To stabilize the resist profile for subsequent process steps like wet etching or high energy implantation in our 200mm fabrication the so-called UV harden process is used. This UV harden process step, mainly used for MUV resist materials, leads to further cross-linking and curing of the resist material. The aim is to remove most of the solvents still contained in the resist patterns and to destroy the remaining light-sensitive components (photoactive compounds) in order to stabilize the resist profile. At the same time, the adhesion of critical structures to the surface should be improved to provide a better foundation for subsequent patterning or implant processes.

Unfortunately, for the process transfer of our CMOS technologies from 200mm to 300mm fabrication the UV harden process cannot be used due to missing tool availability on the market. Therefore, it is necessary to find an alternative process which is able to substitute the UV harden process with comparable defectivity behavior.

In this paper we will show our evaluations for a detailed understanding of the UV harden process for different DUV and MUV resist materials and process variations. We will present our characterization methods to judge on resist material parameters like etch rate, adhesion or film stress. Additionally, the currently used regular defect density test for our UV harden equipment and processes will be presented.