CMOS器件60Co γ射线、电子和质子电离辐射损伤比较

利用TRIM95蒙特卡罗软件计算了质子在二氧化硅中的质量阻止本领和能量沉积，比较了质子在二氧化硅中的电离阻止本领与核阻止本领，分析了质子在材料的表面吸收剂量与灵敏区实际吸收剂量的关系.利用⁶⁰Co γ射线、1MeV电子和2—9 MeV质子对CC4007RH和CC4011器件进行辐照实验，比较⁶⁰Co γ射线和带电粒子的电离辐射损伤情况.实验结果表明，⁶⁰Co γ射线、1MeV 电子和2—7MeV质子辐照损伤效应中，在0V栅压下可以相互等效； 关键词： γ射线 电子 质子 辐射损伤     

65 nm互补金属氧化物半导体场效应和晶体管总剂量效应及损伤机制

对65 nm互补金属氧化物半导体工艺下不同尺寸的N型和P型金属氧化物半导体场效应晶体管(NMOSFET和PMOSFET)开展了不同偏置条件下电离总剂量辐照实验.结果表明:PMOSFET的电离辐射响应与器件结构和偏置条件均有很强的依赖性,而NMOSFET表现出较强的抗总剂量性能;在累积相同总剂量时,PMOSFET的辐照损伤远大于NMOSFET.结合理论分析和数值模拟给出了PMOSFET的辐射敏感位置及辐射损伤的物理机制.     

超深亚微米互补金属氧化物半导体器件的剂量率效应

对0.18 μm互补金属氧化物半导体(CMOS)工艺的N型金属氧化物半导体场效应晶体管(NMOSFET)及静态随机存储器(SRAM)开展了不同剂量率下的电离总剂量辐照试验研究. 结果表明: 在相同累积剂量, SRAM的低剂量率辐照损伤要略大于高剂量率辐照的损伤, 并且低剂量率辐照损伤要远大于高剂量率辐照加与低剂量率辐照时间相同的室温退火后的损伤. 虽然NMOSFET 低剂量率辐照损伤略小于高剂量率辐照损伤, 但室温退火后, 高剂量率辐照损伤同样要远小于低剂量率辐照损伤. 研究结果表明0.18 μm CMOS工艺器件的辐射损伤不是时间相关效应. 利用数值模拟的方法提出了解释CMOS器件剂量率效应的理论模型.     

双极线性稳压器电离辐射剂量率效应及其损伤分析

为了对双极线性稳压器在电离辐射环境下损伤变化特征及其剂量率效应进行研究,选择一组器件进行⁶⁰Co γ高低剂量率的辐照和退火试验. 结果表明线性稳压器的输出电压、最大负载电流、线性调整率、压降电压等多个关键参数都有不同程度的蜕变. 且各器件在高低剂量率下的辐照响应略有不同,表现出不同的剂量率效应. 文中通过多种形式的测试结果分析,系统地讨论了各参数变化的原因及其内部各模块对稳压器功能的影响. 结合电离损伤退火特性,探讨了各剂量率效应形成的原因. 这不但对工程应用考核提供了参考,而且为设 关键词： 双极线性稳压器 总剂量效应 剂量率效应 辐射损伤     

不同发射极面积npn晶体管高低剂量率辐射损伤特性

影响npn晶体管辐射损伤的因素有很多,如晶体管工艺、剂量率以及辐照偏置等.主要研究了三种发射极面积的国产npn晶体管在高低剂量率下的辐射损伤特性,分析了发射极尺寸对辐射损伤的影响.研究结果表明,国产npn晶体管具有低剂量率损伤增强效应,且发现当小电流注入下晶体管的辐射损伤会表现得愈加显著.比较三种发射极尺寸的晶体管辐照响应发现,发射极周长面积比P/A越大时晶体管归一化过剩基极电流ΔI_B/I_B0也越大.详细阐述了npn晶体管辐射损伤机制,从发射极尺寸和晶体管工作电压角度对npn晶体管的加固保证方法进行了探索. 关键词： 发射极面积 国产npn晶体管 剂量率 辐射损伤     

