A comprehensive way to design a sub 50nm SADG MOSFET with the ability of being fabricated by improved CMOS technique is described.Under this way,the gate length and thickness of Si island of DG device show many diffe...A comprehensive way to design a sub 50nm SADG MOSFET with the ability of being fabricated by improved CMOS technique is described.Under this way,the gate length and thickness of Si island of DG device show many different scaling limits for various elements.Meanwhile,the spacer insulator shows a kind of width thickness on device drain current and circuit speed.A model about that effect is developed and offers design consideration for future.A new design of channel doping profile,called SCD,is also discussed here in detail.The DG device with SCD can achieve a good balance between the volume inversion operation mode and the control of V th .Finally,a guideline to make a SADG MOSFET is presented.展开更多
The analytical solutions to 1D Schrdinger equation (in depth direction) in double gate (DG) MOSFETs are derived to calculate electron density and threshold voltage.The non uniform potential in the channel is concern...The analytical solutions to 1D Schrdinger equation (in depth direction) in double gate (DG) MOSFETs are derived to calculate electron density and threshold voltage.The non uniform potential in the channel is concerned with an arbitrary depth so that the analytical solutions agree well with numerical ones.Then,an implicit expression for electron density and a closed form of threshold voltage are presented fully comprising quantum mechanical (QM) effects.This model predicts an increased electron density with an increasing channel depth in subthreshold region or mild inversion region.However,it becomes independent on channel depth in strong inversion region,which is in accordance with numerical analysis.It is also concluded that the QM model,which barely considers a box like potential in the channel,slightly over predicts threshold voltage and underestimates electron density,and the error increases with an increasing channel depth or a decreasing gate oxide thickness.展开更多
A surface potential-based model for undoped symmetric double-gate MOSFETs is derived by solving Poisson＇s equation to obtain the relationship between the surface potential and voltage in the channel region in a self-...A surface potential-based model for undoped symmetric double-gate MOSFETs is derived by solving Poisson＇s equation to obtain the relationship between the surface potential and voltage in the channel region in a self-consistent way. The drain current expression is then obtained from Pao-Sah＇s double integral. The model consists of one set of surface potential equations,and the analytic drain current can be evaluated from the surface potential at the source and drain ends. It is demonstrated that the model is valid for all operation regions of the double-gate MOSFETs and without any need for simplification （e. g., by using the charge sheet assumption） or auxiliary fitting functions. The model has been verified by extensive comparisons with 2D numerical simulation under different operation conditions with different geometries. The consistency between the model calculation and numerical simulation demonstrates the accuracy of the model.展开更多
In this paper, we study the effects of an unintended dopant in the channel on the current-voltage char-acteristics of a Double-Gate (DG) Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET). Non-Equilibrium Gree...In this paper, we study the effects of an unintended dopant in the channel on the current-voltage char-acteristics of a Double-Gate (DG) Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET). Non-Equilibrium Green's Function (NEGF) approach is used. A quantum transport model to calculate the drain current is presented and subthreshold swing and drain induced barrier lowering (DIBL) effect are studied.展开更多
基金National Natural Science Foundation of China under National Outstanding Young Scientist Award (60788402)National Science Foundation of China (60976067)Fundamental Research Funds for the Central Universities (3101033,1101001,3104009)
文摘A comprehensive way to design a sub 50nm SADG MOSFET with the ability of being fabricated by improved CMOS technique is described.Under this way,the gate length and thickness of Si island of DG device show many different scaling limits for various elements.Meanwhile,the spacer insulator shows a kind of width thickness on device drain current and circuit speed.A model about that effect is developed and offers design consideration for future.A new design of channel doping profile,called SCD,is also discussed here in detail.The DG device with SCD can achieve a good balance between the volume inversion operation mode and the control of V th .Finally,a guideline to make a SADG MOSFET is presented.
文摘The analytical solutions to 1D Schrdinger equation (in depth direction) in double gate (DG) MOSFETs are derived to calculate electron density and threshold voltage.The non uniform potential in the channel is concerned with an arbitrary depth so that the analytical solutions agree well with numerical ones.Then,an implicit expression for electron density and a closed form of threshold voltage are presented fully comprising quantum mechanical (QM) effects.This model predicts an increased electron density with an increasing channel depth in subthreshold region or mild inversion region.However,it becomes independent on channel depth in strong inversion region,which is in accordance with numerical analysis.It is also concluded that the QM model,which barely considers a box like potential in the channel,slightly over predicts threshold voltage and underestimates electron density,and the error increases with an increasing channel depth or a decreasing gate oxide thickness.
基金the National Natural Science Foundation of China(No.90607017)the Competitive Ear marked Grant 611207 from the Research Grant Council of Hong Kong SARthe International Joint Research Program(NEDO Grant)from Japan(No.NEDOO5/06.EG01)~~
文摘A surface potential-based model for undoped symmetric double-gate MOSFETs is derived by solving Poisson＇s equation to obtain the relationship between the surface potential and voltage in the channel region in a self-consistent way. The drain current expression is then obtained from Pao-Sah＇s double integral. The model consists of one set of surface potential equations,and the analytic drain current can be evaluated from the surface potential at the source and drain ends. It is demonstrated that the model is valid for all operation regions of the double-gate MOSFETs and without any need for simplification （e. g., by using the charge sheet assumption） or auxiliary fitting functions. The model has been verified by extensive comparisons with 2D numerical simulation under different operation conditions with different geometries. The consistency between the model calculation and numerical simulation demonstrates the accuracy of the model.
基金Supported of National Natural Science Foundation of China under Grant Nos. 61171010 and 61171011the State Key Laboratory of ASIC and System is Appreciated under Grant No. 11MS015the Special Funds for Major State Basic Research (973) under Grant No. 2011CBA00603
文摘In this paper, we study the effects of an unintended dopant in the channel on the current-voltage char-acteristics of a Double-Gate (DG) Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET). Non-Equilibrium Green's Function (NEGF) approach is used. A quantum transport model to calculate the drain current is presented and subthreshold swing and drain induced barrier lowering (DIBL) effect are studied.
