Generation of Oxide Charge and Interface States by Ionizing Radiation and by Tunnel Injection Experiments

Results of irradiation and high field tunnel injection experiments on MOS capacitors are discussed. The midgap voltage shift as a function of dose is caused by hole trapping only. In the case of tunnel injection, the generation of electron-hole pairs by impact ionization requires a much larger electron density and high fields. Thus a model of charge build-up is established which takes into account the hole trapping in neutral oxide states, the subsequent electron trapping in now positively charged states and detrapping of captured electrons. By means of this model, the prediction of the radiation hardness of MOS devices is feasible, provided that the impact ionization coefficient a is known accurately. If this is not the case, the combined techniques of ionizing irradiation and tunnel injection can be utilized to determine ? = ?o exp(-H?/F) as a function of the electrical field F. Electron capture and detrapping crosssections ?n and ?n, resp., can be deduced by fitting the model to the experimental results. An F-3 dependency for ?n and an exp(-H?/F) dependency for ?n are found. Only a weak dependence on different processing parameters is observed. The proposed model is verified by a sequence of irradiation and injection steps. The generation of oxide charge is accompanied by an increase in interface state density Dit with a distribution, which peaks at about 0.15 eV above midgap, in both experiments. The results indicate that the generation of interface states is proportional to the amount of trapped holes.     

ONO反熔丝结构的电离辐照性能研究

描述了ONO反熔丝的物理结构,采用ONO薄膜传导模型分析了ONO反熔丝结构在受到电离辐照时,其内部电子-空穴的运动规律。分别对ONO反熔丝FPGA A1460A和A40MX04进行了电离辐照实验,测试了电流与辐照剂量的关系以及FPGA功能失效阈值。理论分析和实验数据说明了该结构比单层SiO2具有更好的抗电离辐照性能。     

不同类型电离辐射对聚醚聚氨酯材料的辐射效应

文章讨论聚醚聚氨酯材料经γ射线和电子束两种电离辐射辐照后的辐射效应。采用气相色谱、差示扫描量热分析和电子自旋共振技术，研究材料经不同类型电离辐射辐照后材料的热性能和自由基强度的变化及其辐解气体产物的种类和G值。结果表明，γ射线和电子束辐照聚醚聚氨酯材料时，二者对材料的作用机理虽相同，但能量淀积方式却不同，导致自由基数量和强度有所不同，同时材料的热性能和辐解气体小分子也存在差异。     

CCD电离辐射加固工艺研究

本文以简单的MOS电容为手段,研究CCD工艺,以提高器件的抗电离辐射能力。研究发现,栅氧化温度、SiO_2栅介质厚度和CCD工艺中栅氧化以后的高温过程对辐照性能的影响最大;并提出减薄SiO_2栅介质厚度、在1000℃干氧栅氧化、表面栅和埋栅下SiO_2介质在相同条件下生长以及栅氧化后工艺流程中的高温步骤的温度不能超过栅氧化温度和尽量减少栅氧化后的高温步骤等改进的工艺措施。     

电离辐射诱发的基因组不稳定性和旁效应

近10年来,对于基因组不稳定性和旁效应的研究已成为生物学和放射生物学领域的一个热点。随着对辐射损伤研究的深入,电离辐射引起的非靶效应（如基因组不稳定性、旁效应等）将对与辐射照射有关的危险评价提出新的挑战。本文就体内、外电离辐射诱发的基因组不稳定性,体内、外旁效应以及二者之间的关系做一简要概述。     

医用电离辐射中的防护与安全

IRPA-1 0大会就医用电离辐射中的防护与安全领域提供了 4次特别讲座、2次专题会议和 70余篇壁报展示。本文对这个领域的论文进行评论 ,共由两部分组成 :第 1部分叙述特别讲座中 4个报告的内容 ;第 2部分叙述专题会议和壁报的内容 ,其中又分为 3个方面 ,即放射诊断学 (包括介入放射学 )、核医学和放射治疗。     

Fiber Optic Signal Attenuation by Secondary Ionizing Radiation in Nuclear Environments

Irradiation of optical fiber waveguides by ionizing radiation can cause an increased loss in optical transmission. The effect of the loss has been measured on several commercially available pure silica core boron-doped clad fibers irradiated with thermal neutrons from a nuclear reactor. In the present work, optical absorptions were measured over the 400-1100nm range during the neutron irradiation. We have found that the attenuation of optical transmission by thermal neutrons is caused by defects produced by alpha particles which are produced in boron-neutron reactions.     

Effects of Ionizing Radiation on Monolithic PMOS Inverters

The problem of radiation hardening of metal-oxidesemiconductor (MOS) systems is discussed from a circuit viewpoint. An inverter chain is studied, and its performance in radiation is related to device quality. Techniques for testing and hardening circuits are given.     

