Fabrication process of color filters using pigmented photoresists

The fabrication process of color filters produced with a series of new pigmented photoresists (CX513RGB) and their performance are described. The novel resist materials offer excellent contrast, good film uniformity and a stable shelf life exceeding 6 months, which was achieved by optimization of the amount and the molecular weight of a proprietary pigment dispersant. The development conditions of the pigmented resists were found to be influenced by their adhesion to the substrate materials (glass, chromium oxide and pixels). Dissolution type development was observed for prebake temperatures below 135 degrees C or when developers with higher tetramethyl ammonium hydroxide (TMAH) concentrations were used. The desired overcut pattern profiles were obtained when development limes ranged from 60-180s. CX513RGB resists obey the "reciprocity law" over 3 mW/cm(2) and thus the resist sensitivity is not affected by the irradiation power generated by conventional mask aligners (15-20 mW/cm(2)).