Negative-type Chemically Amplified Photosensitive Semi-alicyclic Polybenzoxazole via Acid-catalyzed Electrophilic Substitution

Abstract

ABSTRACT:A negative-type photosensitive semi-alicyclic polybenzoxazole (Nega-PSPABO) based on poly-(o-hydroxy amide) containing an adamantyl unit (PAHA) and oxybis(3,4-dihydroxymethyl)benzene (OBHB) as a cross-linker, and a photoacid generator, (5-propylsulfonyloxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl)acetonitrile (PTMA) has been developed. PAHA with a weight average molecular weight of 24,100 was prepared from 1,3-adamantanedicarbonyl chloride (ADC) and 4,4 0 -(hexafluoroisopropylidene)bis(o-aminophenol) (6FAP) in the presence of lithium chloride in N-methyl pyrrolidinone (NMP) at 0 C for 12 h. The photosensitive polymer based on 85 wt % PAHA, 10 wt % OBHB, and 5 wt % PTMA showed a sensitivity of D 0:5 ¼ 14:4 mJ/cm 2 and a contrast of 2.4 when it was exposed to a 365 nm light (i-line) and developed with a 2.38 wt % aqueous tetramethylammonium hydroxide solution (TMAHaq) at 25 C. A fine negative image of 7 mm line-and-space pattern was also printed in the film which was exposed to 80 mJ/cm 2 of i-line by contact-printing mode. The negative image in PAHA was converted to the corresponding PABO pattern image by thermal treatment without pattern deformation. The average refractive index of Nega-PSPABO was 1.542 from which the dielectric constant estimated was 2.62 at 1 MHz.

Facile Synthesis of Photosensitive Poly(semi-alicyclic benzoxazole) and Subsequent Low-Temperature Cyclization of Poly(o-hydroxy amide)

“…We have reported the synthesis of semi-alicyclic PHA (PAHA) with high transparency (99% T at 365 nm) and the corresponding PBO (PABO) having a low dielectric constant ( ) 2.55). 8 PAHA was then employed as both (a) positivetype PSPBO consisting of PAHA, 1,3,5-tris[(2-vinyloxy)ethoxy]benzene (TVEB) as an acidolytic de-cross-linker, and diphenyliodonium 9,10-dimethoxyanthracene-2-sulfonate (DIAS) as a photoacid generator (PAG) 8 and (b) negative-type PSPBO based on PAHA, oxybis (3,4-dihydroxymethyl)benzene (OBHB) as a cross-linker, and (5-propylsulfonyloxyimino-5H-thiophen-2ylidene)-(2-methylphenyl)acetonitrile (PTMA) as a PAG 9 in chemical amplification systems. Because of the introduction of an adamantyl unit in the polymer, the dielectric constant of PABO effectively lowered because of the decreasing molecular density and conjugation in the main chain.…”

Photosensitive Poly(benzoxazole) Based on Poly(o-hydroxy amide), Dissolution Inhibitor, Thermoacid Generator, and Photoacid Generator

“…The conventional PSPBO based on DNQ, however, possesses low sensitivity (>100 mJ/cm 2 ) and a strong absorbance at 365 nm, and is difficult to use for thick patterns. To overcome these problems, a chemically amplified technique was introduced to develop PSPBOs coupled with a photoacid generator (PAG), 7 for which 9,9-bis(4-tert-butoxycarbonyloxyphenyl)fluorene (tBocBHF) was used as a dissolution inhibitor (DI). 8 This three-component, positive-type, alkaline-developable PSPBO showed the sensitivity and contrast of 34 mJ/cm 2 and 5.8, respectively with i-line exposure, to produce a 20 mm image in 10 mm thick film.…”

A Negative Type Photosensitive Polymer Based on Poly(naphthylene ether), a Cross-Linker, and a Photoacid Generator with Low Dielectric Constant

“…As substitutes of PIs, there are several matrix polymers such as poly(benzoxazole)s (PBOs) [8][9][10] and poly-(phenylene ether)s (PPEs), 11 which are successfully applied to the photosensitive polymers. Poly(2,6-dihydroxy-1,5-naphthylene) (PDHN) exhibits low " of 2.8, and have been applied to both negative- 12 and positive-type 13 photosensitive polymers because of moderate dissolution behavior in an alkaline developer.…”