不同剂量率下锗硅异质结双极晶体管电离损伤效应研究

对于相同制作工艺的NPN锗硅异质结双极晶体管(SiGe HBT), 在不同辐照剂量率下进行⁶⁰Co γ射线的辐照效应与退火特性的研究. 测量结果表明, 两种辐照剂量率下, 随着辐照总剂量增加, 晶体管基极电流增大, 共发射极电流放大倍数降低, 且器件的辐照损伤、性能退化与辐照剂量率相关, 低剂量率下辐照损伤较高剂量率严重. 在经过与低剂量率辐照等时的退火后, 高剂量率下的辐照损伤仍较低剂量率下的损伤低, 即待测SiGeHBT具有明显的低剂量率损伤增强效应(ELDRS). 本文对相关的物理机理进行了探讨分析. 关键词： 锗硅异质结双极晶体管 低剂量率辐照损伤增强 辐照效应     

氢气浸泡辐照加速方法在3DG111器件上的应用及辐射损伤机理分析

本文以~(60)Co为辐照源,针对3DG111型晶体管,利用半导体参数分析仪和深能级缺陷瞬态谱仪,研究高/低剂量率和有/无氢气浸泡条件下,电性能和深能级缺陷的演化规律.试验结果表明,与高剂量率辐照相比,低剂量率辐照条件下,3DG111型晶体管的电流增益退化更加严重,这说明该器件出现了明显的低剂量率增强效应;无论是高剂量率还是低剂量率辐照条件下,3DG111晶体管的辐射损伤缺陷均是氧化物正电荷和界面态陷阱,并且低剂量率条件下,缺陷能级较深;氢气浸泡后在高剂量率辐照条件下,与未进行氢气处理的器件相比,辐射损伤程度明显加剧,且与低剂量率辐照条件下器件的损伤程度相同,缺陷数量、种类及能级也相同.因此,氢气浸泡处理可以作为低剂量率辐射损伤增强效应加速评估方法的有效手段.     

高$lt;i$gt;k$lt;/i$gt;栅介质小尺寸全耗尽绝缘体上锗p型金属氧化物半导体场效应晶体管漏源电流模型

通过求解沟道的二维泊松方程得到沟道表面势和沟道反型层电荷, 建立了高k栅介质小尺寸绝缘体上锗(GeOI) p型金属氧化物半导体场效应晶体管(PMOSFET)的漏源电流解析模型. 模型包括了速度饱和效应、迁移率调制效应和沟长调制效应, 同时考虑了栅氧化层和埋氧层与沟道界面处的界面陷阱电荷、氧化层固定电荷对漏源电流的影响. 在饱和区和非饱和区, 漏源电流模拟结果与实验数据符合得较好, 证实了模型的正确性和实用性. 利用建立的漏源电流模型模拟分析了器件主要结构和物理参数对跨导、漏导、截止频率和电压增益的影响, 对GeOI PMOSFET的设计具有一定的指导作用. 关键词： 绝缘体上锗p型金属氧化物半导体场效应晶体管 漏源电流模型 跨导 截止频率     

$lt;i$gt;γ$lt;/i$gt;射线总剂量辐照效应对应变Sip型金属氧化物半导体场效应晶体管阈值电压与跨导的影响研究

分析了双轴应变Si p型金属氧化物半导体场效应晶体管(PMOSFET)在γ射线辐照下载流子的微观输运过程, 揭示了γ射线的作用机理及器件电学特性随辐照总剂量的演化规律, 建立了总剂量辐照条件下的双轴应变Si PMOSFET 阈值电压与跨导等电学特性模型, 并对其进行了模拟仿真. 由仿真结果可知, 阈值电压的绝对值会随着辐照总剂量的积累而增加, 辐照总剂量较低时阈值电压的变化与总剂量基本呈线性关系, 高剂量时趋于饱和; 辐照产生的陷阱电荷增加了沟道区载流子之间的碰撞概率, 导致了沟道载流子迁移率的退化以及跨导的降低. 在此基础上, 进行实验验证, 测试结果表明实验数据与仿真结果基本相符, 为双轴应变Si PMOSFET辐照可靠性的研究和应变集成电路的应用与推广提供了理论依据和实践基础. 关键词： 应变Sip型金属氧化物半导体场效应晶体管 总剂量辐照 阈值电压 跨导     

