PHOTORESIST COMPOSITION AND METHOD FOR MANUFACTURING A DISPLAY SUBSTRATE USING THE PHOTORESIST COMPOSITION
A photoresist composition includes a novolac resin, a benzophenone photosensitizer and an ethylidyne tris phenol photosensitizer, and an organic solvent. Thus, a micropattern having a higher resolution than the resolution of an exposure apparatus is formed to decrease an amount of exposure and/or exposure time, thereby improving manufacturing reliability and productivity.
1 . A photoresist composition, comprising:
a novolac resin;
a benzophenone photosensitizer and an ethylidyne tris phenol photosensitizer in a weight ratio of the benzophenone photosensitizer to the ethylidyne tris phenol photosensitizer in a range from about 20:80 to about 80:20 based on a total weight of the benzophenone photosensitizer and the ethylidyne tris phenol photosensitizer; and
an organic solvent.
2 . The photoresist composition of claim 1 , wherein the benzophenone photosensitizer comprises a resultant of a benzophenone compound and a quinone diazide compound reaction.
3 . The photoresist composition of claim 1 , wherein the benzophenone photosensitizer comprises a resultant of 2,3,4,4′-tetrahydroxybenzophenone and a quinone diazide compound reaction.
4 . The photoresist composition of claim 1 , wherein the ethylidyne tris phenol photosensitizer comprises a resultant of an ethylidyne tris phenol compound and a quinone diazide compound reaction.
5 . The photoresist composition of claim 1 , wherein the ethylidyne tris phenol photosensitizer comprises a resultant of 4,4′,4″-ethylidyne tris phenol and a quinone diazide compound reaction.
6 . The photoresist composition of claim 1 , wherein the weight ratio of the benzophenone photosensitizer to the ethylidyne tris phenol photosensitizer is about 40:60.
7 . The photoresist composition of claim 1 , wherein the novolac resin comprises a phenol compound including an m-cresol and a p-cresol in a weight ratio of the m-cresol to the p-cresol in a range from about 40:60 to about 60:40.
8 . The photoresist composition of claim 1 , wherein the novolac resin comprises a phenol compound including an m-cresol and a p-cresol in a weight ratio of the m-cresol to the p-cresol of about 50:50.
9 . The photoresist composition of claim 1 , wherein the novolac resin has a weight average molecular weight in a range from about 3,000 to about 15,000.
10 . The photoresist composition of claim 1 , wherein a content of the novolac resin is in a range from about 5 percent by weight to about 20 percent by weight, a content of the photosensitizers is in a range from about 2 percent by weight to about 10 percent by weight, and a content of the organic solvent is in a range from about 75 percent by weight to about 90 percent by weight of the composition.
11 . A method of manufacturing a display substrate, the method comprising:
forming a switching element connected to a gate line and a data line;
forming a transparent electrode layer on a substrate having the switching element;
forming a photoresist pattern using a photoresist composition comprising: a) a novolac resin, b) a benzophenone photosensitizer and an ethylidyne tris phenol photosensitizer in a weight ratio of the benzophenone photosensitizer to the ethylidyne tris phenol photosensitizer in a range from about 20:80 to about 80:20 based on a total weight of the benzophenone photosensitizer and the ethylidyne tris phenol photosensitizer, and c) an organic solvent, the photoresist pattern formed on the transparent electrode layer; and
patterning the transparent electrode layer using the photoresist pattern as an etching mask to form a pixel electrode comprising a plurality of microelectrodes.
12 . The method of claim 11 , wherein each of the microelectrodes has a width in a range from about 2.0 μm to about 2.8 μm.
13 . The method of claim 11 , wherein a distance between the microelectrodes adjacent to each other is in a range from about 2.0 μm to about 2.8 μm.
14 . The method of claim 11 , further comprising preparing the benzophenone photosensitizer by reacting a benzophenone compound with a quinone diazide compound.
15 . The method of claim 11 , further comprising preparing the ethylidyne tris phenol photosensitizer by reacting an ethylidyne tris phenol compound with a quinone diazide compound.
16 . The method of claim 11 , further comprising forming the novolac resin using a phenol compound including an m-cresol and a p-cresol in a weight ratio of the m-cresol to the p-cresol in a range from about 40:60 to about 60:40.
17 . The method of claim 11 , wherein the novolac resin has a weight average molecular weight in a range from about 3,000 to about 15,000.
18 . The method of claim 11 , wherein a content of the novolac resin is in a range from about 5 percent by weight to about 20 percent by weight, a content of the photosensitizer is in a range from about 2 percent by weight to about 10 percent by weight, and a content of the organic solvent is in a range from about 75 percent by weight to about 90 percent by weight.