0. positive photoresist
Like e.g. AR-P 3100, 3200, 3500, 3700 are composed of a combination of film forming agents like e.g. cresol novolac resins and light-sensitive components such as e.g. naphthoquinone diazide, which are for example dissolved in solvents like methoxypropyl acetate (equivalent to PGMEA). The addition of the light-sensitive component to the alkali-soluble novolac results in a reduced alkaline solubility. After exposure to UV light (308 - 450 nm) using an exposure mask, the light-sensitive component is converted in exposed areas into the corresponding indene carboxylic acid derivative which then increases the alkaline solubility of positive resists by a factor of about 100. The refractive index of novolac-based resists is in a range of 1.60. After development, only areas protected by the mask remain while the exposed areas are dissolved. Photoresists provide an excellent protection against etch media with pH- values between 0 and 13.
正型光阻: 編號AR_P 3100, AR-P 3200, AR-P 3500, AR-P 3700等系列. 組成份主要是酚醛樹酯(Novolac), NQD疊氮型感光劑, 及溶劑(例PGMEA). NQD感光劑會降低Novolac樹酯在鹼性溶劑中的溶解力, 但是在紫外線(波長 308 – 450 nm)照射下會轉化成茚羧酸(ICA)衍生物, 使Novolac樹酯在鹼性液的溶解力提高了100倍. 此類型光阻的折射率大約是1.6. 因此曝光顯影後, 未照射區域(被光照保護)會留存, 相對的照射區(被曝光區域)則溶解於顯影液.