The 28 nm process has a high cost-performance ratio and has gradually become the standard for the field of radiation-hardened devices.However,owing to the minimum physical gate length of only 35 nm,the physical area o...The 28 nm process has a high cost-performance ratio and has gradually become the standard for the field of radiation-hardened devices.However,owing to the minimum physical gate length of only 35 nm,the physical area of a standard 6T SRAM unit is approximately 0.16μm^(2),resulting in a significant enhancement of multi-cell charge-sharing effects.Multiple-cell upsets(MCUs)have become the primary physical mechanism behind single-event upsets(SEUs)in advanced nanometer node devices.The range of ionization track effects increases with higher ion energies,and spacecraft in orbit primarily experience SEUs caused by high-energy ions.However,ground accelerator experiments have mainly obtained low-energy ion irradiation data.Therefore,the impact of ion energy on the SEU cross section,charge collection mechanisms,and MCU patterns and quantities in advanced nanometer devices remains unclear.In this study,based on the experimental platform of the Heavy Ion Research Facility in Lanzhou,low-and high-energy heavy-ion beams were used to study the SEUs of 28 nm SRAM devices.The influence of ion energy on the charge collection processes of small-sensitive-volume devices,MCU patterns,and upset cross sections was obtained,and the applicable range of the inverse cosine law was clarified.The findings of this study are an important guide for the accurate evaluation of SEUs in advanced nanometer devices and for the development of radiation-hardening techniques.展开更多
The pulsed laser facility for SEU sensitivity mapping is utilized to study the SEU sensitive regions of a 0.18/zm CMOS SRAM cell. Combined with the device layout micrograph, SEU sensitivity maps of the SRAM cell are o...The pulsed laser facility for SEU sensitivity mapping is utilized to study the SEU sensitive regions of a 0.18/zm CMOS SRAM cell. Combined with the device layout micrograph, SEU sensitivity maps of the SRAM cell are obtained. TCAD simulation work is performed to examine the SEU sensitivity characteristics of the SRAM cell. The laser mapping experiment results are discussed and compared with the electron micrograph information of the SRAM cell and the TCAD simulation results. The results present that the test technique is reliable and of high mapping precision for the deep submicron technology device.展开更多
为提升SRAM型FPGA电路块存储器和配置存储器抗单粒子翻转性能,本文提出一种脉冲屏蔽SRAM单元结构。该结构通过在标准的六管单元中加入延迟结构,增大单元对单粒子事件响应时间,实现对粒子入射产生的脉冲电流屏蔽作用。以64k SRAM作为验...为提升SRAM型FPGA电路块存储器和配置存储器抗单粒子翻转性能,本文提出一种脉冲屏蔽SRAM单元结构。该结构通过在标准的六管单元中加入延迟结构,增大单元对单粒子事件响应时间,实现对粒子入射产生的脉冲电流屏蔽作用。以64k SRAM作为验证电路进行单粒子翻转性能对比,电路的抗单粒子翻转阈值由采用标准六管单元的抗单粒子翻转阈值大于25 Me V·cm2·mg-1提升至大于45 Me V·cm2·mg-1,加固单元面积较标准六管单元增大约21.3%。30万门级抗辐照FPGA电路通过脉冲屏蔽单元结合抗辐照SOI工艺实现,其抗辐照指标分别为:抗单粒子翻转阈值大于37.3 Me V·cm2·mg-1,抗单粒子锁定阈值大于99.8 Me V·cm2·mg-1,抗电离总剂量能力大于200 krad(Si)。展开更多
Low power supply operation with leakage power reduction is the prime concern in modern nano-scale CMOS memory devices. In the present scenario, low leakage memory architecture becomes more challenging, as it has 30% o...Low power supply operation with leakage power reduction is the prime concern in modern nano-scale CMOS memory devices. In the present scenario, low leakage memory architecture becomes more challenging, as it has 30% of the total chip power consumption. Since, the SRAM cell is low in density and most of memory processing data remain stable during the data holding operation, the stored memory data are more affected by the leakage phenomena in the circuit while the device parameters are scaled down. In this survey, origins of leakage currents in a short-channel device and various leakage control techniques for ultra-low power SRAM design are discussed. A classification of these approaches made based on their key design and functions, such as biasing technique, power gating and multi-threshold techniques. Based on our survey, we summarize the merits and demerits and challenges of these techniques. This comprehensive study will be helpful to extend the further research for future implementations.展开更多
