p型金属氧化物半导体场效应晶体管低剂量率辐射损伤增强效应模型研究

对一种非加固4007电路中p型金属氧化物半导体场效应晶体管(PMOSFET)在不同剂量率条件下的电离辐射损伤效应及高剂量率辐照后的退火效应进行了研究. 通过测量不同剂量率条件下PMOSFET的亚阈I-V特性曲线,得到阈值电压漂移量随累积剂量、退火时间的变化关系. 实验发现,此种型号的PMOSFET具有低剂量率辐射损伤增强效应. 通过描述H⁺在氧化层中的输运过程,解释了界面态的形成原因,初步探讨了非加固4007电路中PMOSFET低剂量率辐射损伤增强效应模型. 关键词： p型金属氧化物半导体场效应晶体管 60Co γ射线')" href="#">⁶⁰Co γ射线 电离辐射损伤 低剂量率辐射损伤增强效应     

沟槽型发射极SiGe异质结双极晶体管新结构研究

提出了一种沟槽型发射极SiGe异质结双极晶体管新结构.详细分析了新结构中沟槽型发射极的引入对器件性能的影响,并对其机理进行研究.新型发射极结构通过改变发射极电流路径使电阻分区并联,在不增大结电容的前提下,有效减小发射极电阻,提高器件的频率特性.结果表明,新结构器件的截止频率和最大振荡频率分别增加至100.2 GHz和134.4 GHz,更重要的是沟槽型发射极结构的引入,在提高器件频率特性的同时,不会降低器件的电流增益,也不会增加结电容,很好实现了频率特性、电流增益和结电容之间的折中.对沟槽型发射极进行优化设计,改变侧墙高度和侧墙宽度.沟槽型发射极电阻不受侧墙高度改变的影响,频率性能不变;侧墙宽度增加,频率性能降低.     

沟槽型发射极SiGe异质结双极化晶体管新结构研究

提出了一种沟槽型发射极SiGe异质结双极化晶体管新结构. 详细分析了新结构中沟槽型发射极的引入对器件性能的影响,并对其机理进行研究. 新型发射极结构通过改变发射极电流路径使电阻分区并联,在不增大结电容的前提下,有效减小发射极电阻,提高器件的频率特性. 结果表明,新结构器件的截止频率和最大振荡频率分别增加至100.2 GHz和134.4 GHz,更重要的是沟槽型发射极结构的引入,在提高器件频率特性的同时,不会降低器件的电流增益,也不会增加结电容,很好实现了频率特性、电流增益和结电容之间的折中. 对沟槽型发射极进行优化设计,改变侧墙高度和侧墙宽度. 沟槽型发射极电阻不受侧墙高度改变的影响,频率性能不变;侧墙宽度增加,频率性能降低. 关键词： SiGe 异质结双极化晶体管 沟槽型发射极 发射极电阻     

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.     

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.     

浮栅ROM集成电路空间低剂量率辐射失效时间预估

利用60Coγ射线开展了浮栅ROM集成电路（AT29C256）总剂量辐照实验， 研究了集成 电路功耗电流和出错数在不同剂量率下的辐射响应；按照定义的失效标准和外推实验技术， 探索了集成电路参数失效与功能失效时间随辐射剂量率的变化关系；根据失效时间与辐射剂 量率的函数关系，预估了浮栅ROM集成电路AT29C256(9911)和AT29C256(9939)空间低剂量率辐射失效时间. 关键词： 低剂量率 辐射损伤 失效时间 总剂量     

双极晶体管的系统电磁脉冲与剂量率综合效应

建立典型半导体器件系统电磁脉冲与剂量率综合效应计算模型,对在瞬态X射线辐照下电缆末端典型n+-p-n-n+结构的双极晶体管负载的系统电磁脉冲与剂量率综合效应进行研究,得到了综合效应现象,分析了综合效应机理,总结了综合效应规律。在系统电磁脉冲与剂量率综合效应作用下,双极晶体管内部,由于载流子数量剧增,其反向击穿阈值降低,综合效应比单一效应更易造成双极晶体管的毁伤。编制的系统电磁脉冲与剂量率综合效应计算程序可用于分析电子学系统中其他类型半导体器件的效应机理与规律。     

