abstract |
(57) [Abstract] [Problem] Finely forming dense and isolated patterns, Provided are a phenol novolac resin and a positive photoresist composition which are excellent in sensitivity, resolution and depth of focus characteristics. SOLUTION: O-o/op by 13 C-NMR measurement /Pp peak intensity ratio is 5.0-8.5/2.5- A phenol novolac resin having a Mw of 3,000 to 20,000, which is 4.5/1 and has a phenolic structural unit represented by the following formula. [Chemical 1] |