A novel fully-depleted dual-gate MOSFET with a hetero-material gate and a lightly-doped drain is proposed. The hetero-material gate, which consists of a main gate and two side-gates,is used to control the surface pote...A novel fully-depleted dual-gate MOSFET with a hetero-material gate and a lightly-doped drain is proposed. The hetero-material gate, which consists of a main gate and two side-gates,is used to control the surface potential distribution. The fabrication process and the device characteristics are simulated with Tsuprem-4 and Medici separately. Compared to a common DG fully depleted SO1 MOSFET,the proposed device has much higher on/off current ratio and superior sub-threshold slope. The on/off current ratio is about 10^10 and the sub-threshold slope is nearly 60mV/dec under a 0.18μm process.展开更多
给出了几种 Ga As MESFET单片混频器结构与芯片测试结果比较。实验表明 ,在相同本振功率激励下 Ga As MMIC双栅混频器具有良好变频特性 ,栅混频器指标次之 ,漏混频器结构最简单 ,但变频特性不如前两种。另外 ,单片巴仑双平衡混频器具有...给出了几种 Ga As MESFET单片混频器结构与芯片测试结果比较。实验表明 ,在相同本振功率激励下 Ga As MMIC双栅混频器具有良好变频特性 ,栅混频器指标次之 ,漏混频器结构最简单 ,但变频特性不如前两种。另外 ,单片巴仑双平衡混频器具有高的动态范围和宽频段工作特点。展开更多
A vertically movable gate field effect transistor(VMGFET) is proposed and demonstrated for a microaccelerometer application. The VMGFET using air gap as an insulator layer allows the gate to move on the substrate vert...A vertically movable gate field effect transistor(VMGFET) is proposed and demonstrated for a microaccelerometer application. The VMGFET using air gap as an insulator layer allows the gate to move on the substrate vertically by external forces. Finite element analysis is used to simulate mechanical behaviors of the designed structure. For the simulation, the ground acceleration spectrum of the 1952 Kern County Earthquake is employed to investigate the structural integrity of the sensor in vibration. Based on the simulation, a prototype VMGFET accelerometer is fabricated from silicon on insulator wafer. According to current–voltage characteristics of the prototype VMGFET, the threshold voltage is measured to be 2.32 V, which determines the effective charge density and the mutual transconductance of1.545910-8C cm-2and 6.59 m A V-1, respectively. The device sensitivity is 9.36–9.42 m V g-1in the low frequency,and the first natural frequency is found to be 1230 Hz. The profile smoothness of the sensed signal is in 3 d B range up to1 k Hz.展开更多
The fluorine ion sensitive field-effect transistor（F<sup>-</sup>-ISFET）is made by depositingvery thin LaF<sub>3</sub> film on grid of field-effect transistor with sputter method.The operating...The fluorine ion sensitive field-effect transistor（F<sup>-</sup>-ISFET）is made by depositingvery thin LaF<sub>3</sub> film on grid of field-effect transistor with sputter method.The operating principle,measuring method and measured results of F<sup>-</sup>-ISFET are given.The measured results show thatthis kind of sensor has higher sensitivity,shorter response time and better linearity.On the basisof experimental results,the factor of influencing the steadiness and repeatability of F<sup>-</sup>-ISFETare conjectured.展开更多
A physically based analytical model for surface potential and threshold voltage including the fringing gate capacitances in cylindrical surround gate（CSG） MOSFETs has been developed.Based on this a subthreshold drai...A physically based analytical model for surface potential and threshold voltage including the fringing gate capacitances in cylindrical surround gate（CSG） MOSFETs has been developed.Based on this a subthreshold drain current model has also been derived.This model first computes the charge induced in the drain/source region due to the fringing capacitances and considers an effective charge distribution in the cylindrically extended source/drain region for the development of a simple and compact model.The fringing gate capacitances taken into account are outer fringe capacitance,inner fringe capacitance,overlap capacitance,and sidewall capacitance.The model has been verified with the data extracted from 3D TCAD simulations of CSG MOSFETs and was found to be working satisfactorily.展开更多
