Dual-metal gate and gate–drain underlap designs are introduced to reduce the ambipolar current of the device based on the C-shaped pocket TFET(CSP-TFET).The effects of gate work function and gate–drain underlap leng...Dual-metal gate and gate–drain underlap designs are introduced to reduce the ambipolar current of the device based on the C-shaped pocket TFET(CSP-TFET).The effects of gate work function and gate–drain underlap length on the DC characteristics and analog/RF performance of CSP-TFET devices,such as the on-state current(I_(on)),ambipolar current(I_(amb)),transconductance(g_(m)),cut-off frequency(f_(T))and gain–bandwidth product(GBP),are analyzed and compared in this work.Also,a combination of both the dual-metal gate and gate–drain underlap designs has been proposed for the C-shaped pocket dual metal underlap TFET(CSP-DMUN-TFET),which contains a C-shaped pocket area that significantly increases the on-state current of the device;this combination design substantially reduces the ambipolar current.The results show that the CSP-DMUN-TFET demonstrates an excellent performance,including high I_(on)(9.03×10^(-4)A/μm),high I_(on)/I_(off)(~10^(11)),low SS_(avg)(~13 mV/dec),and low I_(amb)(2.15×10^(-17)A/μm).The CSP-DMUN-TFET has the capability to fully suppress ambipolar currents while maintaining high on-state currents,making it a potential replacement in the next generation of semiconductor devices.展开更多
The key technologies for the dual high-k and dual metal gate, such as the electrical optimization of metal insert poly-Si stack structure, the separating of high-k and metal gate of n/pMOS in different regions of the ...The key technologies for the dual high-k and dual metal gate, such as the electrical optimization of metal insert poly-Si stack structure, the separating of high-k and metal gate of n/pMOS in different regions of the wafer, and the synchronous etching of n/pMOS gate stack, are successfully developed. First, reasonable flat-band voltage and equivalent oxide thickness of pMOS MIPS structure are obtained by further optimizing the HfSiAlON dielectric through incorporating more Al-O dipole at interface between HfSiAlON and bottom SiOx. Then, the separating of high-k and metal gate for n/pMOS is achieved by SC1(NH4OH:H2O2:H2O = 1 : 1 : 5) and DHF-based solution for the selective removing of n MOS TaN and Hf Si ON and by BCl3-based plasma and DHF-based solution for the selective removing of pMOS TaN/Mo and HfSiAlON.After that, the synchronous etching of n/pMOS gate stack is developed by utilizing optimized BCl3/SF6/O2/Ar plasma to obtain a vertical profile for TaN and TaN/Mo and by utilizing BCl3/Ar plasma combined with DHF-based solution to achieve high selectivity to Si substrate. Finally, good electrical characteristics of CMOS devices, obtained by utilizing these new developed technologies, further confirm that they are practicable technologies for DHDMG integration.展开更多
Sub-threshold characteristics of the dual material gate 4H-SiC MESFET (DMGFET) are investigated and the analytical models to describe the drain-induced barrier lowering (DIBL) effect are derived by solving one- an...Sub-threshold characteristics of the dual material gate 4H-SiC MESFET (DMGFET) are investigated and the analytical models to describe the drain-induced barrier lowering (DIBL) effect are derived by solving one- and two- dimensional Poisson's equations. Using these models, we calculate the bottom potential of the channel and the threshold voltage shift, which characterize the drain-induced barrier lowering (DIBL) effect. The calculated results reveal that the dual material gate (DMG) structure alleviates the deterioration of the threshold voltage and thus suppresses the DIBL effect due to the introduced step function, which originates from the work function difference of the two gate materials when compared with the conventional single material gate metal-semiconductor field-effect transistor (SMGFET).展开更多
利用0.35μm工艺条件实现了性能优良的小尺寸全耗尽的器件硅绝缘体技术(SOI)互补金属氧化物半导体(FD SOI CMOS)器件,器件制作采用双多晶硅栅工艺、低掺杂浓度源/漏(LDD)结构以及突起的源漏区。这种结构的器件防止漏的击穿,减小短沟道效...利用0.35μm工艺条件实现了性能优良的小尺寸全耗尽的器件硅绝缘体技术(SOI)互补金属氧化物半导体(FD SOI CMOS)器件,器件制作采用双多晶硅栅工艺、低掺杂浓度源/漏(LDD)结构以及突起的源漏区。这种结构的器件防止漏的击穿,减小短沟道效应(SCE)和漏感应势垒降低效应(DIBL);突起的源漏区增加了源漏区的厚度并减小源漏区的串联电阻,增强了器件的电流驱动能力。设计了101级环形振荡器电路,并对该电路进行测试与分析。根据在3V工作电压下环形振荡器电路的振荡波形图,计算出其单级门延迟时间为45ps,远小于体硅CMOS的单级门延迟时间。展开更多
