γ射线总剂量辐照对单轴应变Si纳米n型金属氧化物半导体场效应晶体管栅隧穿电流的影响  

Influence of γ-ray total dose radiation effect on the tunneling gate current of the uniaxial strained Si nanometer n-channel metal-oxide-semiconductor field-effect transistor

作　　者：郝敏如 胡辉勇[1] 廖晨光 王斌[1] 赵小红[1] 康海燕[1] 苏汉[1] 张鹤鸣[1] 

机构地区：[1]西安电子科技大学微电子学院宽禁带半导体材料与器件重点实验室,西安710071

出　　处：《物理学报》2017年第7期361-369,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61474085);陕西省科技计划项目(批准号:2016GY-085)资助的课题~~

摘　　要：基于γ射线辐照条件下单轴应变Si纳米n型金属氧化物半导体场效应晶体管(NMOSFET)载流子的微观输运机制,揭示了单轴应变Si纳米NMOSFET器件电学特性随总剂量辐照的变化规律,同时基于量子机制建立了小尺寸单轴应变Si NMOSFET在γ射线辐照条件下的栅隧穿电流模型,应用Matlab对该模型进行了数值模拟仿真,探究了总剂量、器件几何结构参数、材料物理参数等对栅隧穿电流的影响.此外,通过实验进行对比,该模型仿真结果和总剂量辐照实验测试结果基本符合,从而验证了模型的可行性.本文所建模型为研究纳米级单轴应变Si NMOSFET应变集成器件可靠性及电路的应用提供了有价值的理论指导与实践基础.The carrier microscopic transport process of uniaxial strained Si n-channel metal-oxide-semiconduct or field-effect transistor（NMOSFET） is analyzed under γ-ray radiation.The model of radiation-induced defect densities that are quantitative representations of trapped charges integrated across the thickness of the oxide（N_（ot））,and the number of interface traps at the semiconductor/oxide interface（N_（it））,is established.The variations of electrical characteristics of the uniaxial strained Si nanometer NMOSFET are also investigated under the total dose radiation.The device of uniaxial strained Si nanometer NMOSTET is irradiated by a ^（60）Co γ-ray laboratory source at a constant dose rate of 0.5 Gy（Si）/s.The TID is deposited in several steps up to a maximum value of 2.5 kGy.Electrical measurements are performed at each TID step.All irradiated samples are measured using field test,and are required to finish measurement within30 min,in order to reduce the annealing effect.Static drain-current I_D vs.gate-voltage V_（GS） electrical characteristics are measured with an HP4155 B parametric analyzer.Some parameter extractions presented here come from these static measurements including the threshold voltage V_（TH）,the trans-conductance g_m,and the leakage current I_（OFF）（I_D at V_（GS）=0 V and V_（DS）=V_（DD））.Irradiation bias：V_G =＋1 V,drain voltage V_D is equal to source voltage V_S（V_D=V_S=0）.Measurement bias：V_G=0-1V,scanning voltage V_（step）=0.05 V,=50 mV,and V_S=0.The results indicate the drift of threshold voltage,the degradation of carrier mobility and the increase of leakage current because of the total dose radiation.Based on quantum mechanics,an analytical model of tunneling gate current of the uniaxial strained Si nanometer is developed due to the total dose irradiation effect.Based on this model,numerical simulation is carried out by Matlab.The influences of total dose,geometry and physics parameters on tunneling gate current are simulated.The

关 键 词：单轴应变Si 纳米n型金属氧化物半导体场效应晶体管 总剂量 栅隧穿电流 

分 类 号：TN386[电子电信—物理电子学]