Progresses and Challenges of EUV Lithography Materials

Abstract

In the last years the continuous efforts on the development of EUV lithography has allowed to push the lithographic performances of the EUV photoresists on the ASML NXE:3100 full field exposure tool at imec. The latest chemically amplified photoresists can reach an ultimate resolution of 16 nm and 24 nm for line-space (L/S) and dense contacts (CH), respectively, but the major issue on EUV photoresists remains to simultaneously meet resolution, sensitivity, line-edge roughness (LER) for LS and local CD uniformity (LCDU) for CH, suggesting that the desired performance characteristics of EUV photoresists may require the development of new EUV materials. Aiming to this, imec has recently started a new project to look into novel materials for EUV lithography to explore alternative approaches that can offer superior characteristics in photoresist imaging: improved LER and line collapse, high sensitivity and high etch resistance. In this paper we report the first results from the exploration of new EUV alternative materials and the latest results from the conventional EUV photoresist evaluation and process optimization at imec towards the ASML NXE:3300 full field exposure tool.

Metal Sensitizer in Chemically Amplified EUV Resist: a Study of Sensitivity Enhancement and Dissolution

“…The drawback of metal oxide resist is relatively low sensitivity, while nanoparticle resists lack enough resolution. Although these metal containing resist utilize novel patterning mechanism and smaller building blocks, RLS tradeoff is still observed [11]. In addition, due to relative short history of the metal resist, integration of these novel metal resists into high volume manufacturing requires tedious efforts in resist optimization and risk management.…”

Synthesis of UV-curable polycarbonate diols (PCDL)-based polyurethane acrylate for negative photoresist

“…The differences in solubilities between the exposed and unexposed areas allow the production of predesigned patterns after development. The main requirements of photoresists are high photosensitivity, high resolution, high thermal stability, and good adhesion to the substrate [20]. Generally, photoresists consist of a matrix resin, a photoinitiator, solvent, and other additives [21].…”

Metal-containing Materials as Turning Point of EUV Lithography

“…It is in this frame that imec has started a new project [1] in 2014 to look into novel materials for EUV lithography and explore alternative approaches that potentially can offer benefits in terms of resolution and LWR, patterning image fidelity, line collapse and etch resistance.…”