一种全nMoS SOI晶体管4管静态存储器单元

提出了一种新颖的无负载4管全部由nMOS管组成的随机静态存储器(SRAM)单元.该SRAM单元基于32nm绝缘体上硅(SOI)工艺结点,它包含有两个存取管和两个下拉管.存取管的沟道长度小于下拉管的沟道长度.由于小尺寸MOS管的短沟道效应,在关闭状态时存取管具有远大于下拉管的漏电流,从而使SRAM单元在保持状态下可以维持逻辑"1".存储节点的电压还被反馈到存取管的背栅上,使SRAM单元具有稳定的"读"操作.背栅反馈同时增强了SRAM单元的静态噪声容限(SNM).该单元比传统的6管SRAM单元和4管SRAM单元具有更小的面积.对SRAM单元的读写速度和功耗做了仿真和讨论.该SRAM单元可以工作在0.5V电源电压下.     

A Low Power SRAM/SOI Memory Cell Design

提出一种改进4管自体偏压结构SRAM/SOI单元. 基于TSUPREM4和MEDICI软件的模拟和结构性能的分析，设计单元结构并选取结构参数. 该结构采用nMOS栅下的含p+埋沟的衬底体电阻代替传统6管CMOS SRAM单元中的pMOS元件，具有面积小、工艺简单的优点. 该结构可以在0.5V的电源电压下正常工作，与6管单元相比，该单元瞬态响应正常，功耗只有6管单元的1/10，满足低压低功耗的要求.     

一种低压低功耗SRAM/SOI单元设计

提出一种改进4管自体偏压结构SRAM/SOI单元.基于TSUPREM4和MEDICI软件的模拟和结构性能的分析,设计单元结构并选取结构参数.该结构采用nMOS栅下的含p 埋沟的衬底体电阻代替传统6管CMOSSRAM单元中的pMOS元件,具有面积小、工艺简单的优点.该结构可以在0.5V的电源电压下正常工作,与6管单元相比,该单元瞬态响应正常,功耗只有6管单元的1/10,满足低压低功耗的要求.     

一种低压低功耗SRAM/SOI单元设计

提出一种改进4管自体偏压结构SRAM/SOI单元.基于TSUPREM4和MEDICI软件的模拟和结构性能的分析,设计单元结构并选取结构参数.该结构采用nMOS栅下的含p+埋沟的衬底体电阻代替传统6管CMOSSRAM单元中的pMOS元件,具有面积小、工艺简单的优点.该结构可以在0.5V的电源电压下正常工作,与6管单元相比,该单元瞬态响应正常,功耗只有6管单元的1/10,满足低压低功耗的要求.     

一种面向可容错应用的低功耗SRAM架构

提出了一种面向可容错应用的低功耗SRAM架构。通过对输入数据进行预编码,提出的SRAM架构实现了以较小的精度损失降低SRAM电路功耗。设计了一种单端的8管SRAM单元。该8管单元采用读缓冲结构,提升了读稳定性。采用打破反馈环技术,提升了写能力。以该8管单元作为存储单元的近似SRAM电路能够在超低压下稳定工作。在40 nm CMOS工艺下对电路进行仿真。结果表明,该8管单元具有良好的稳定性和极低的功耗。因此,以该8管单元作为存储单元的近似SRAM电路具有非常低的功耗。在0.5 V电源电压和相同工作频率下,该近似SRAM电路的功耗比采用传统6管单元的SRAM电路功耗降低了59.86%。     

一种提高SRAM写能力的自适应负位线电路设计

随着器件尺寸缩小到纳米级,在SRAM生产过程中,工艺偏差变大会导致SRAM单元写能力变差.针对这一问题,提出了一种新型负位线电路,可以提高SRAM单元的写能力,并通过控制时序和下拉管的栅极电压达到自我调节负位线电压,使负电压被控制在一定范围内.本设计采用TSMC 40nm工艺模型对设计的电路进行仿真验证,结果证明,设计的电路可以改善写能力,使SRAM在电压降到0.66V的时候仍能正常工作,并且和传统设计相比,本电路产生的负电压被控制在一个范围内,有利于提高晶体管的使用寿命,改善良率,节省功耗.     

PDSOI nMOSFETs关态击穿特性

分别采用不同的背栅沟道注入剂量制成了部分耗尽绝缘体上硅浮体和H型栅体接触n型沟道器件.对这些器件的关态击穿特性进行了研究.当背栅沟道注入剂量从1.0×1013增加到1.3×1013cm-2,浮体n型沟道器件关态击穿电压由5.2升高到6.7V,而H型栅体接触n型沟道器件关态击穿电压从11.9降低到9V.通过测量寄生双极晶体管静态增益和漏体pn结击穿电压,对部分耗尽绝缘体上硅浮体和H型栅体接触n型沟道器件的击穿特性进行了定性解释和分析.     