In this paper,RF performance analysis of In As-based double gate（DG）tunnel field effect transistors（TFETs）is investigated in both qualitative and quantitative fashion.This investigation is carried out by varying t...In this paper,RF performance analysis of In As-based double gate（DG）tunnel field effect transistors（TFETs）is investigated in both qualitative and quantitative fashion.This investigation is carried out by varying the geometrical and doping parameters of TFETs to extract various RF parameters,unity gain cut-off frequency（f_t）,maximum oscillation frequency（f_（max））,intrinsic gain and admittance（Y）parameters.An asymmetric gate oxide is introduced in the gate-drain overlap and compared with that of DG TFETs.Higher ON-current（ION）of about 0.2 mA and less leakage current（IOFF）of 29 f A is achieved for DG TFET with gate-drain overlap.Due to increase in transconductance（g_m）,higher ft and intrinsic gain is attained for DG TFET with gate-drain overlap.Higher f_（max） of 985 GHz is obtained for drain doping of 5×10^（17）cm^（-3） because of the reduced gate-drain capacitance（C_（gd））with DG TFET with gate-drain overlap.In terms of Y-parameters,gate oxide thickness variation offers better performance due to the reduced values of Cgd.A second order numerical polynomial model is generated for all the RF responses as a function of geometrical and doping parameters.The simulation results are compared with this numerical model where the predicted values match with the simulated values.展开更多
Comparisons are performed to study the drive current of accumulation-mode（AM） p-channel wrap-gated Fin-FETs.The drive current of the AM p-channel FET is 15%-26%larger than that of the inversion-mode （IM） p-channel...Comparisons are performed to study the drive current of accumulation-mode（AM） p-channel wrap-gated Fin-FETs.The drive current of the AM p-channel FET is 15%-26%larger than that of the inversion-mode （IM） p-channel FET with the same wrap-gated fin channel,because of the body current component in the AM FET, which becomes less dominative as the gate overdrive becomes larger.The drive currents of the AM p-channel wrap-gated Fin-FETs are 50%larger than those of the AM p-channel planar FETs,which arises from effective conducting surface broadening and volume accumulation in the AM wrap-gated Fin-FETs.The effective conducting surface broadening is due to wrap-gate-induced multi-surface conduction,while the volume accumulation,namely the majority carrier concentration anywhere in the fin cross section exceeding the fin doping density,is due to the coupling of electric fields from different parts of the wrap gate.Moreover,for AM p-channel wrap-gated Fin-FETs, the current in channel along 110 is larger than that in channel along 100,which arises from the surface mobility difference due to different transport directions and surface orientations.That is more obvious as the gate overdrive becomes larger,when the surface current component plays a more dominative role in the total current.展开更多
文摘A novel fully-depleted dual-gate MOSFET with a hetero-material gate and a lightly-doped drain is proposed. The hetero-material gate, which consists of a main gate and two side-gates,is used to control the surface potential distribution. The fabrication process and the device characteristics are simulated with Tsuprem-4 and Medici separately. Compared to a common DG fully depleted SO1 MOSFET,the proposed device has much higher on/off current ratio and superior sub-threshold slope. The on/off current ratio is about 10^10 and the sub-threshold slope is nearly 60mV/dec under a 0.18μm process.
基金supported by the National Research Foundation of Korea(NRF)funded by the Korea government(MSIP)(No.2012M2A8A5025825)
文摘A vertically movable gate field effect transistor(VMGFET) is proposed and demonstrated for a microaccelerometer application. The VMGFET using air gap as an insulator layer allows the gate to move on the substrate vertically by external forces. Finite element analysis is used to simulate mechanical behaviors of the designed structure. For the simulation, the ground acceleration spectrum of the 1952 Kern County Earthquake is employed to investigate the structural integrity of the sensor in vibration. Based on the simulation, a prototype VMGFET accelerometer is fabricated from silicon on insulator wafer. According to current–voltage characteristics of the prototype VMGFET, the threshold voltage is measured to be 2.32 V, which determines the effective charge density and the mutual transconductance of1.545910-8C cm-2and 6.59 m A V-1, respectively. The device sensitivity is 9.36–9.42 m V g-1in the low frequency,and the first natural frequency is found to be 1230 Hz. The profile smoothness of the sensed signal is in 3 d B range up to1 k Hz.
