Abstract
Cresol formaldehyde novolac resins (Cre/Form) having hard properties cannot be applied minutely the positivetype photoresist material onto dry fi lms. Therefore, a new development was needed, so we carried out the synthesis and application of cresol novolac resins having fl exibility. The polycondensation reactions of cresols (Cre) with adipaldehyde (Adp) were carried to obtain cresol adipaldehyde novolac resins (Cre/Adp). Cre/Adp having both a dissolving rate for alkaline aq. solution below 1000Å/sec and Mw over 3000 were chosen for the test. The 5μm thick cast fi lms of Cre/Adp were applied onto polyimide fi lms in order to evaluate the fl exibility properties of the obtained resins by observation of their bent parts. Though the Cre/Form resin of the bent part was scattered, the Cre/Adp resin was settled with just cracks. The fl exibility of the Cre/Adp resin was also confi rmed from the results of the dynamic storage modulus measurement, too. The lithography performance of the Cre/Adp resin coated 1.5μm in thickness onto the silicon wafers was examined. The residual membrane thickness was high (96%) and the resolution of the resist was up to 2.5μm.
