Dependence of the quality of thick resist structures on resist baking

Interest in thick photoresist applications is steadily growing. Specialised equipment has been developed to cope with the new challenges to process and pattern extremely thick photoresist layers. A decisive step in the preparation of resist layers is the pre-baking. The impact of three different pre-baking technologies on the resist performance has been investigated. Resist patterns obtained after oven, hotplate or IR pre-baking exhibit equally high quality. Compared to oven and hotplate baking, the process length and energy consumption is markedly reduced using IR radiation, favouring this variant to be the optimum pre-baking process for very thick photoresist layers.