Ultrathin ZrBxOy films as diffusion barriers in Cu interconnects

Enhanced Ti0.84Ta0.16N diffusion barriers, grown by a hybrid sputtering technique with no substrate heating, between Si(001) wafers and Cu overlayers

“…After annealing the Cu/TiN bilayer at 700 °C, additional diffraction peaks appear at 2θ = 28.0, 35.2, 42.4, 44.6, 45.0, 58.0, and 65.2° arising from the appearance of the orthorhombic η ″-Cu 3 Si phase 26 . This compound is often reported as a reaction product due to Cu and Si interdiffusion through barrier layers in Cu/barrier/Si(001) stacks 27 , and therefore serves as a qualitative benchmark in evaluating barrier performance 1 , 3 , 4 , 27 . Formation of Cu 3 Si occurs locally at the barrier/Si interface 1 , 28 , 29 , and the 150% volume expansion 30 compared to Si results in the formation of hillocks as observed in Fig.…”

“…Diffusion barriers are vital components in integrated circuits (ICs), designed to impede interdiffusion between Cu metallization and doped Si layers 1 , 2 . Barrier failure leading to in-diffusion of Cu results in the formation of Cu silicides, which severely impair device performance and lifetime 1 , 3 , 4 . Since diffusion is a thermally-activated process, efficient diffusion barrier layers require a thermally-stable microstructure, with an electrical conductivity similar to that of Cu (1.74 µΩ-cm for bulk Cu, 2.0 µΩ-cm for a 1.5-µm-thick polycrystalline Cu film) 5 , 6 in order to optimize device functionality 7 .…”

Light and force dual-responsive waterborne polyurethane in multiple states

“…Mechanically responsive polymers [1][2][3][4][5] have attracted researchers' interests in the past decades, due to their potential application in mechanochromic force sensors, 6,7 mechanically induced catalysis, 8 self-reinforcing materials 9 and scaffolds for small molecule release. 10,11 Spiropyran (SP) is one of the most famous mechanophores due to its sensitive color generation when exposed in light [12][13][14][15] or applied stress, and the colorless SP experiences a ring-open process and transfers to the colored merocyanine (MC) (Scheme 1).…”

Mixed-phase Ni–Al as barrier layer against perovskite oxides to react with Cu for ferroelectric memory with Cu metallization

“…Perovskite electrodes being similar to PZT in structure, like La 0.5 Sr 0.5 CoO 3 (LSCO), SrRuO 3 (SRO) and LaNiO 3 (LNO), can provide a famous reliability of ferroelectric thin films [8,9]. On the other hand, with the shrink of the feature sizes in ultralarge scale integration microelectronic devices, Cu has been a viable dominant material for backend interconnects in Si semiconductor processing due to its superior electrical resistivity and resistance to electromigration [10][11][12]. The development of the next high density FeRAMs will provoke a motivation to integrate ferroelectric capacitors with Cu metallization in order to take advantage of their own strengths and complete the multiplication together.…”

“…A feasible solution to solve some above-mentioned issues in integrating ferroelectric capacitors with Cu metallization is two barrier schemes, i. e. oxygen diffusion barrier layer between Cu and perovskite oxide films, and diffusion barrier layer between Cu and Si or SiO 2 . In fact, a host of research works about the latter have been published with good physical properties unless the thermal stability greater than 800 o C or ultrathin thickness less than 5 nm [11,12]. This work is relatively easy to benefit from inexistence of oxygen environment and complex layer structure.…”