With the trends in miniaturization, and particularly the introduction of micro- and nano-electro-mechanical system, piezoelectric materials used in microelectronic devices are deposited usually in the form of thin fil...With the trends in miniaturization, and particularly the introduction of micro- and nano-electro-mechanical system, piezoelectric materials used in microelectronic devices are deposited usually in the form of thin film on elastic substrates. In this work, the bending of a bilayer comprising a piezoelectric film deposited on an elastic substrate, due to the mismatch, is investigated. An analytic formula relating the curvature of the bilayer to the mismatch, the electroelastic constants and the film thickness is obtained, and from this formula, a transverse piezoelectric constant d31 can be estimated. Meanwhile the influence of electrornechanical coupling coefficient on the curvature is discussed.展开更多
The reliability of a substrate curvature-based stress measurement method for CrN thin films on substrate with fluctuant surface was discussed.The stress error led by the ignorance of substrate thermal deformation was ...The reliability of a substrate curvature-based stress measurement method for CrN thin films on substrate with fluctuant surface was discussed.The stress error led by the ignorance of substrate thermal deformation was studied.Results showed that this error could be as large as several hundred MPa under general deposition conditions.Stress in the CrN thin films with different thicknesses ranging from 110 to 330 nm on stainless steel was studied by this method,in comparison with conventional results on silicon wafer.The thin films＇ morphology and structure were investigated and related to the film stress.A significant result of the comparison is that stress evolution in the thin films on steel obviously differs from that on silicon wafer,not only because the two substrates have different coefficients of thermal expansion,which provokes thermal stress,but also the considerable discrepancy in the thin films＇ grain coarsening rate and structure that induce different intrinsic stresses.展开更多
基金Project supported by the Zhejiang Provincial Natural Science Foundation,China(Grant No.Y6100440)
文摘With the trends in miniaturization, and particularly the introduction of micro- and nano-electro-mechanical system, piezoelectric materials used in microelectronic devices are deposited usually in the form of thin film on elastic substrates. In this work, the bending of a bilayer comprising a piezoelectric film deposited on an elastic substrate, due to the mismatch, is investigated. An analytic formula relating the curvature of the bilayer to the mismatch, the electroelastic constants and the film thickness is obtained, and from this formula, a transverse piezoelectric constant d31 can be estimated. Meanwhile the influence of electrornechanical coupling coefficient on the curvature is discussed.
基金the National Natural Science Foundation of China(11672285)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB22040502)+3 种基金China Postdoctoral Science Foundation(2018M642532)the Fundamental Research Funds for the Central Universities(WK2090050046)the Collaborative Innovation Center of Suzhou Nano Science and Technologythe Fundamental Research Funds for the Central Universities.
文摘The reliability of a substrate curvature-based stress measurement method for CrN thin films on substrate with fluctuant surface was discussed.The stress error led by the ignorance of substrate thermal deformation was studied.Results showed that this error could be as large as several hundred MPa under general deposition conditions.Stress in the CrN thin films with different thicknesses ranging from 110 to 330 nm on stainless steel was studied by this method,in comparison with conventional results on silicon wafer.The thin films＇ morphology and structure were investigated and related to the film stress.A significant result of the comparison is that stress evolution in the thin films on steel obviously differs from that on silicon wafer,not only because the two substrates have different coefficients of thermal expansion,which provokes thermal stress,but also the considerable discrepancy in the thin films＇ grain coarsening rate and structure that induce different intrinsic stresses.
