Achieving historically anticipated improvement in the performance of integrated circuits is challenging,due to the increasing cost and complexity of the required technologies with each new generation.To overcome this ...Achieving historically anticipated improvement in the performance of integrated circuits is challenging,due to the increasing cost and complexity of the required technologies with each new generation.To overcome this limitation,the exploration and development of novel interconnect materials and processes are highly desirable in the microelectronics field.Molybdenum(Mo)is attracting attention as an advanced interconnect material due to its small resistivity size effect and high cohesive energy;however,effective processing methods for such materials have not been widely investigated.Here,we investigate the electrochemical behavior of ions in the confined nanopores that affect the electrical properties and microstructures of nanoscale Mo and Mo-Co alloys prepared via template-assisted electrodeposition.Additives in an electrolyte allow the deposition of extremely pure metal materials,due to their interac-tion with metal ions and nanopores.In this study,boric acid and tetrabutylammonium bisulfate(TBA)were added to an acetate bath to inhibit the hydrogen evolution reaction.TBA accelerated the reduction of Mo at the surface by inducing surface conduction on the nanopores.Metallic Mo nanowires with a 130 nm diameter synthesized through high-aspect-ratio nanopore engineering exhibited a resistivity of(63.0±17.9)μΩcm.We also evaluated the resistivities of Mo-Co alloy nanowires at various compo-sitions toward replacing irreducible conventional barrier/liner layers.An intermetallic compound formed at a Mo composition of 28.6 at%,the resistivity of the Mo-Co nanowire was(58.0±10.6)μΩcm,indicat-ing its superior electrical and adhesive properties in comparison with those of conventional barriers such as TaN and TiN.Furthermore,density functional theory and non-equilibrium Green's function calcula-tions confirmed that the vertical resistance of the via structure constructed from Mo-based materials was 21%lower than that of a conventional Cu/Ta/TaN structure.展开更多
Monodisperse Au nanoparticles(NPs)have been synthesized at room temperature via a burst nucleation of Au upon injection of the reducing agent t-butylamine-borane complex into a 1,2,3,4-tetrahydronaphthalene solution o...Monodisperse Au nanoparticles(NPs)have been synthesized at room temperature via a burst nucleation of Au upon injection of the reducing agent t-butylamine-borane complex into a 1,2,3,4-tetrahydronaphthalene solution of HAuCl4·3H2O in the presence of oleylamine.The as-synthesized Au NPs show size-dependent surface plasmonic properties between 520 and 530 nm.They adopt an icosahedral shape and are polycrystalline with multiple-twinned structures.When deposited on a graphitized porous carbon support,the NPs are highly active for CO oxidation,showing 100%CO conversion at-45°C.展开更多
Memristive heterostructures,composed of reduced graphene oxide with different degree of reduction,were demonstrated through a simple method of‘direct electron-beam writing’on graphene oxide.Irradiation with an elect...Memristive heterostructures,composed of reduced graphene oxide with different degree of reduction,were demonstrated through a simple method of‘direct electron-beam writing’on graphene oxide.Irradiation with an electron beam at various doses and accelerating voltages made it possible to define highand low-conductivity graphene-oxide areas.The electron beam-reduced graphene oxide/graphene oxide heterostructure clearly exhibited a nonlinear behavior and a well-controlled resistive switching characteristic at a low operating-voltage range(<1 V).The proposed memristive heterostructures are promising for highly-efficient digital storage and information process as well as for analogous neuromorphic computations.展开更多
基金supported by the Basic Science Research Program of the National Research Foundation of Koreafunded by the Ministry of Education of the Republic of Korea(2021R1A6A3A13046504)+1 种基金the Ministry of Science and ICT of the Republic of Korea(2022M3H4A1A04096339 and 2020M3F3A2A01081585)the Samsung Electronics Co.,Ltd.(IO210317-08500-01).
文摘Achieving historically anticipated improvement in the performance of integrated circuits is challenging,due to the increasing cost and complexity of the required technologies with each new generation.To overcome this limitation,the exploration and development of novel interconnect materials and processes are highly desirable in the microelectronics field.Molybdenum(Mo)is attracting attention as an advanced interconnect material due to its small resistivity size effect and high cohesive energy;however,effective processing methods for such materials have not been widely investigated.Here,we investigate the electrochemical behavior of ions in the confined nanopores that affect the electrical properties and microstructures of nanoscale Mo and Mo-Co alloys prepared via template-assisted electrodeposition.Additives in an electrolyte allow the deposition of extremely pure metal materials,due to their interac-tion with metal ions and nanopores.In this study,boric acid and tetrabutylammonium bisulfate(TBA)were added to an acetate bath to inhibit the hydrogen evolution reaction.TBA accelerated the reduction of Mo at the surface by inducing surface conduction on the nanopores.Metallic Mo nanowires with a 130 nm diameter synthesized through high-aspect-ratio nanopore engineering exhibited a resistivity of(63.0±17.9)μΩcm.We also evaluated the resistivities of Mo-Co alloy nanowires at various compo-sitions toward replacing irreducible conventional barrier/liner layers.An intermetallic compound formed at a Mo composition of 28.6 at%,the resistivity of the Mo-Co nanowire was(58.0±10.6)μΩcm,indicat-ing its superior electrical and adhesive properties in comparison with those of conventional barriers such as TaN and TiN.Furthermore,density functional theory and non-equilibrium Green's function calcula-tions confirmed that the vertical resistance of the via structure constructed from Mo-based materials was 21%lower than that of a conventional Cu/Ta/TaN structure.
基金by NSF/DMR 0606264 and a GAANN fellowship(Y.Lee).
文摘Monodisperse Au nanoparticles(NPs)have been synthesized at room temperature via a burst nucleation of Au upon injection of the reducing agent t-butylamine-borane complex into a 1,2,3,4-tetrahydronaphthalene solution of HAuCl4·3H2O in the presence of oleylamine.The as-synthesized Au NPs show size-dependent surface plasmonic properties between 520 and 530 nm.They adopt an icosahedral shape and are polycrystalline with multiple-twinned structures.When deposited on a graphitized porous carbon support,the NPs are highly active for CO oxidation,showing 100%CO conversion at-45°C.
基金supported financially by the Russian Foundation of Basic Research(Nos.19-29-03050 and 18-29-19120)the National Research Foundation of Korea(Nos.2016R1A6A1A03012877,2017R1D1A1B03035102 and 2017R1A2B4004281).
文摘Memristive heterostructures,composed of reduced graphene oxide with different degree of reduction,were demonstrated through a simple method of‘direct electron-beam writing’on graphene oxide.Irradiation with an electron beam at various doses and accelerating voltages made it possible to define highand low-conductivity graphene-oxide areas.The electron beam-reduced graphene oxide/graphene oxide heterostructure clearly exhibited a nonlinear behavior and a well-controlled resistive switching characteristic at a low operating-voltage range(<1 V).The proposed memristive heterostructures are promising for highly-efficient digital storage and information process as well as for analogous neuromorphic computations.
