Silicon nitride/cobalt tungsten boride (SiN/CoWB) passivation layer improves mass transport rate at copper thin film layers of semiconductor wafers after chemical mechanical polishing process. This study evaluates mass transport at the interface between copper and passivation layers by stress relaxation method, followed by deduction of interface diffusivity via a kinetic model. For comparison, SiN/CoWB, SiN, silicon carbon nitride (SiCN) and silicon carbide (SiC) passivation layers are introduced. A thin layer of SiN/CoWB demonstrates an outstanding performance as diffusion retarding material, especially at high temperature. The order of stress relaxation in terms of passivation layers is SiN/CoWB < SiN < SiCN < SiC, implying the order of mass transport at the interface. Using the kinetic model, the diffusivities and activation energies regarding passivation layers are calculated and reveal a good agreement with experimental results.
Polyacrylamide (PAM) was used for matrix material to fabricate composite hydrogels reinforced with natural cellulose nanocrystal (CNC). Invoking in situ free-radical polymerization with different concentration of cellulose nanocrystal, polyacrylamide hydrogels were fabricated. The chemical structure, compression strength, morphology and dielectric properties of the composite hydrogels were investigated. The CNC played a role as a reinforcing filler and a multifunctional cross-linker in the hydrogel. The elastic modulus and dielectric property of the composite hydrogels increased as increasing the CNC concentration. The electrical actuation test of the PAM/CNC hydrogel shows its possibility for soft electro-active materials for active lens.
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Design and fabrication strategies of cellulose nanocrystal-based hydrogel and its highlighted application using 3D printing: A review Xiao He, Qingye Lu Carbohydrate Polymers.2023; 301: 120351. CrossRef
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