During hybrid lithography of thermal nanoimprint with optical lithography, where both steps are performed within one single resist layer, changes of the lithographic performance of the material used during the first step, the thermal imprint, are essential for the overall lithography result. In order to characterize such changes two positive tone photoresists, AZ-1505 and ARP- 3510, were characterized by measurement of dose curves (relative resist layer thickness remaining after exposure and development) after a specific temperature treatment simulating the thermal imprint step. Obviously the two materials are affected in a somewhat different way. After temperature treatment at 120°C, ARP-3510 still features a higher sensitivity than AZ-1505, but the latter shows a higher contrast.© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.