热休克蛋白对电离辐射损伤的保护效应

近年来,热休克蛋白（HSPs）对电离辐射损伤的保护效应成为一个关注的热点。本文综述了热休克蛋白家族及其对电离辐射损伤的保护效应,包括HSPs对细胞凋亡的抑制作用和DNA损伤的保护作用两方面,对热休克蛋白与电离辐射损伤的关系进行了探讨。     

Detailed Lumped-Model Analysis of Transistor Ionizing Radiation Effects

Transient response of a transistor exposed to an ionizing radiation environment can be predicted solely from knowledge of the radiation environment and transistor lumped-model parameters calculated from geometrical and electrical data. Accuracy of the lumped-model transistor representation depends on the detail and accuracy of the data used for calculation of the lumped-model parameter values, an accurate representation of the carrier generation rate in the semiconductor transistor chip, and an accurate representation of the interaction of the radiation environment and the transistor leads and package. In general, we have found that the detailed transistor model represents the common emitter transient response to well within a factor of two. The transistor response is calculated from electrical and geometrical data and the measurement of the radiation intensity from a silicon PIN detector. The transistor response is considered over the entire practical range of quiescent emitter current (<10 ?a to > 10 ma) and common-emitter source resistance (100 ohms to 10 kilohms).     

Transient Response of GaAs IC's to Ionizing Radiation

Transient responses of GaAs E-JFET planar integrated circuits caused by a 25 ns wide ionizing radiation pulse from a LINAC were measured. Present technology circuits with 2.5 ?m channel length devices have a measured logic upset level of about 1 × 1010 rad(GaAs)/s and a survival dose rate of approximately 1 × 1011 rad(GaAs)/s. A theoretical analysis for logic upset dose rate and a correlation of experimental results with theory is presented. For E-JFET devices with a channel length of 1 ?m, a logic upset dose rate of 1 × 1011 rad(GaAs)/s is predicted.     

SOS—CMOS电路的电离辐照响应特性

本文通过对ＳＯＳ－ＣＭＯＳ门电路４０８２进行不同偏置条件下的电离辐照实验，研究了电离辐照环境中引起ＳＯＳ－ＣＭＯＳ门电路失效的几种重要漏电机制，。探讨了ＳＯＳ－ＣＭＯＳ电离辐射损伤的最劣辐照偏置条件。     

Effect of Ionizing Radiation on Gunn Diode Amplifiers

X-band Gunn diode amplifiers have been tested while exposed to pulsed ionizing radiation. Peak photo currents induced vary as the .65 power of the dose rate, as had been found for oscillator diodes. The principal effect is a transient loss of gain, with the recovery time less than 400 ns for dose rates up to 5×1010 rad (Si)/s. The dependence of gain on dose rate agrees very well with a calculation based on the change in electric field distribution caused by radiation-induced excess carriers. A permanent failure mode was also observed at the maximum operating voltage and dose rate.     

关于电离辐射防护学科的定位与内涵

本文从学科的本质属性与特征出发,追踪评述百余年来新催生发展的电离辐射防护学科的定位及其内涵。同时,研讨这门多学科密切交叉融合的新兴边缘学科,历来已经形成的诸多个不全相同称谓的共同核心含义。显然,准确界定电离辐射防护学科的定位与内涵,必然很有利于电离辐射防护学科建设及其更好发展。     

细胞骨架与辐射所致神经细胞迁移障碍研究进展

微管和微丝的动态变化是正常细胞迁移的主要动力。电离辐射引发机体组织和细胞的生物效应与细胞骨架的改变密切相关,辐射引起微丝解聚微管聚合障碍,使神经细胞无法进入迁移模式或迁移异常。本文综述了辐射所致细胞骨架改变对神经细胞迁移的影响。     

电离辐射对男性生殖及内分泌功能的影响

性腺、甲状腺及肾上腺是人体对电离辐射敏感性较高的器官,是辐射防护的重点。本文介绍电离辐射对男性生殖和性腺功能的影响,以及对甲状腺、肾上腺皮质内分泌功能的影响。     

不同偏置下电流反馈运算放大器的电离辐射效应

在不同偏置条件下,对基于互补双极工艺生产的电流反馈运算放大器（CFA）进行了高低剂量率下的电离辐射效应研究。研究发现,在不同偏置条件下,器件损伤差异明显。在零偏条件下,器件在低剂量率下损伤显著增强,表现为低剂量率损伤增强效应（ELDRS）;在小工作电压下辐照时,器件损伤较小,且不同剂量率之间损伤差异不明显;而在大工作电压下辐照时,器件在高剂量率下的损伤明显大于低剂量率下的损伤,在随后的室温退火中,又恢复到与低剂量率损伤相当的程度,表现为时间相关效应。结果表明,双极器件是否具有ELDRS效应与实验偏置条件有重要关系。     

红沿河核电厂电离辐射计量标准的建立

根据红沿河核电厂γ辐射仪器、表面污染仪表的检定/校准需求,建立了电厂γ辐射标准装置和α/β表面污染仪检定装置。性能测试结果表明,装置的各项技术指标和性能满足相关国家标准要求。同时,介绍了电厂γ辐射标准装置和α/β表面污染仪检定装置的应用实例。     

电离辐射诱发的非靶效应及其生物学意义

辐射诱发的非靶效应包括基因组不稳定性、旁效应、断裂因子以及亲代受照射后的遗传效应。非靶效应在辐射致癌、辐射防护、放射治疗、辐射危险评估以及细胞衰老等方面有重要的生物学意义。本文主要从辐射诱发的基因组不稳定性和旁效应两方面介绍辐射诱发的非靶效应及其生物学意义。