In this paper, the impact of extra electron source(EES) and dual metal gate engineering on conventional charge plasma TFET(CP-TFET) have been done for improving DC and analog/RF parameters. CP-TFET structure is upgrad...In this paper, the impact of extra electron source(EES) and dual metal gate engineering on conventional charge plasma TFET(CP-TFET) have been done for improving DC and analog/RF parameters. CP-TFET structure is upgraded to double source CP-TFET(DS-CP-TFET) by placing an EES below the source/channel junction for enhancing the device performance in terms of driving current and RF figures of merit(FOMs). But, in spite of these pros, the approach is having cons of higher leakage current similar to MOSFET and negative conductance(inherent nature of TFET). Both the issues have been resolved in the double source dual gate CP-TFET(DS-DG-CP-TFET) by gate workfunction engineering and drain underlapping respectively. Additionally,for getting the optimum performance of DS-DG-CP-TFET, the device sensitivity has been investigated in terms of position of EES,length of drain electrode and workfunction of gate electrode 1(GE1).展开更多
The present work gives some insight into the subthreshold behaviour of short-channel double-material- gate strained-silicon on silicon-germanium MOSFETs in terms of subthreshold swing and off-current. The formu- latio...The present work gives some insight into the subthreshold behaviour of short-channel double-material- gate strained-silicon on silicon-germanium MOSFETs in terms of subthreshold swing and off-current. The formu- lation of subthreshold current and, thereupon, the subthreshold swing have been done by exploiting the expression of potential distribution in the channel region of the device. The dependence of the subthreshold characteristics on the device parameters, such as Ge mole fraction, gate length ratio, work function of control gate metal and gate length, has been tested in detail. The analytical models have been validated by the numerical simulation results that were obtained from the device simulation software ATLASTM by Silvaco Inc.展开更多
In this paper TCAD-based simulation of a novel insulated shallow extension (ISE) cylindrical gate all around (CGAA) Schottky barrier (SB) MOSFET has been reported, to eliminate the suicidal ambipolar behavior (...In this paper TCAD-based simulation of a novel insulated shallow extension (ISE) cylindrical gate all around (CGAA) Schottky barrier (SB) MOSFET has been reported, to eliminate the suicidal ambipolar behavior (bias-dependent OFF state leakage current) of conventional SB-CGAA MOSFET by blocking the metal-induced gap states as well as unwanted charge sharing between source/channel and drain/channel regions. This novel structure offers low barrier height at the source and offers high ON-state current. The IoN/Iovr: of ISE-CGAA-SB-MOS- FET increases by 1177 times and offers steeper subthreshold slope (-60 mV/decade). However a little reduction in peak cut off frequency is observed and to further improve the cut-off frequency dual metal gate architecture has been employed and a comparative assessment of single metal gate, dual metal gate, single metal gate with ISE, and dual metal gate with ISE has been presented. The improved performance of Schottky barrier CGAA MOSFET by the incorporation of ISE makes it an attractive candidate for CMOS digital circuit design. The numerical simulation is performed using the ATLAS-3D device simulator.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.52177185 and 62174055)。
文摘Dual-metal gate and gate–drain underlap designs are introduced to reduce the ambipolar current of the device based on the C-shaped pocket TFET(CSP-TFET).The effects of gate work function and gate–drain underlap length on the DC characteristics and analog/RF performance of CSP-TFET devices,such as the on-state current(I_(on)),ambipolar current(I_(amb)),transconductance(g_(m)),cut-off frequency(f_(T))and gain–bandwidth product(GBP),are analyzed and compared in this work.Also,a combination of both the dual-metal gate and gate–drain underlap designs has been proposed for the C-shaped pocket dual metal underlap TFET(CSP-DMUN-TFET),which contains a C-shaped pocket area that significantly increases the on-state current of the device;this combination design substantially reduces the ambipolar current.The results show that the CSP-DMUN-TFET demonstrates an excellent performance,including high I_(on)(9.03×10^(-4)A/μm),high I_(on)/I_(off)(~10^(11)),low SS_(avg)(~13 mV/dec),and low I_(amb)(2.15×10^(-17)A/μm).The CSP-DMUN-TFET has the capability to fully suppress ambipolar currents while maintaining high on-state currents,making it a potential replacement in the next generation of semiconductor devices.
