm light, followed by post-baking at 120°C for 5min and developing with 2.38 wt% aqueous tetramethylammonium hydroxide (TMAH) solution at 25°C. A fine positive image featuring 10μm line and space patterns was obtained on the film exposed to 100 mJ cm-2 of UV-light at 365 nm by the contact mode. By heat treatment at 350°C for 1h, this positive image gave the cross-linked PBO retaining its original shape that indicated high durability during thermal process.