双极晶体管的系统电磁脉冲与剂量率综合效应

建立典型半导体器件系统电磁脉冲与剂量率综合效应计算模型,对在瞬态X射线辐照下电缆末端典型n+-p-n-n+结构的双极晶体管负载的系统电磁脉冲与剂量率综合效应进行研究,得到了综合效应现象,分析了综合效应机理,总结了综合效应规律。在系统电磁脉冲与剂量率综合效应作用下,双极晶体管内部,由于载流子数量剧增,其反向击穿阈值降低,综合效应比单一效应更易造成双极晶体管的毁伤。编制的系统电磁脉冲与剂量率综合效应计算程序可用于分析电子学系统中其他类型半导体器件的效应机理与规律。     

双极集成电路低剂量率辐射损伤增强效应的高温辐照加速实验

选择了四种典型双极集成电路,在两种不同剂量率下,开展了不同温度的高温辐照加速实验,测量了典型双极集成电路的辐射敏感参数在不同高温辐照下的变化规律。实验结果表明:高温辐照能够给出空间低剂量率辐射损伤增强效应的保守估计,且存在最佳辐照温度,最佳辐照温度随总剂量的增加向低温区漂移,随剂量率的增大向高温区漂移,在相同剂量率和总剂量下,输入级为NPN晶体管的双极集成电路比输入级为PNP晶体管的最佳辐照温度低。     

Degradation mechanisms of current gain in NPN transistors

An investigation of ionization and displacement damage in silicon NPN bipolar junction transistors (BJTs) is presented. The transistors were irradiated separately with 90-keV electrons, 3-MeV protons and 40-MeV Br ions. Key parameters were measured {\em in-situ} and the change in current gain of the NPN BJTS was obtained at a fixed collector current (I_{\rm c}=1~mA). To characterise the radiation damage of NPN BJTs, the ionizing dose D_{\i} and displacement dose D_{\d} as functions of chip depth in the NPN BJTs were calculated using the SRIM and Geant4 code for protons, electrons and Br ions, respectively. Based on the discussion of the radiation damage equation for current gain, it is clear that the current gain degradation of the NPN BJTs is sensitive to both ionization and displacement damage. The degradation mechanism of the current gain is related to the ratio of D_{\rm d}/(D_{\rm d}+D_{\rm i}) in the sensitive region given by charged particles. The irradiation particles leading to lower D_{\rm d}/(D_{\rm d}+D_{\rm i}) within the same chip depth at a given total dose would mainly produce ionization damage to the NPN BJTs. On the other hand, the charged particles causing larger D_{\rm d}/(D_{\rm d}+D_{\rm i}) at a given total dose would tend to generate displacement damage to the NPN BJTs. The Messenger--Spratt equation could be used to describe the experimental data for the latter case.     

An investigation of electron and oxygen ion damage in Si npn RF power transistors

Abstract

The effects of 8 MeV electrons and 60 and 95 MeV oxygen ions on the electrical properties of Si npn RF power transistors have been investigated as a function of fluence. The dc current gain (h _FE), displacement damage factor, excess base current (Δ I _B=I _Bpost?I _Bpre), excess collector current (Δ I _C=I _Cpost?I _Cpre), collector saturation current (I _CS) and deep level transient spectroscopy trap signatures of the irradiated transistors were systematically evaluated.     

Effect of bias condition on heavy ion radiation in bipolar junction transistors

The characteristic degradations in a silicon NPN bipolar junction transistor(BJT) of 3DG142 type are examined under irradiation with 40-MeV chlorine(Cl) ions under forward,grounded,and reverse bias conditions,respectively.Different electrical parameters are in-situ measured during the exposure under each bias condition.From the experimental data,a larger variation of base current(I B) is observed after irradiation at a given value of base-emitter voltage(V BE),while the collector current is slightly affected by irradiation at a given V BE.The gain degradation is affected mostly by the behaviour of the base current.From the experimental data,the variation of current gain in the case of forward bias is much smaller than that in the other conditions.Moreover,for 3DG142 BJT,the current gain degradation in the case of reverse bias is more severe than that in the grounded case at low fluence,while at high fluence,the gain degradation in the reverse bias case becomes smaller than that in the grounded case.     

