Total ionizing radiation effects of 2-T SONOS for 130 nm/4 Mb NOR flash memory technology  

作　　者：QIAO FengYing PAN LiYang YU Xiao MA HaoZhi WU Dong XU Jun 

机构地区：[1]Institute of Microelectronics,Tsinghua University [2]Tsinghua National Laboratory for Information Science and Technology

出　　处：《Science China(Information Sciences)》2014年第6期169-177,共9页中国科学（信息科学）（英文版）

基　　金：supported by National Basic Research Program of China(Grant No.2011CBA00602);National Natural Science Foundation of China(Grant Nos.61106102,61176033)

摘　　要：In this paper,we have studied the total ionizing dose（TID）radiation response up to 2 Mrad（Si）of silicon-oxide-nitride-oxide-silicon（SONOS）memory cells and memory circuits,fabricated in a 130 nm complimentary metal-oxide-semiconductor（CMOS）SONOS technology.We explored the threshold voltage（VT）degradation mechanism and found that the VT shifts of SONOS cells depend on the charge state;simply programming the cell to a higher VT cannot compensate for the radiation induced VT loss.The off-state current（Ioff）increase in the SONOS cell is also studied in this paper.Both VT and Ioffdegradation would affect the memory system.Read data failures are mainly caused by VT shifts under irradiation,and program and erase failures are mainly caused by increased Ioff,which overloads the charge pumping circuit.By varying the reference current,our 4 Mb NOR flash chip has the potential to survive a radiation dose of 1 Mrad（Si）in read mode.In this paper,we have studied the total ionizing dose（TID）radiation response up to 2 Mrad（Si）of silicon-oxide-nitride-oxide-silicon（SONOS）memory cells and memory circuits,fabricated in a 130 nm complimentary metal-oxide-semiconductor（CMOS）SONOS technology.We explored the threshold voltage（VT）degradation mechanism and found that the VT shifts of SONOS cells depend on the charge state;simply programming the cell to a higher VT cannot compensate for the radiation induced VT loss.The off-state current（Ioff）increase in the SONOS cell is also studied in this paper.Both VT and Ioffdegradation would affect the memory system.Read data failures are mainly caused by VT shifts under irradiation,and program and erase failures are mainly caused by increased Ioff,which overloads the charge pumping circuit.By varying the reference current,our 4 Mb NOR flash chip has the potential to survive a radiation dose of 1 Mrad（Si）in read mode.

关 键 词：silicon-oxide-nitride-oxide-silicon SONOS total ionizing dose TID flash memory radiation effects 130 nm 

分 类 号：TP333[自动化与计算机技术—计算机系统结构] TN722.77[自动化与计算机技术—计算机科学与技术]