In this work, we investigate strain effects induced by the deposition of gate dielectrics on the valence band structures in Si （110） nanowire via the simulation of strain distribution and the calculation of a genera...In this work, we investigate strain effects induced by the deposition of gate dielectrics on the valence band structures in Si （110） nanowire via the simulation of strain distribution and the calculation of a generalized 6 × 6k .p strained valence band. The nanowire is surrounded by the gate dielectric. Our simulation indicates that the strain of the amorphous SiO2 insulator is negligible without considering temperature factors. On the other hand, the thermal residual strain in a nanowire with amorphous SiO2 insulator which has negligible lattice misfit strain pushes the valence subbands upwards by chemical vapour deposition and downwards by thermal oxidation treatment. In contrast with the strain of the amorphous SiO2 insulator, the strain of the HfO2 gate insulator in Si （110） nanowire pushes the valence subbands upwards remarkably. The thermal residual strain by HfO2 insulator contributes to the up-shifting tendency. Our simulation results for valence band shifting and warping in Si nanowires can provide useful guidance for further nanowire device design.展开更多
This paper studies the elastic deformation field in lattice-mismatched Ge-Si core-shell nanowires(NWs).Infinite wires with a cylindrical cross section under the assumption of translational symmetry are considered.The ...This paper studies the elastic deformation field in lattice-mismatched Ge-Si core-shell nanowires(NWs).Infinite wires with a cylindrical cross section under the assumption of translational symmetry are considered.The strain distributions are found by minimizing the elastic energy per unit cell using finite element method.This paper finds that the trace of the strain is discontinuous with a simple,almost piecewise variation between core and shell,whereas the individual components of the strain can exhibit complex variations.The simulation results are prerequisite of strained band structure calculation,and pave a way for further investigation of strain effect on the related transport property simulation.展开更多
基金Project supported by the National Basic Research Program of China (Grant No. 2006CB302705)the Foundation for Key Program of Ministry of Education, China (Grant No. 107003)
文摘In this work, we investigate strain effects induced by the deposition of gate dielectrics on the valence band structures in Si （110） nanowire via the simulation of strain distribution and the calculation of a generalized 6 × 6k .p strained valence band. The nanowire is surrounded by the gate dielectric. Our simulation indicates that the strain of the amorphous SiO2 insulator is negligible without considering temperature factors. On the other hand, the thermal residual strain in a nanowire with amorphous SiO2 insulator which has negligible lattice misfit strain pushes the valence subbands upwards by chemical vapour deposition and downwards by thermal oxidation treatment. In contrast with the strain of the amorphous SiO2 insulator, the strain of the HfO2 gate insulator in Si （110） nanowire pushes the valence subbands upwards remarkably. The thermal residual strain by HfO2 insulator contributes to the up-shifting tendency. Our simulation results for valence band shifting and warping in Si nanowires can provide useful guidance for further nanowire device design.
文摘This paper studies the elastic deformation field in lattice-mismatched Ge-Si core-shell nanowires(NWs).Infinite wires with a cylindrical cross section under the assumption of translational symmetry are considered.The strain distributions are found by minimizing the elastic energy per unit cell using finite element method.This paper finds that the trace of the strain is discontinuous with a simple,almost piecewise variation between core and shell,whereas the individual components of the strain can exhibit complex variations.The simulation results are prerequisite of strained band structure calculation,and pave a way for further investigation of strain effect on the related transport property simulation.