This paper proposes a novel loadless 4T SRAM cell composed of nMOS transistors. The SRAM cell is based on 32nm silicon-on-insulator （SO1） technology node. It consists of two access transistors and two pull-down tran...This paper proposes a novel loadless 4T SRAM cell composed of nMOS transistors. The SRAM cell is based on 32nm silicon-on-insulator （SO1） technology node. It consists of two access transistors and two pull-down transistors. The pull-down transistors have larger channel length than the access transistors. Due to the significant short channel effect of small-size MOS transistors, the access transistors have much larger leakage current than the pull-down transistors,enabling the SRAM cell to maintain logic ＂1＂ while in standby. The storage node voltages of the cell are fed back to the back-gates of the access transistors,enabling the stable ＂read＂ operation of the cell. The use of back-gate feedback also helps to im- prove the static noise margin （SNM） of the cell. The proposed SRAM cell has smaller area than conventional bulk 6T SRAM cells and 4T SRAM cells. The speed and power dissipation of the SRAM cell are simulated and discussed. The SRAM cell can operate with a 0. 5V supply voltage.展开更多
动态电压频率调整(Dynamic Voltage Frequency Scaling,DVFS)可以使系统在高电压工作时获得高性能,在低电压工作时降低系统功耗,它要求电路能够从正常电压一直到亚阈值区范围内均能正常工作.抗辐照DVFSSRAM的设计面临着低压工作稳定性...动态电压频率调整(Dynamic Voltage Frequency Scaling,DVFS)可以使系统在高电压工作时获得高性能,在低电压工作时降低系统功耗,它要求电路能够从正常电压一直到亚阈值区范围内均能正常工作.抗辐照DVFSSRAM的设计面临着低压工作稳定性及工艺、电压、温度偏差(Process,Voltage,Temperature,PVT)的严重影响.本文针对以上问题,设计了一款适应于DVFS应用的抗辐照静态随机存储器(Static Random Access Memory,SRAM).提出了新型抗辐照DICE单元结构,其读噪声容限相对于原有DICE单元有大幅提升.同时,针对常规分级位线结构时序控制电路存在的问题,提出了改进型复制列技术,增强了SRAM存储体在不同PVT环境下工作的稳定性.对SRAM存储体进行了电路设计及版图设计,后仿真结果表明,设计的512bit SRAM存储体可在0.6V^1.8V电源电压下正常工作.在1.8V下,SRAM的存取速度为5.1ns,功耗为1.8mW;在0.6V电压下,SRAM的存取速度为93.5ns,功耗为14.63μW,比1.8 V电源工作时的功耗降低了约100倍.另外,设计的SRAM对宽度为300ps以下的单粒子瞬态脉冲具有滤除能力,对单粒子翻转效应有良好的抵抗能力.展开更多
A modified four transistor （4T） self-body-bias structured SRAM/SOI memory cell is proposed. The structure is designed and its parameters are obtained by performance simulation and analysis with TSUPREM4 and MEDICI.T...A modified four transistor （4T） self-body-bias structured SRAM/SOI memory cell is proposed. The structure is designed and its parameters are obtained by performance simulation and analysis with TSUPREM4 and MEDICI.The structure saves area and its process is simplified by using the body resistor with buried p^＋ channel beneath the nMOS gate instead of the pMOS of 6T CMOS SRAM. Furthermore, this structure can operate safely with a 0.5V supply voltage, which may be prevalent in the near future. Finally, compared to conventional 6T CMOS SRAM,this structure＇s transient responses are normal and its power dissipation is 10 times smaller.展开更多
基金supported by the National Natural Science Foundation of China(Nos.12105341 and 12035019)the opening fund of Key Laboratory of Silicon Device and Technology,Chinese Academy of Sciences(No.KLSDTJJ2022-3).
文摘The 28 nm process has a high cost-performance ratio and has gradually become the standard for the field of radiation-hardened devices.However,owing to the minimum physical gate length of only 35 nm,the physical area of a standard 6T SRAM unit is approximately 0.16μm^(2),resulting in a significant enhancement of multi-cell charge-sharing effects.Multiple-cell upsets(MCUs)have become the primary physical mechanism behind single-event upsets(SEUs)in advanced nanometer node devices.The range of ionization track effects increases with higher ion energies,and spacecraft in orbit primarily experience SEUs caused by high-energy ions.However,ground accelerator experiments have mainly obtained low-energy ion irradiation data.Therefore,the impact of ion energy on the SEU cross section,charge collection mechanisms,and MCU patterns and quantities in advanced nanometer devices remains unclear.In this study,based on the experimental platform of the Heavy Ion Research Facility in Lanzhou,low-and high-energy heavy-ion beams were used to study the SEUs of 28 nm SRAM devices.The influence of ion energy on the charge collection processes of small-sensitive-volume devices,MCU patterns,and upset cross sections was obtained,and the applicable range of the inverse cosine law was clarified.The findings of this study are an important guide for the accurate evaluation of SEUs in advanced nanometer devices and for the development of radiation-hardening techniques.