低功耗容软错误的65 nm CMOS 12管SRAM单元

提出了一种具有软错误自恢复能力的12管SRAM单元。该单元省去了专用的存取管,具有高鲁棒性、低功耗的优点。在65 nm CMOS工艺下,该结构能够完全容忍单点翻转,容忍双点翻转的比例是64.29%,与DICE加固单元相比,双点翻转率降低了30.96%。与DICE、Quatro等相关SRAM加固单元相比,该SRAM单元的读操作电流平均下降了77.91%,动态功耗平均下降了60.21%,静态电流平均下降了44.60%,亚阈值泄漏电流平均下降了27.49%,适用于低功耗场合。     

PDSOI nMOSFETs关态击穿特性

分别采用不同的背栅沟道注入剂量制成了部分耗尽绝缘体上硅浮体和H型栅体接触n型沟道器件.对这些器件的关态击穿特性进行了研究.当背栅沟道注入剂量从1.0×1013增加到1.3×1013cm-2,浮体n型沟道器件关态击穿电压由5.2升高到6.7V,而H型栅体接触n型沟道器件关态击穿电压从11.9降低到9V.通过测量寄生双极晶体管静态增益和漏体pn结击穿电压,对部分耗尽绝缘体上硅浮体和H型栅体接触n型沟道器件的击穿特性进行了定性解释和分析.     

一种基于位交错结构的亚阈值10管SRAM单元

提出了一种基于位交错结构的亚阈值10管SRAM单元,实现了电路在超低电压下能稳定地工作,并降低了电路功耗。采用内在读辅助技术消除了读干扰问题,有效提高了低压下的读稳定性。采用削弱单元反馈环路的写辅助技术,极大提高了写能力。该10管SRAM单元可消除半选干扰问题,提高位交错结构的抗软错误能力。在40 nm CMOS工艺下对电路进行了仿真。结果表明,该10管SRAM单元在低压下具有较高的读稳定性和优异的写能力。在0.4 V工作电压下,该10管SRAM单元的写裕度为传统6管单元的14.55倍。     

一种新式SEU加固PD SOI SRAM单元

本文提出了一种新式SEU加固的10管PD SOI静态存储单元。通过将互锁反相器中的上拉和下拉管分割成两个串联的晶体管,该单元可有效抑制PD SOI晶体管中的寄生BJT和源漏穿通电荷收集效应,这两种电荷收集效应是引起PD SOISRAM翻转的主要原因。通过混合仿真发现,与穿通的浮体6T单元相比,该单元可完全解决粒子入射单个晶体管引起的单粒子翻转。通过分析该新式单元的翻转机制,认为其SEU性能近似与6T SOI SRAM的单粒子多位翻转性能相等。根据参考文献的测试数据,粗略估计该新式单元的SEU性能比普通45nm 6T SOI SRAM单元提升了17倍。由于新增加了四个晶体管,该单元在面积上增加了43.4%的开销,性能方面有所降低。     

Highly stable,low power FinFET SRAM cells with exploiting dynamic back-gate biasing

In this paper, we propose two independent gate (IG) FinFET SRAM cells that use PMOS access transistors and back-gate (BG) biasing to achieve a high-stability performance. In the first cell, the back-gate of the access transistors is connected to the adjacent storage nodes, and the back-gate of the pull-down transistors is dynamically biased. Simulations indicate that the first proposed cell offers higher read static noise-margin (SNM), higher write-ability, least static/dynamic power, and a comparable read current compared to the previous IG-6TSRAMs. The second cell is a novel independently-controlled-gate FinFET SRAM cell, which provides a high read stability, the highest write-ability, low static power dissipation and high read current compared to the previously reported independently-controlled-gate FinFET SchmitTrigger based SRAM cells. This cell supportsbit-interleaving property at V_DD = 0.4 V with high read/write yields.     

An Ultra-Low-Power 9T SRAM Cell Based on Threshold Voltage Techniques

This paper presents a new nine-transistor (9T) SRAM cell operating in the subthreshold region. In the proposed 9T SRAM cell, a suitable read operation is provided by suppressing the drain-induced barrier lowering effect and controlling the body–source voltage dynamically. Proper usage of low-threshold voltage (L-\(V_{\mathrm{t}}\)) transistors in the proposed design helps to reduce the read access time and enhance the reliability in the subthreshold region. In the proposed cell, a common bit-line is used in the read and write operations. This design leads to a larger write margin without using extra circuits. The simulation results at 90 nm CMOS technology demonstrate a qualified performance of the proposed SRAM cell in terms of power dissipation, power–delay product, write margin, read access time and sensitivity to process, voltage and temperature variations as compared to the other most efficient low-voltage SRAM cells previously presented in the literature.     

A novel high reliability CMOS SRAM cell

A novel 8T single-event-upset(SEU) hardened and high static noise margin(SNM) SRAM cell is proposed. By adding one transistor paralleled with each access transistor,the drive capability of pull-up PMOS is greater than that of the conventional cell and the read access transistors are weaker than that of the conventional cell.So the hold,read SNM and critical charge increase greatly.The simulation results show that the critical charge is almost three times larger than that of the conventional 6T cell by appropriately sizing the pull-up transistors.The hold and read SNM of the new cell increase by 72%and 141.7%,respectively,compared to the 6T design,but it has a 54%area overhead and read performance penalty.According to these features,this novel cell suits high reliability applications,such as aerospace and military.     

