Degradation of a metallic film under harsh thermal-mechanical-electrical coupling field conditions determines its service temperature and lifetime.In this work,the self-heating degradation behaviors of Pt thin films a...Degradation of a metallic film under harsh thermal-mechanical-electrical coupling field conditions determines its service temperature and lifetime.In this work,the self-heating degradation behaviors of Pt thin films above 1000℃were studied in situ by TEM at the nanoscale.The Pt films degraded mainly through void nucleation and growth on the Pt-SiN_(x)interface.Voids preferentially formed at the grain boundary and triple junction intersections with the interface.At temperatures above 1040℃,the voids nucleated at both the grain boundaries and inside the Pt grains.A stress simulation of the suspended membrane suggests the existence of local tensile stress in the Pt film,which promotes the nucleation of voids at the Pt-Si Nxinterface.The grain-boundary-dominated mass transportation renders the voids grow preferentially at GBs and triple junctions in a Pt film.Additionally,under the influence of an applied current,the voids that nucleated inside Pt grains grew to a large size and accelerated the degradation of the Pt film.展开更多
基金financially supported by the Basic Science Center Program for Multiphase Evolution in Hyper-gravity of the National Natural Science Foundation of China(51988101)NSFC Programs(Nos.52071003,91860202,11604006)+3 种基金the Beijing Municipal Education Commission Project(Nos.PXM2020014204000021 and PXM201901420400032)the Beijing Outstanding Young Scientists Projects(No.BJJWZYJH01201910005018)the Beijing Natural Science Foundation(No.Z180014)the“111 Project(No.DB18015)。
文摘Degradation of a metallic film under harsh thermal-mechanical-electrical coupling field conditions determines its service temperature and lifetime.In this work,the self-heating degradation behaviors of Pt thin films above 1000℃were studied in situ by TEM at the nanoscale.The Pt films degraded mainly through void nucleation and growth on the Pt-SiN_(x)interface.Voids preferentially formed at the grain boundary and triple junction intersections with the interface.At temperatures above 1040℃,the voids nucleated at both the grain boundaries and inside the Pt grains.A stress simulation of the suspended membrane suggests the existence of local tensile stress in the Pt film,which promotes the nucleation of voids at the Pt-Si Nxinterface.The grain-boundary-dominated mass transportation renders the voids grow preferentially at GBs and triple junctions in a Pt film.Additionally,under the influence of an applied current,the voids that nucleated inside Pt grains grew to a large size and accelerated the degradation of the Pt film.