基金Project supported by the Industrial Technology Development Program of China(No.A1320110028)the Key Programs of the Chinese Academy of Sciences(No.110161501038)
文摘The pulsed laser facility for SEU sensitivity mapping is utilized to study the SEU sensitive regions of a 0.18/zm CMOS SRAM cell. Combined with the device layout micrograph, SEU sensitivity maps of the SRAM cell are obtained. TCAD simulation work is performed to examine the SEU sensitivity characteristics of the SRAM cell. The laser mapping experiment results are discussed and compared with the electron micrograph information of the SRAM cell and the TCAD simulation results. The results present that the test technique is reliable and of high mapping precision for the deep submicron technology device.
文摘为提升SRAM型FPGA电路块存储器和配置存储器抗单粒子翻转性能,本文提出一种脉冲屏蔽SRAM单元结构。该结构通过在标准的六管单元中加入延迟结构,增大单元对单粒子事件响应时间,实现对粒子入射产生的脉冲电流屏蔽作用。以64k SRAM作为验证电路进行单粒子翻转性能对比,电路的抗单粒子翻转阈值由采用标准六管单元的抗单粒子翻转阈值大于25 Me V·cm2·mg-1提升至大于45 Me V·cm2·mg-1,加固单元面积较标准六管单元增大约21.3%。30万门级抗辐照FPGA电路通过脉冲屏蔽单元结合抗辐照SOI工艺实现,其抗辐照指标分别为:抗单粒子翻转阈值大于37.3 Me V·cm2·mg-1,抗单粒子锁定阈值大于99.8 Me V·cm2·mg-1,抗电离总剂量能力大于200 krad(Si)。
文摘Low power supply operation with leakage power reduction is the prime concern in modern nano-scale CMOS memory devices. In the present scenario, low leakage memory architecture becomes more challenging, as it has 30% of the total chip power consumption. Since, the SRAM cell is low in density and most of memory processing data remain stable during the data holding operation, the stored memory data are more affected by the leakage phenomena in the circuit while the device parameters are scaled down. In this survey, origins of leakage currents in a short-channel device and various leakage control techniques for ultra-low power SRAM design are discussed. A classification of these approaches made based on their key design and functions, such as biasing technique, power gating and multi-threshold techniques. Based on our survey, we summarize the merits and demerits and challenges of these techniques. This comprehensive study will be helpful to extend the further research for future implementations.
文摘This paper proposes a novel loadless 4T SRAM cell composed of nMOS transistors. The SRAM cell is based on 32nm silicon-on-insulator （SO1） technology node. It consists of two access transistors and two pull-down transistors. The pull-down transistors have larger channel length than the access transistors. Due to the significant short channel effect of small-size MOS transistors, the access transistors have much larger leakage current than the pull-down transistors,enabling the SRAM cell to maintain logic ＂1＂ while in standby. The storage node voltages of the cell are fed back to the back-gates of the access transistors,enabling the stable ＂read＂ operation of the cell. The use of back-gate feedback also helps to im- prove the static noise margin （SNM） of the cell. The proposed SRAM cell has smaller area than conventional bulk 6T SRAM cells and 4T SRAM cells. The speed and power dissipation of the SRAM cell are simulated and discussed. The SRAM cell can operate with a 0. 5V supply voltage.
文摘动态电压频率调整(Dynamic Voltage Frequency Scaling,DVFS)可以使系统在高电压工作时获得高性能,在低电压工作时降低系统功耗,它要求电路能够从正常电压一直到亚阈值区范围内均能正常工作.抗辐照DVFSSRAM的设计面临着低压工作稳定性及工艺、电压、温度偏差(Process,Voltage,Temperature,PVT)的严重影响.本文针对以上问题,设计了一款适应于DVFS应用的抗辐照静态随机存储器(Static Random Access Memory,SRAM).提出了新型抗辐照DICE单元结构,其读噪声容限相对于原有DICE单元有大幅提升.同时,针对常规分级位线结构时序控制电路存在的问题,提出了改进型复制列技术,增强了SRAM存储体在不同PVT环境下工作的稳定性.对SRAM存储体进行了电路设计及版图设计,后仿真结果表明,设计的512bit SRAM存储体可在0.6V^1.8V电源电压下正常工作.在1.8V下,SRAM的存取速度为5.1ns,功耗为1.8mW;在0.6V电压下,SRAM的存取速度为93.5ns,功耗为14.63μW,比1.8 V电源工作时的功耗降低了约100倍.另外,设计的SRAM对宽度为300ps以下的单粒子瞬态脉冲具有滤除能力,对单粒子翻转效应有良好的抵抗能力.
文摘A modified four transistor （4T） self-body-bias structured SRAM/SOI memory cell is proposed. The structure is designed and its parameters are obtained by performance simulation and analysis with TSUPREM4 and MEDICI.The structure saves area and its process is simplified by using the body resistor with buried p^＋ channel beneath the nMOS gate instead of the pMOS of 6T CMOS SRAM. Furthermore, this structure can operate safely with a 0.5V supply voltage, which may be prevalent in the near future. Finally, compared to conventional 6T CMOS SRAM,this structure＇s transient responses are normal and its power dissipation is 10 times smaller.
