Development of metal-organic cluster based negative tone resist: pre-screened through the helium-ion beam prelude to extreme ultraviolet lithography (EUVL) applications

Ultrasensitive metal-organic cluster resist for patterning of single exposure high numerical aperture extreme ultraviolet lithography applications

“…The reaction was carried out at 70°C for 24 hrs, after which the final product was washed with toluene and dried at 50°C in an oven for 12 hrs. After that, the ready-to-use dry powder form of In-MAA MOC resist was kept in a vacuum desiccator to prevent it from atmospheric moisture 46 . A single crystal structure of the In-MAA MOC (InC14normalO8normalH18) generated from the non-destructive single-crystal x-ray diffraction analysis is shown in Fig.…”

“…After that, the ready-to-use dry powder form of In-MAA MOC resist was kept in a vacuum desiccator to prevent it from atmospheric moisture. 46 A single crystal structure of the In-MAA MOC (InC 14 O 8 H 18 ) generated from the non-destructive single-crystal x-ray diffraction analysis is shown in Fig. 1(a).…”

“…Due to its considerably small molecular nature, they can attain the desired parameters for EUV photon absorption, ultra-sensitivity, high etch resistance, and RLS trade-off while offering intrinsically small and homogenous monodisperse, size distribution by selecting the appropriate metal entities of higher EUV absorption coefficient and weaker binding ligands. In pursuance of this, our group has been extensively involved in the design and development of high-performance EUV resists development 20 , 22 , 46 …”

“…[42][43][44][45] To this end, several inorganic-containing hybrids resist strategies are being actively investigated for EUVL applications, largely unpopular due to the higher dose, necessary to generate solubility contrast of HR resist patterns. Metal-organic clusters (MOCs) are hybrid resist materials 20,22,42,43,46 with significant potential for NA ∼ 0.5, EUVL resist platforms. Due to its considerably small molecular nature, they can attain the desired parameters for EUV photon absorption, ultra-sensitivity, high etch resistance, and RLS trade-off while offering intrinsically small and homogenous monodisperse, size distribution by selecting the appropriate metal entities of higher EUV absorption coefficient and weaker binding ligands.…”

“…In pursuance of this, our group has been extensively involved in the design and development of high-performance EUV resists development. 20,22,46 In this work, we have developed an ultrasensitive negative tone indium-methacrylic acid (In-MAA)-based MOCs resist amenable toward h-NA ∼ 0.5, EUVL applications, comprising of an indium metal core surrounded with the weakly bonded organic moiety MAA, to offer an effective solubility switching due to the cross-linking of these double bonds at the EUV photon exposure or charged particles/ions irradiations at a lower dose. A key novelty in resist is the inherent controllability of various resist parameters and ultra-sensitivity of ∼2.3 mJ∕cm 2 towards h-NA EUV exposure (which has been ascertained at the microfield exposure tool (MET) tool at Lawrence Berkeley National Laboratory (LBNL), United States), high contrast (γ), etch resistance and pattern transfer.…”