| 摘要 |
PURPOSE:To obtain the titled resin having remarkably improved resolution and improved film retentivity by using a specific weight ratio of metha-/para- cresols as a cresol isomer mixture, and by specifying a weight average molecular weight of 2,000-15,000 in the novolak resin. CONSTITUTION:The novolak resin is produced by reacting the cresol isomer mixture with formaldehyde in the presence of an acid. The weight ratio (metha/ para) of metha and para cresols in the cresol isomer mixture is (45/55)-(20/80). By using the novolak resin having the weight average molecular weight of 2,000-15,000, preferably 2,500-9,000, for the positive type photoresist, the gammavalue which is important fundamental performance of the resist is largely improved. The preparation of the positive type photoresist solution is carried out by dissolving a quinone diazide compd. and the novolak resin in a solvent respectively and mixing them. The ratio of the novolak resin and the quinone diazide compd. is preferably (1:1)-(1:6). |