静态存储器型现场可编程门阵列总剂量辐射损伤效应研究

本文从FPGA器件内部最基本的CMOS单元出发,分析了器件功能失效时反相器输出波形随累积剂量的变化关系,进而研究Altera SRAM型FPGA器件⁶⁰Co γ射线辐照后的总剂量辐射损伤效应.实验结果表明:由于场氧漏电和结构漏电的影响,随着累积剂量的增加输出波形发生畸变,峰峰值变为原来的十分之一左右,但输出波形还有相对的高低电平;同时,输出高电平不能保持原有的状态,迅速地向低电平转换,并且转换速度随着累积剂量的增加而加快,输出低电平相对初始值有一定程度抬高;由于栅氧厚度变薄,输出波形 关键词： 60Coγ')" href="#">⁶⁰Coγ 总剂量辐射损伤效应 SRAM型FPGA CMOS单元     

Some studies of BF2 and B+F implanted Silicon

Ion-implanted shallow junctions have been investigated using BE₂ (molecular ions) by the anodic oxidation method coupled with a four-point probe technique. BF₂ ions were implanted through screen oxide at doses of 3–5 × 10¹⁵ ions/cm² and energies of 25 and 45 keV which is equivalent to 5.6 keV and 10 keV of boron ions. The effect of energy, dose and annealing temperature on shallow junctions is presented in this paper. The shallow junctions in the range of 0.19 μm to 0.47 μm were fabricated.

The effect of fluorine on sheet resistivity of boron implanted silicon at various doses, treated with two-step and three-step annealing, is also presented for comparison in the paper.     

双极电压比较器电离辐射损伤及剂量率效应分析

为了对双极电压比较器在电离辐射环境下的损伤变化特征及其剂量率效应进行研究,选择一组器件,在不同偏置条件下进行60Coγ高低剂量率的辐照和退火试验.结果表明:电压比较器的电源电流、偏置电流及失调电压等多个关键参数都有不同程度的蜕变;偏置条件对于电压比较器的辐射响应有很大影响;此外,不同公司生产的同种型号电路表现出不同的剂量率效应;通过对测试结果分析,系统地讨论了各参数变化的原因,并结合电离损伤退火特性,探讨了各剂量率效应形成的机理.研究结果对工程应用考核提供了参考,而且为设计抗辐射加固器件提供了依据.     

典型模拟电路低剂量率辐照损伤增强效应的研究与评估

采用变剂量率和变温两种辐照方法,对4款典型模拟电路的低剂量率辐照损伤特性及变化规律进行了研究与评估,分析了两种辐照方法下其辐照敏感参数的变化,比较了不同辐照方式下器件的退化程度,讨论了这两种实验室加速评估低剂量率辐照损伤方法的机理.结果显示,变剂量率辐照可以较快地预测实际低剂量率下的辐照损伤趋势,且在较低的总剂量下能够给出不太保守的估计,但其预测的总剂量受到器件退化速度的影响;变温辐照加速评估方法能够保守地估计其低剂量率下的辐照损伤,其评估范围不仅可达1000 Gy(Si),且可将评估时间缩短为12 h左右.研究结果表明,双极电路的低剂量率辐照损伤增强效应与感生的界面态密度和氢化的氧空位缺陷有关,辐照时剂量率和温度的改变会促进界面态的生长,抑制界面态的钝化作用,从而激发器件的辐照损伤潜能.     

双极器件ELDRS效应研究进展

电离总剂量是航天电子系统辐射效应研究的重要问题,其中双极器件因其特有的低剂量率损伤增强（Enhanced low Dose Rate Sensitivity,ELDRS）效应,已成为航天用双极器件抗电离总剂量效应发展重点突破的方向及难点问题。本文综述了ELDRS效应及低剂量率加速评估技术的研究进展,并结合ELDRS效应难点问题,给出了最新关于ELDRS效应的研究结果。试验结果表明,采用变温辐照方法不仅可以保守地用于双极器件在0~200 krad （Si）范围的ELDRS效应评估,将评估时间从7.7个月缩短至11 h,还可将其应用于双极模拟电路总剂量和单粒子协同效应的评估,同样可以获得保守且快速的评估效果。     