Dose rate effect of gamma on JFET transistors

Dose rate effects on the noise characteristics of gamma-irradiated junction field effect transistors (JFETs) are presented. The dose rate varied between 0.5 and 19 kGy/h at a constant radiation dose of 600 kGy. Neither obvious nor non-general relationship was identified between noise and dose rate along the total dose rate range. Nevertheless, some explanations have been provided about the resulting effects when the total range was studied, as some partial ranges corresponded to low, medium and high dose rates. This explanation is based on the gamma interaction process in JFET structure and the electronic noise resulted.     

Study of total ionizing dose radiation effects on enclosed gate transistors in a commercial CMOS technology

This paper studies the total ionizing dose radiation effects on MOS (metal-oxide-semiconductor) transistors with normal and enclosed gate layout in a standard commercial CMOS (compensate MOS) bulk process. The leakage current, threshold voltage shift, and transconductance of the devices were monitored before and after $\gamma $-ray irradiation. The parameters of the devices with different layout under different bias condition during irradiation at different total dose are investigated. The results show that the enclosed layout not only effectively eliminates the leakage but also improves the performance of threshold voltage and transconductance for NMOS (n-type channel MOS) transistors. The experimental results also indicate that analogue bias during irradiation is the worst case for enclosed gate NMOS. There is no evident different behaviour observed between normal PMOS (p-type channel MOS) transistors and enclosed gate PMOS transistors.     

Si_3N_4钝化层对横向PNP双极晶体管电离辐射损伤的影响机理

航天器中电子器件在轨服役期间,会遭受到空间带电粒子及各种射线的辐射环境的显著影响,易于造成电离辐射损伤.本文采用60Coγ射线辐照源,针对有/无Si_3N_4钝化层结构的横向PNP型(LPNP)双极晶体管,开展了电离辐射损伤效应及机理研究.利用KEITHLEY 4200-SCS半导体参数测试仪测试了LPNP晶体管电性能参数(包括Gummel特性曲线和电流增益等).采用深能级瞬态谱分析仪(DLTS),对辐照前后有/无Si_3N_4钝化层结构的LPNP晶体管的电离缺陷进行测试.研究结果表明,在相同吸收剂量条件下,与无Si_3N_4钝化层的晶体管相比,具有Si_3N_4钝化层的LPNP晶体管基极电流退化程度大,并且随吸收剂量的增加,电流增益退化更为显著.通过DLTS分析表明,与无Si_3N_4钝化层的晶体管相比,有Si_3N_4钝化层的晶体管辐射诱导的界面态能级位置更接近于禁带中心.这是由于制备Si_3N_4钝化层时引入了大量的氢所导致,而氢的存在会促使辐射诱导的界面态能级位置更接近于禁带中心,复合率增大,从而加剧了晶体管性能的退化.     

Incident particle range dependence of radiation damage in a power bipolar junction transistor

The characteristic degradations in silicon NPN bipolar junction transistors(BJTs) of type 3DD155 are examined under the irradiations of 25-MeV carbon(C),40-MeV silicon(Si),and 40-MeV chlorine(Cl) ions respectively.Different electrical parameters are measured in-situ during the exposure of heavy ions.The experimental data shows that the changes in the reciprocal of the gain variation((1/β)) of 3DD155 transistors irradiated respectively by 25-MeV C,40-MeV Si,and 40-MeV Cl ions each present a nonlinear behaviour at a low fluence and a linear response at a high fluence.The(1/β) of 3DD155 BJT irradiated by 25-MeV C ions is greatest at a given fluence,a little smaller when the device is irradiated by 40-MeV Si ions,and smallest in the case of the 40-MeV Cl ions irradiation.The measured and calculated results clearly show that the range of heavy ions in the base region of BJT affects the level of radiation damage.