A band edge model in （101）-biaxial strained Si on relaxed Si1-x Gex alloy,or monoclinic Si （m-Si）,is presented using the k · p perturbation method coupled with deformation potential theory. Results show that ...A band edge model in （101）-biaxial strained Si on relaxed Si1-x Gex alloy,or monoclinic Si （m-Si）,is presented using the k · p perturbation method coupled with deformation potential theory. Results show that the [001], [001], [100], [100] valleys constitute the conduction band （CB） edge,which moves up in electron energy as the Ge fraction （x） increases. Furthermore,the CB splitting energy is in direct proportion to x and all the valence band （VB） edges move up in electron energy as x increases. In addition, the decrease in the indirect bandgap and the increase in the VB edge splitting energy as x increases are found. The quantitative data from the models supply valuable references for the design of the devices.展开更多
The feature of conduction band （CB） of Tensile-Strained Si（TS-Si） on a relaxed Si1-xGex substrate is systematically investigated, including the number of equivalent CB edge energy extrema, CB energy minima, the po...The feature of conduction band （CB） of Tensile-Strained Si（TS-Si） on a relaxed Si1-xGex substrate is systematically investigated, including the number of equivalent CB edge energy extrema, CB energy minima, the position of the extremal point, and effective mass. Based on an analysis of symmetry under strain, the number of equivalent CB edge energy extrema is presented; Using the K.P method with the help of perturbation theory, dispersion relation near minima of CB bottom energy, derived from the linear deformation potential theory, is determined, from which the parameters, namely, the position of the extremal point, and the longitudinal and transverse masses （m1^＊ and mt^＊）are obtained.展开更多
In this paper,the dispersion relationship is derived by using the k·p method with the help of the perturbation theory,and we obtain the analytical expression in connection with the deformation potential.The calcu...In this paper,the dispersion relationship is derived by using the k·p method with the help of the perturbation theory,and we obtain the analytical expression in connection with the deformation potential.The calculation of the valence band of the biaxial strained Ge/（001）Si1-xGex is then performed.The results show that the first valence band edge moves up as Ge fraction x decreases,while the second valence band edge moves down.The band structures in the strained Ge/（001）Si 0.4 Ge 0.6 exhibit significant changes with x decreasing in the relaxed Ge along the [0,0,k] and the [k,0,0] directions.Furthermore,we employ a pseudo-potential total energy package（CASTEP） approach to calculate the band structure with the Ge fraction ranging from x = 0.6 to 1.Our analytical results of the splitting energy accord with the CASTEP-extracted results.The quantitative results obtained in this work can provide some theoretical references to the understanding of the strained Ge materials and the conduction channel design related to stress and orientation in the strained Ge pMOSFET.展开更多
Calculations were performed on the band edge levels of （111）-biaxially strained Si on relaxed Si1-xGex alloy using the k.p perturbation method coupled with deformation potential theory. The results show that the con...Calculations were performed on the band edge levels of （111）-biaxially strained Si on relaxed Si1-xGex alloy using the k.p perturbation method coupled with deformation potential theory. The results show that the conduction band （CB） edge is characterized by six identicalvalleys, that the valence band （VB） edge degeneracies are partially lifted, and that both the CB and VB edge levels move up in electron energy as the Ge fraction （x） increases. In addition, the dependence of the indirect bandgap and the VB edge splitting energy on x was obtained. Quantitative data from the results supply valuable references for Si-based strained device design.展开更多
基金the National Ministries and Commissions of China(Nos.51308040203,9140A08060407DZ0103)~~
文摘A band edge model in （101）-biaxial strained Si on relaxed Si1-x Gex alloy,or monoclinic Si （m-Si）,is presented using the k · p perturbation method coupled with deformation potential theory. Results show that the [001], [001], [100], [100] valleys constitute the conduction band （CB） edge,which moves up in electron energy as the Ge fraction （x） increases. Furthermore,the CB splitting energy is in direct proportion to x and all the valence band （VB） edges move up in electron energy as x increases. In addition, the decrease in the indirect bandgap and the increase in the VB edge splitting energy as x increases are found. The quantitative data from the models supply valuable references for the design of the devices.
文摘The feature of conduction band （CB） of Tensile-Strained Si（TS-Si） on a relaxed Si1-xGex substrate is systematically investigated, including the number of equivalent CB edge energy extrema, CB energy minima, the position of the extremal point, and effective mass. Based on an analysis of symmetry under strain, the number of equivalent CB edge energy extrema is presented; Using the K.P method with the help of perturbation theory, dispersion relation near minima of CB bottom energy, derived from the linear deformation potential theory, is determined, from which the parameters, namely, the position of the extremal point, and the longitudinal and transverse masses （m1^＊ and mt^＊）are obtained.
基金Project supported by the Fundamental Research Funds for the Central Universities,China (Grant Nos. 72105499 and 72104089)the Natural Science Basic Research Plan in Shaanxi Province,China (Grant No. 2010JQ8008)
文摘In this paper,the dispersion relationship is derived by using the k·p method with the help of the perturbation theory,and we obtain the analytical expression in connection with the deformation potential.The calculation of the valence band of the biaxial strained Ge/（001）Si1-xGex is then performed.The results show that the first valence band edge moves up as Ge fraction x decreases,while the second valence band edge moves down.The band structures in the strained Ge/（001）Si 0.4 Ge 0.6 exhibit significant changes with x decreasing in the relaxed Ge along the [0,0,k] and the [k,0,0] directions.Furthermore,we employ a pseudo-potential total energy package（CASTEP） approach to calculate the band structure with the Ge fraction ranging from x = 0.6 to 1.Our analytical results of the splitting energy accord with the CASTEP-extracted results.The quantitative results obtained in this work can provide some theoretical references to the understanding of the strained Ge materials and the conduction channel design related to stress and orientation in the strained Ge pMOSFET.
基金supported by the Foundation from the National Ministries and Commissions(Nos.51308040203,6139801).
文摘Calculations were performed on the band edge levels of （111）-biaxially strained Si on relaxed Si1-xGex alloy using the k.p perturbation method coupled with deformation potential theory. The results show that the conduction band （CB） edge is characterized by six identicalvalleys, that the valence band （VB） edge degeneracies are partially lifted, and that both the CB and VB edge levels move up in electron energy as the Ge fraction （x） increases. In addition, the dependence of the indirect bandgap and the VB edge splitting energy on x was obtained. Quantitative data from the results supply valuable references for Si-based strained device design.