基金Project supported by the National High Technology Research and Development Program of China(Grant No.2015AA010601)
文摘The key technologies for the dual high-k and dual metal gate, such as the electrical optimization of metal insert poly-Si stack structure, the separating of high-k and metal gate of n/pMOS in different regions of the wafer, and the synchronous etching of n/pMOS gate stack, are successfully developed. First, reasonable flat-band voltage and equivalent oxide thickness of pMOS MIPS structure are obtained by further optimizing the HfSiAlON dielectric through incorporating more Al-O dipole at interface between HfSiAlON and bottom SiOx. Then, the separating of high-k and metal gate for n/pMOS is achieved by SC1(NH4OH:H2O2:H2O = 1 : 1 : 5) and DHF-based solution for the selective removing of n MOS TaN and Hf Si ON and by BCl3-based plasma and DHF-based solution for the selective removing of pMOS TaN/Mo and HfSiAlON.After that, the synchronous etching of n/pMOS gate stack is developed by utilizing optimized BCl3/SF6/O2/Ar plasma to obtain a vertical profile for TaN and TaN/Mo and by utilizing BCl3/Ar plasma combined with DHF-based solution to achieve high selectivity to Si substrate. Finally, good electrical characteristics of CMOS devices, obtained by utilizing these new developed technologies, further confirm that they are practicable technologies for DHDMG integration.
基金Project supported by the Pre-research Foundation from the National Ministries and Commissions of China (GrantNo.51308030201)
文摘Sub-threshold characteristics of the dual material gate 4H-SiC MESFET (DMGFET) are investigated and the analytical models to describe the drain-induced barrier lowering (DIBL) effect are derived by solving one- and two- dimensional Poisson's equations. Using these models, we calculate the bottom potential of the channel and the threshold voltage shift, which characterize the drain-induced barrier lowering (DIBL) effect. The calculated results reveal that the dual material gate (DMG) structure alleviates the deterioration of the threshold voltage and thus suppresses the DIBL effect due to the introduced step function, which originates from the work function difference of the two gate materials when compared with the conventional single material gate metal-semiconductor field-effect transistor (SMGFET).
文摘利用0.35μm工艺条件实现了性能优良的小尺寸全耗尽的器件硅绝缘体技术(SOI)互补金属氧化物半导体(FD SOI CMOS)器件,器件制作采用双多晶硅栅工艺、低掺杂浓度源/漏(LDD)结构以及突起的源漏区。这种结构的器件防止漏的击穿,减小短沟道效应(SCE)和漏感应势垒降低效应(DIBL);突起的源漏区增加了源漏区的厚度并减小源漏区的串联电阻,增强了器件的电流驱动能力。设计了101级环形振荡器电路,并对该电路进行测试与分析。根据在3V工作电压下环形振荡器电路的振荡波形图,计算出其单级门延迟时间为45ps,远小于体硅CMOS的单级门延迟时间。
文摘In this paper, the impact of extra electron source(EES) and dual metal gate engineering on conventional charge plasma TFET(CP-TFET) have been done for improving DC and analog/RF parameters. CP-TFET structure is upgraded to double source CP-TFET(DS-CP-TFET) by placing an EES below the source/channel junction for enhancing the device performance in terms of driving current and RF figures of merit(FOMs). But, in spite of these pros, the approach is having cons of higher leakage current similar to MOSFET and negative conductance(inherent nature of TFET). Both the issues have been resolved in the double source dual gate CP-TFET(DS-DG-CP-TFET) by gate workfunction engineering and drain underlapping respectively. Additionally,for getting the optimum performance of DS-DG-CP-TFET, the device sensitivity has been investigated in terms of position of EES,length of drain electrode and workfunction of gate electrode 1(GE1).
文摘The present work gives some insight into the subthreshold behaviour of short-channel double-material- gate strained-silicon on silicon-germanium MOSFETs in terms of subthreshold swing and off-current. The formu- lation of subthreshold current and, thereupon, the subthreshold swing have been done by exploiting the expression of potential distribution in the channel region of the device. The dependence of the subthreshold characteristics on the device parameters, such as Ge mole fraction, gate length ratio, work function of control gate metal and gate length, has been tested in detail. The analytical models have been validated by the numerical simulation results that were obtained from the device simulation software ATLASTM by Silvaco Inc.
基金UGC,Government of India for providing the necessary financial support
文摘In this paper TCAD-based simulation of a novel insulated shallow extension (ISE) cylindrical gate all around (CGAA) Schottky barrier (SB) MOSFET has been reported, to eliminate the suicidal ambipolar behavior (bias-dependent OFF state leakage current) of conventional SB-CGAA MOSFET by blocking the metal-induced gap states as well as unwanted charge sharing between source/channel and drain/channel regions. This novel structure offers low barrier height at the source and offers high ON-state current. The IoN/Iovr: of ISE-CGAA-SB-MOS- FET increases by 1177 times and offers steeper subthreshold slope (-60 mV/decade). However a little reduction in peak cut off frequency is observed and to further improve the cut-off frequency dual metal gate architecture has been employed and a comparative assessment of single metal gate, dual metal gate, single metal gate with ISE, and dual metal gate with ISE has been presented. The improved performance of Schottky barrier CGAA MOSFET by the incorporation of ISE makes it an attractive candidate for CMOS digital circuit design. The numerical simulation is performed using the ATLAS-3D device simulator.