Industrial Technology Research Institute

Chao H Tseng

Pao-Ju Hsieh

Hua-Chi Cheng

A positive photoresist composition is disclosed which comprises a photosensitive compound, a phenolic resin, and an organic solvent. The phenolic resin is prepared from a monomeric composition comprises formaldehyde and a mixture of phenol monomers. The mixture of phenol monomers comprises: (a) no more than 98 mole percent of a mixture of monohydroxy phenols, the mixture of monohydroxy phenols comprises: (I) about 50.about.80 mole percent of meta-methylphenol; (ii) about 10.about.30 mole percent of 2,5-dimethylphenol; and (iii) about 10.about.40 mole percent of 2,3,5-trimethylphenol; and (b) at least 2 mol percent of at least one polyhydroxybenzene which is presented by the following formula: ##STR1## wherein n is an integer of 1 or 2. Preferably, the polyhydroxybenzene is a mixture of trihydroxybenzene and dihydroxybenzene in a molar ratio of about 40 to 60. The photoresist composition can be developed using a weak basic solution which causes images of sharp contrast to be developed; it can also be advantageously used in making color filters for use in color liquid crystal displays in a multiple development process in conjunction with an electrodeposition lithography.

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Taipei, Taiwan

Chao H Tseng