Focusing on nanoparticles based photomultiplier in n-CARs

摘要

To meet the International Roadmap for Device and Systems (IRDS), the development of an advanced lithography process for next-generation (NG) technology node is a vital and challenging task, as we are reaching to its physical limits. In the progress of high volume manufacturing (HVM) at sub-12 nm node, it is very important that resist materials should possess low line edge roughness (LER) and high sensitivity (E_0) using extreme ultraviolet (EUV) and its analogous exposure systems. Apart from standard chemically amplified resist (CAR), acid-free non-CAR has been studied immensely as a potential candidate for NG patterning. To achieve sub-12 nm patterns, a complete study for newly developed n-CAR is required to make sure that developed resist formulation is performing optimally. Aside from the n-CARs, we adopted a novel patterning approach using He~+ ion beam lithography with less proximity effect. Here we present the metallic nanoparticle photo-multiplier (high optical density materials for λ ~13.5 nm) embedded with n-CAR for better photo-absorption and high-resolution pattern development. The silver (Ag- OD 12 w.r.t Carbon) nanoparticles (NPs) with ~2 nm regime were embedded into MAPDST homo-polymer ((4-(methacryloyloxy)phenyl) dimethylsulfonium trifluoromethanesulfonate). To investigate the high-resolution patterning synthesized photoresist was exposed to e-beam (E_e) and Helium ion (E_(He)) beam lithography. The patterned samples were developed in aqueous solution and revealed the negative tone with the sensitivity of 172 μC/cm~2 and 50.4 μC/cm~2 for E_e and E_(He) respectively. The MAPDST-Ag resist found stable for more than 1 year, which clearly suggests that there is no sign of Ag-NPs agglomeration in the formulation. Thence, evidently, prove the considerable shelf life of developed resist formulation and can be used in NG semiconductor device HVM and other electronic device applications.