文摘The fluorine ion sensitive field-effect transistor（F<sup>-</sup>-ISFET）is made by depositingvery thin LaF<sub>3</sub> film on grid of field-effect transistor with sputter method.The operating principle,measuring method and measured results of F<sup>-</sup>-ISFET are given.The measured results show thatthis kind of sensor has higher sensitivity,shorter response time and better linearity.On the basisof experimental results,the factor of influencing the steadiness and repeatability of F<sup>-</sup>-ISFETare conjectured.
基金Project supported by the AICTE(No.8023/BOR/RID/RPS-253/2008-09)the SMDP-Ⅱ Project(No.21(1)/2005-VCND) by MCIT, DeiTy,Govt of India
文摘A physically based analytical model for surface potential and threshold voltage including the fringing gate capacitances in cylindrical surround gate（CSG） MOSFETs has been developed.Based on this a subthreshold drain current model has also been derived.This model first computes the charge induced in the drain/source region due to the fringing capacitances and considers an effective charge distribution in the cylindrically extended source/drain region for the development of a simple and compact model.The fringing gate capacitances taken into account are outer fringe capacitance,inner fringe capacitance,overlap capacitance,and sidewall capacitance.The model has been verified with the data extracted from 3D TCAD simulations of CSG MOSFETs and was found to be working satisfactorily.
基金Project supported by the Department of Science and Technology,Government of India under SERB Scheme(No.SERB/F/2660)
文摘In this paper,RF performance analysis of In As-based double gate（DG）tunnel field effect transistors（TFETs）is investigated in both qualitative and quantitative fashion.This investigation is carried out by varying the geometrical and doping parameters of TFETs to extract various RF parameters,unity gain cut-off frequency（f_t）,maximum oscillation frequency（f_（max））,intrinsic gain and admittance（Y）parameters.An asymmetric gate oxide is introduced in the gate-drain overlap and compared with that of DG TFETs.Higher ON-current（ION）of about 0.2 mA and less leakage current（IOFF）of 29 f A is achieved for DG TFET with gate-drain overlap.Due to increase in transconductance（g_m）,higher ft and intrinsic gain is attained for DG TFET with gate-drain overlap.Higher f_（max） of 985 GHz is obtained for drain doping of 5×10^（17）cm^（-3） because of the reduced gate-drain capacitance（C_（gd））with DG TFET with gate-drain overlap.In terms of Y-parameters,gate oxide thickness variation offers better performance due to the reduced values of Cgd.A second order numerical polynomial model is generated for all the RF responses as a function of geometrical and doping parameters.The simulation results are compared with this numerical model where the predicted values match with the simulated values.
基金Project supported by the National High Technology Research and Development Program of China(No.2007AA03Z303)the National Basic Research Program of China(No.2010CB934104)
文摘Comparisons are performed to study the drive current of accumulation-mode（AM） p-channel wrap-gated Fin-FETs.The drive current of the AM p-channel FET is 15%-26%larger than that of the inversion-mode （IM） p-channel FET with the same wrap-gated fin channel,because of the body current component in the AM FET, which becomes less dominative as the gate overdrive becomes larger.The drive currents of the AM p-channel wrap-gated Fin-FETs are 50%larger than those of the AM p-channel planar FETs,which arises from effective conducting surface broadening and volume accumulation in the AM wrap-gated Fin-FETs.The effective conducting surface broadening is due to wrap-gate-induced multi-surface conduction,while the volume accumulation,namely the majority carrier concentration anywhere in the fin cross section exceeding the fin doping density,is due to the coupling of electric fields from different parts of the wrap gate.Moreover,for AM p-channel wrap-gated Fin-FETs, the current in channel along 110 is larger than that in channel along 100,which arises from the surface mobility difference due to different transport directions and surface orientations.That is more obvious as the gate overdrive becomes larger,when the surface current component plays a more dominative role in the total current.