A 500-MHz DDR High-Performance 72-Mb 3-D SRAM Fabricated With Laser-Induced Epitaxial c-Si Growth Technology for a Stand-Alone and Embedded Memory Application

For the first time, the smallest 3-D stacked six-transistor (6T) static-random-access-memory (SRAM) cell technology is successfully developed by using a laser crystallization process to grow perfect single-crystal Si layers on the amorphous dielectric Si dioxide layers. The SRAM cell size is $ hbox{36} hbox{F}^{2}$ and 0.36 $muhbox{m}^{2}$ with 100-nm complementary MOS technology. The 3-D SRAM cell consists of three differently layered and 3-D stacked-cell thin-film transistors (TFTs), whose channel area is a perfect single-crystal Si. The electrical characteristics of the pass n-channel MOS TFT and the load p-channel MOS TFT are very close to those of the planar bulk transistors because their channel Si layers are perfect single-crystal films. A 500-MHz high-performance and highly cost effective 72-Mb-density 3-D SRAM, which is comparable to the conventional planar 6T SRAM in electrical performance, was successfully fabricated for a stand-alone and embedded memory, with this 3-D stacked 6T SRAM cell technology, the low-temperature TFT formation process, periphery-only Co salicidation, and the W shunt wordline scheme.      

一种新颖的高可靠CMOS SRAM 单元

本文提出了一种新颖的8管抗SUE,高噪声容限的SRAM单元。通过在每个访问晶体管上增加了一个并联的晶体管,上拉PMOS的驱动能力可以设计的比传统单元的PMOS的驱动能力更强,读访问晶体管可以设计得比传统单元的读访问晶体管更弱。因此保持,读噪声容限和临界电荷都有较大提高。仿真结果表明,与传统的6管单元相比,合理设计上拉晶体管尺寸后,临界电荷提高了将近3倍。保持和读静态噪声容限分别提高了72%和141.7%。但该新式单元的面积额外开销为54%,读性能也有所下降,适用于高可靠性应用,如航天,军事等。     

Relaxing Conflict Between Read Stability and Writability in 6T SRAM Cell Using Asymmetric Transistors

We propose an asymmetric-MOSFET-based sixtransistor (6T) SRAM cell to alleviate the conflicting requirements of read and write operations. The source-to-drain and drain-to-source characteristics of access transistors are optimized to improve writability without sacrificing read stability. The proposed technique improves the writability by 9%–11%, with iso read stability being compared with a conventional 6T SRAM cell based on symmetric-MOSFET access transistors in 45-nm technology.      

Novel SEU hardened PD SOI SRAM cell

A novel SEU hardened 10T PD SOI SRAM cell is proposed.By dividing each pull-up and pull-down transistor in the cross-coupled inverters into two cascaded transistors,this cell suppresses the parasitic BJT and source-drain penetration charge collection effect in PD SOI transistor which causes the SEU in PD SOI SRAM. Mixed-mode simulation shows that this novel cell completely solves the SEU,where the ion affects the single transistor.Through analysis of the upset mechanism of this novel cell,SEU performance is roughly equal to the multiple-cell upset performance of a normal 6T SOI SRAM and it is thought that the SEU performance is 17 times greater than traditional 6T SRAM in 45nm PD SOI technology node based on the tested data of the references.To achieve this,the new cell adds four transistors and has a 43.4%area overhead and performance penalty.     

Single-Ended Boost-Less (SE-BL) 7T Process Tolerant SRAM Design in Sub-threshold Regime for Ultra-Low-Power Applications

A novel single-ended boost-less 7T static random access memory cell with high write-ability and reduced read failure is proposed. Proposed 7T cell utilizes dynamic feedback cutting during write/read operation. The 7T also uses dynamic read decoupling during read operation to reduce the read disturb. Proposed 7T writes “1” through one NMOS and writes “0” using two NMOS pass transistors. The 7T has mean \((\mu )\) of 222.3 mV (74.1 % of supply voltage) for write trip point where 5T fails to write “1” at 300 mV. It gives mean \((\mu )\) of 276 mV (92 % of supply voltage) for read margin, while 5T fails due to read disturb at 300 mV. The hold static noise margin of 7T is maintained close to that of 5T. The read operation of 7T is 22.5 % faster than 5T and saves 10.8 % read power consumption. It saves 36.9 % read and 50 % write power consumption as compared to conventional 6T. The novel design of proposed 7T consumes least read power and achieves the lowest standard deviation as compared to other reported SRAM cells. The power consumption of 1 kb 7T SRAM array during read and write operations is 0.70\(\times \) and 0.65\(\times \), respectively, of 1 kb 6T array. The techniques used by the proposed 7T SRAM cell allow it to operate at ultra-low-voltage supply without any write assist in UMC 90 nm technology node. Future applications of the proposed 7T cell can potentially be in low-voltage, ultra-low-voltage and medium-frequency operations like neural signal processor, sub-threshold processor, wide-operating-range IA-32 processor, FFT core and low-voltage cache operation.