| 摘要 |
PROBLEM TO BE SOLVED: To provide: a novolac-type phenolic resin which enables the provision of a practically useful photoresist composition having a good balance among high heat resistance, high sensitivity, a high residual film ratio, a high resolution and etching resistance; and a photoresist composition containing the novolac-type phenolic resin.SOLUTION: A novolac-type phenolic resin is obtained by the polycondensation reaction of a phenol component (a) with an aldehyde component (b). The phenol component (a) includes an alkyl phenol (a1) containing m-cresol and p-cresol as essential components and a phenol (a2), and the aldehyde component (b) includes an aliphatic polyaldehyde (b1) and formaldehyde (b2). The weight average molecular weight of the novolac-type phenolic resin is 4,000 or more. |
