Research objectives and content The goal of this project is the development of a new positive tone resist for deep X- ray lithography (DXRL) with high sensitivity. The standard resist material for deep X- ray lithography is poly(methyl methacrylate) (PMMA) which is very suitable, since structures with a high resolution can be obtained. A disadvantage, however, is the low sensitivity of PMMA which demands long irradiation times and leads, therefore, to a relatively expensive process. In order to obtain a resist with high sensitivity, the principle of chemical amplification should be used. This concept has been described for photolithography by Ito and Willson, applied for X-ray lithography by Dammel, and used in the field of DXRL by Schenk for the development of a negative tone resist. In this proposal two concepts for the development of positive tone resist systems for DXRL are described in detail. These resist systems containing two or three components, a polymer matrix, an acid generator, and in one case an additional crosslinker. Upon irradiation the acid generator is releasing a proton which leads to a series of chemical reactions resulting in a increased solubiltiy of the irradiated regions. For both concepts it is absolutely necessary that the different resist components have to be optimized for the DXRL process. Training content (objective, benefit and impact) The postdoctoral work includes the tasks synthesis and characterization of polymers and further resist components and investigation of the acid catalyzed cleavage of the new polymers and polymer networks. Furthermore, the resist films have to be prepared, irradiated and the resulting microstructures have to be analyzed. A successful work in the field of DXRL needs the application of different techniques and equipment (e. g. DSC, rheometry, phase analysis by light microscopy, SEM, AFM,FT-IR,UV-vis). Links with industry / industrial relevance (22) For the DXRL process IMM is manufacturing substrates which are coated with thick resist layers. A spin-off company of IMM should overtake this sphere of activity in the future.