New synthetic route for photosensitive poly(benzoxazole)

Abstract

A new positive working photosensitive poly(benzoxazole) (PBO) precursor based on poly(o‐hydroxyazomethine) (3) and 1‐{1,1‐bis[4‐(2‐diazo‐1‐(2H)naphthalenone‐5‐sulfonyloxy)phenyl]ethyl}‐4‐{1‐[4‐(2‐diazo‐1(2H)naphthalenone‐5‐sulfonyloxy)phenyl]methylethyl}benzene (S‐DNQ) as a photosensitive compound was developed. 3 was prepared by the condensation of 2,2‐bis(3‐amino‐4‐hydroxyphenyl)hexafluoropropane with isophthalaldehyde in 1‐methyl‐2‐pyrrolidinone/toluene under azeotropic conditions. The photosensitive PBO precursor containing 30 wt % S‐DNQ showed a sensitivity of 120 mJ cm−2 and a contrast of 2.2 when it was exposed to 436‐nm light and developed with a 2.38 wt % aqueous tetramethylammonium hydroxide solution at room temperature. A fine positive image featuring 10‐μm line and space patterns was observed on the film of the photoresist exposed to 200 mJ cm−2 ultraviolet light at 436 nm by the contact mode. The positive image was successfully converted into the PBO pattern by a thermal treatment. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3399–3405, 2002

Photosensitive Poly(benzoxazole) via Poly(o-hydroxy azomethine) II. Environmentally Benign Process in Ethyl Lactate

“…In the IR spectrum, the characteristic absorption at 1627 cm À1 due to oxazole ring was appeared, and the absorption at 3421 cm À1 corresponding to the hydroxyl group in PHAM was disappeared, indicating a transformation of PHAM into the corresponding PBO. 15 In the same curing treatment, the photosensitive PHAM film containing S-DNQ on silicon wafer was transformed into the PBO film, where no crucial deformation of the image is observed as shown in Figure 5.…”

“…The film spincast on a PI-coating-silicon-wafer was prebaked at 80 C for 1 min, and then exposed to a 436 nm light (g-line, 300 mJ/cm 2 ) because the optical absorption edge of PHAM film reaches around 420 nm. 15 The dissolution rate in both the exposed and unexposed area was estimated from the each film thickness after development. The results are shown in Figure 1.…”

“…Recently, a novel route of formulation for PSPBOs has been reported, based on poly(o-hydroxyazomethine)s (PHAMs) and diazonaphothoquinones (DNQs). 15 Compared to the synthesis of PHA derived from dicarboxylic active diester and bis(o-aminophenol) derivatives, PHAM is an attractive precursor for PSPBO because of its facile synthesis from dialdehyde and bis(o-aminophenol) derivatives, and the leaving group in the synthesis of PHAM is just water, environmentally advantageous to phenol in PHA synthesis. Furthermore, the direct photosensitive polymer formulation from the polymerization solution is possible by simply adding DNQ.…”

Positive-type Alkaline Developable Photosensitive Branched Polyamides with Low Degree of Branching and Diazonaphthoquinone as a Photosensitive Compound

“…19 Similar to the novolac resin used in the commercial g-line or i-line photoresists, the polymer matrix bearing phenolic hydroxy groups can be inhibited by the addition of DNQ photoactive compound. [20][21][22][23][24][25][26][27][28] In order to introduce phenolic hydroxy groups into the branched polyamides obtained, the end-modification of the amino groups was carried out by using 4-hydroxy benzoic acid. Prior to the end-modification of polymers, we initially studied the reaction of aniline and 4-hydroxy benzoic acid in the presence of TPP/Py to determine whether the desired model compound 3 was formed in quantitative yield to constitute a polymer-forming reaction and to confirm the structure of polymers (Scheme 3).…”

A Novel Low Temperature Curable Photosensitive Polybenzoxazole

“…[DOI 10.1295/polymj.37.517] KEY WORDS Photosensitive Polybenzoxazole / Low Temperature Solid-phase Cyclization / i-Line Lithography / Poly(o-hydroxyamine) / Alkaline Developer / Thermoacid Generator / Polybenzoxazoles (PBOs) have been used as protection and insulation layers for very large scale integration circuits (VLSI) and multi-chip modules for computers owing to their high thermal stability and excellent mechanical property. [1][2][3][4] Photosensitive PBOs (PSPBOs) [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] have been developed to simplify the processing steps because phenolic hydroxyl groups in precursors of PBOs provide adequate solubility toward an aqueous alkaline developer. Up to now PSPBO based on the poly(o-hydroxyamide) (PHA-6F) derived from 6FAP and 4,4 0 -oxybis(benzoic acid) derivatives 22,23 with a photosensitive compound has been widely used, in which the image of PHA-6F is finally converted into that of PBO by thermal treatment at 350…”