Novolak resins and the microelectronic revolution

Stanley F. Wanat, Robert R. Plass, and M. Dalil Rahman AZ Electronic Materials USA Corporation, Branchburg, New Jersey 08876 Novolak resins have had a significant impact on modern life, in general, and more specifically, on photolithography and the microelectronic market in particular. Since their commercialization around 1910, they have found a wide variety of uses. With the switch from solvent developable negative photoresists to the base soluble novolak/diazonaphthoquinone systems, the growth of the resist market has skyrocketed. Successive generations of higher quality resists required refinements in the synthesis, fractionation and purification of the novolak resins used in making those resists. The use of stabilization techniques and continuous processing methods for the preparation of novolak resins and the resists made with them are discussed.