Photoresist for enhanced patterning performance
A photoresist is composed of an alkali soluble resin, a photosensitive agent and a solvent. The alkali soluble resin includes a first type novolak resin synthesized from meta-cresol, and the first novolak resin has an average molecular weight of about 8000 to 25000 and a polydispersity index of four or less. The content of the first type novolak resin in the alkali soluble resin is about 5 to 30 wt. %. The photoresist can further include a second type novolak resin synthesized from a mixture of meta-cresol and para-cresol. The second novolak resin has an average molecular weight of about 2000 to 6000, and the weight ratio of meta-cresol to para-cresol is 4:6. The content of the second type novolak resin in the alkali soluble resin is about 70 to 95 wt. %.
1 . A photoresist comprising an alkali soluble resin, a photosensitive agent and a solvent, wherein the alkali soluble resin comprises a first type novolak resin synthesized from meta-cresol, the first novolak resin having an average molecular weight of about 8000 to 25000.
2 . The photoresist of claim 1 , wherein the first novolak resin has a polydispersity index of less than or equal to 4.
3 . The photoresist of claim 1 , wherein the content of the first type novolak resin in the alkali soluble resin is about 5 to 30 wt. %.
4 . The photoresist of claim 1 , further comprising a second type novolak resin synthesized from meta-cresol and para-cresol, the second novolak resin having an average molecular weight of about 2000 to 6000, wherein the weight ratio of meta-cresol to para-cresol is 4:6.
5 . The photoresist of claim 4 , wherein the content of the second type novolak resin in the alkali soluble resin is about 70 to 95 wt. %.
6 . The photoresist of claim 1 , wherein the photosensitive agent comprises a diazide based compound.
7 . The photoresist of claim 6 , wherein the photosensitive agent comprises 2,3,4,4′-tetrahydroxy benzophenone-1,2-naphthoquinone diazide-5-sulfonate.
8 . The photoresist of claim 1 , wherein the content of the alkali soluble resin in the photoresist is about 5 to 45 wt. %.
9 . The photoresist of claim 1 , wherein the content of the photoresistive agent in the photoresist is about 1 to 20 wt. %.