Total ionizing dose effects of domestic Si Ge HBTs under different dose rates

The total ionizing radiation(TID) response of commercial NPN silicon germanium hetero-junction bipolar transistors(Si Ge HBTs) produced domestically are investigated under dose rates of 800 m Gy(Si)/s and 1.3 m Gy(Si)/s with a Co-60 gamma irradiation source. The changes of transistor parameters such as Gummel characteristics, and excess base current before and after irradiation, are examined. The results of the experiments show that for the KT1151, the radiation damage is slightly different under the different dose rates after prolonged annealing, and shows a time dependent effect(TDE). For the KT9041, however, the degradations of low dose rate irradiation is higher than for the high dose rate, demonstrating that there is a potential enhanced low dose rate sensitivity(ELDRS) effect for the KT9041. The possible underlying physical mechanisms of the different dose rates responses induced by the gamma rays are discussed.     

Fluorescence properties of divalent and trivalent europium ions in CdWO4 single crystals grown by Bridgman method

Optical absorption, excitation, and fluorescence were investigated in Eu ion-doped CdWO₄ single crystal grown by a modified Bridgman method. The results indicate that Eu²⁺ and Eu³⁺ ions coexist in CdWO₄ crystal and an energy transfer occurs between these Eu²⁺ and Eu³⁺ ions. When the crystal is excited by 266-nm light, the energy corresponding to the 4f⁶5d to ⁸S_7/2 transition of Eu²⁺ ions results in the excitation of the Eu³⁺ ions to the ⁵D_J level. The effect on fluorescence of annealing in oxygen at various temperatures was investigated. The excitation intensity of Eu²⁺ ions at 266 nm decreases as annealing temperature increases from 300 K to 1073 K, but it remains at a certain equilibrium level when the annealing temperature is further increased.     

Behavior of antimony above solid solubility in silicon produced by implantation and laser annealing

Abstract

Antimony implantation into <111> silicon was carried out at RT with a dose of 4.5 × 10¹⁵ cm^?2, energy 75 keV. For the annealing of the sample pulses of a Q-switched ruby laser were used with energy density of ～ 1.5 Joule/cm² and duration of 15–20 nsec. Hall effect measurement was applied to determine the electrical activity of the layers. Lattice location and the depth profile of Sb was studied by RBS and channeling technique. Measurements show that after laser annealing Sb occupies mostly substitutional sites in Si with 84% electrical activity. It has been shown that after laser annealing the concentration of Sb in lattice sites is almost an order of magnitude higher than the limit of solid solubility. Isochron and isothermal annealing of these samples up to 1150°C was carried out to study the kinetics of reverse annealing of antimony.     

Radiation effects on luminescent and structural properties of YPO4: Pr3+ nanophosphors

ABSTRACT

YPO₄ phosphors doped with trivalent ion Pr³⁺ were prepared by sol–gel method and treated with different doses of gamma radiation, from 0.25 MGy to 4 MGy. Effects of radiation on morphology, structure and luminescent properties were analyzed. Also, the influence of radiation on the change in the color of the samples was examined. The color efficiency of powders was evaluated by colorimetric analysis (CIE and L * a * b system). It has been observed that powders change color under the influence of radiation, i.e. they pass from white to pinkish red. Also, it has been determined that the radiation affects morphology change, as the particle size increases with increasing of the radiation dose. With the increase in the radiation dose, the emission intensity of samples decreases. The structure remains almost unchanged after irradiation, and the intensity constantly decreases with increasing of dose.     

Radiation-induced swelling and amorphization in Ca2Nd8(SiO4)6O2

Specimens of Ca₂Nd₈(SiO₄)₆O₂ were doped with 1.2 wt% ²⁴⁴Cm and the effects of self-radiation damage from alpha decay were determined as a function of cumulative dose. The macroscopic volume of the specimens increased exponentially with dose to a limiting (saturation) value of ～8.0%. The initially crystalline material became completely X-ray amorphous at a dose of 11.7 × 10²⁴ alpha decays/m³. The dissolution rate of the amorphous state was about an order of magnitude higher than the crystalline state. The stored energy of the amorphous state was ～130 J/g. Differential thermal analysis along with isochronal and isothermal-step annealing were used to study the kinetics associated with the thermal recovery of the radiation-induced swelling and amorphization. A single recovery stage associated with recrystallization of the amorphous material was observed and the activation energy was determined to be 3.1±0.2 eV.