双极器件和电路的不同剂量率的辐射效应研究

对不同类型和型号的国产及进口双极晶体管和运算放大器的不同剂量率的辐照效应及退火特性进行了研究。结果表明:在辐照的剂量率范围内,无论是国产还是进口的双极晶体管,都有明显的低剂量率辐照损伤增强现象,且NPN管比PNP管明显。双极运算放大器的研究结果显示:不同电路间的辐照响应差异很大,对有些电路而言,剂量率越低,损伤越大。有些电路虽有不同剂量率的辐照损伤差异,但这种差异可通过室温退火得到消除,因而只是时间相关的效应。文中对引起双极器件辐照损伤差异的机理进行了探讨。     

运算放大器不同剂量率的辐射损伤效应

对几种不同类型（TTL,CMOS,JFETBi,MOSBi）的典型星用运算放大器在不同剂量率（100,10,1及0.01rad(Si)/s）辐照下的响应规律及随时间变化的退火特性进行了研究．结果显示不同类型运放电路的辐照响应有明显差异：双极运放电路辐照剂量率越小,其损伤越大;CMOS运放电路对不同剂量率的响应并非线性关系,但不同剂量率辐照损伤的差异,可以通过与低剂量率相同时间的室温退火得到消除,本质上仍然是与时间相关的效应;JFET输入运放不仅有低剂量率辐照损伤增强效应存在,且辐照后还有明显的“后损伤”现象;PMOS输入运放的结果则表明,各辐照剂量率间的损伤无明显区     

运算放大器不同剂量率的辐射损伤效应

对几种不同类型(TTL,CMOS,JFET-Bi,MOS-Bi)的典型星用运算放大器在不同剂量率(100,10,1及0.01rad(Si)/s)辐照下的响应规律及随时间变化的退火特性进行了研究.结果显示不同类型运放电路的辐照响应有明显差异:双极运放电路辐照剂量率越小,其损伤越大;CMOS运放电路对不同剂量率的响应并非线性关系,但不同剂量率辐照损伤的差异,可以通过与低剂量率相同时间的室温退火得到消除,本质上仍然是与时间相关的效应;JFET输入运放不仅有低剂量率辐照损伤增强效应存在,且辐照后还有明显的"后损伤"现象;PMOS输入运放的结果则表明,各辐照剂量率间的损伤无明显区别.     

不同辐射剂量率下CMOS器件的电离辐射性能

对加固ＣＭＯＳ器件在两种辐射剂量率下进行辐照实验,研究了ＭＯＳＦＥＴ阈值电压及ＣＭＯＳ倒相器转换电压Ｖｔｒ、开门电压Ｖｉｈ、关门电压Ｖｉｌ等参数随辐射剂量及辐射剂量率的变化关系规律．对实验结果进行了分析讨论     

双极晶体管高温辐照的剂量率效应研究

文章对一种具有低剂量率辐射损伤增强效应的国产双极晶体管进行了不同剂量率、不同温度下的电离辐照试验。结果表明，室温辐照条件下，该双极器件在较高剂量率下的辐射损伤没有显著区别，但在低剂量率辐照下，辐射损伤明显增加；而在高温辐照条件下，即使辐照剂量率较高，其辐射损伤也有显著的差异。最后，讨论了这种效应可能的内在机制。     

双极晶体管不同脉宽γ剂量率效应研究

介绍了晶体管在脉冲γ辐射源辐照下光电流的产生机理、测量方法，以及二次光电流结构、γ剂量率和γ波形宽度的关系。在现有的实验条件下（四种γ脉冲辐射率，宽度分别为：～２ｎｓ、２０ｎｓ，～６０ｎｓ，１００ｎｓ，剂量率为１０＾５～１０＾６ｙ／ｓ），对三种晶体管进行了辐照，对其等效关系进行了分析，得到了二次光电流与总剂量基本成绩性关系的结论。     

反熔丝FPGA器件γ剂量率辐射效应规律探讨

FPGA系统电路进行抗γ剂量率器件选择是非常困难的。针对FPGA器件抗γ剂量率性能优选,试验研究了3种反熔丝FPGA器件的7剂量率辐照效应规律。全部样品均出现了低阈值γ剂量率扰动效应,但均未产生高γ剂量率闭锁效应。FPGA器件低阚值γ剂量率失效主要是瞬时光电流扰动引起了时序逻辑功能的失效,而其模块海间的反熔丝开关电阻却对产生闭锁效应的大的辐射浪涌电流提供了保护。实验结果表明,系统电路设计加固是其实现抗γ剂量率最有效的方法。     

低剂量率下MOS器件的辐照效应

对MOS器件在低剂量率γ射线辐射条件下的偏置效应进行了研究。对不同偏置及退火条件下MOS器件辐照后的阈值电压漂移进行了对比。结果表明，偏置在MOS器件栅氧化层内产生电场，增强了辐照产生电子-空穴对的分离，同时，影响了正电荷（包括空穴和氢离子）的运动状态；此外，偏置对退火同样有促进作用。     

双极运算放大器ELDRS效应的变剂量率加速模拟方法初探

采用不同的变剂量率加速评估方法,研究了在不同辐照温度、不同辐照总剂量条件下,运算放大器电路随高剂量率转换到低剂率的辐射变化规律.结果表明,辐照时的转换总剂量、辐照温度及辐照剂量率均会对器件的响应特性产生影响,采用合适的变剂量率辐照方法可以达到既缩短辐照时间,又能加速评估器件ELDRS效应的目的.另外,对产生各种响应差异的机理进行了分析.     

不同剂量率下偏置对双极晶体管电离辐照效应的影响

对双极晶体管进行了不同剂量率、不同偏置的电离辐照实验。结果表明，对于不同偏置条件，晶体管在低剂量率辐照下，电流增益都有更为明显的衰降；各种剂量率辐照下，电流增益在发射结反向偏置时比浮空偏置时有更为显著的下降。文章对相关机理进行了探讨。     

电离辐射对CMOS运算放大器恒流偏置电路的影响

介绍了确定 CMOS运算放大器各级工作点的恒流源偏置电路随辐照总剂量变化的响应特征及其辐照敏感性对运放整体性能参数的影响规律。结果表明 ,恒流源特性的衰降对电参数的变化有一定的影响 ,但在一定范围内并不是造成辐射感生运放电参数衰变的最主要原因     

Mechanism of anomalous recovery in advanced SiGe bipolar transistors after low dose rate irradiation for very high total doses

The possible physical mechanism of the anomalous recovery effect in SiGe bipolar transistors is described. The qualitative analysis of saturated oxide trapped charge and interface trap densities at very high total doses as a function of dose rate affords an explain of decreasing excess base current and increasing current gain during further low dose rate irradiation.     

Total ionizing dose effects and annealing behavior for domestic VDMOS devices

Total dose effects and annealing behavior of domestic n-channel VDMOS devices under different bias conditions were investigated. The dependences of typical electrical parameters such as threshold voltage, breakdown voltage, leakage current, and on-state resistance upon total dose were discussed. We also observed the relationships between these parameters and annealing time. The experiment results show that: the threshold voltage negatively shifts with the increasing of total dose and continues to decrease at the beginning of 100 ℃ annealing; the breakdown voltage under the drain bias voltage has passed through the pre-irradiation threshold voltage during annealing behaving with a "rebound" effect; there is a latent interface-trap buildup (LITB) phenomenon in the VDMOS devices; the leakage current is suppressed; and on-state resistance is almost kept constant during irradiation and annealing. Our experiment results are meaningful and important for further improvements in the design and processing.     

国产VDMOS器件总剂量辐射及退火效应研究

本文研究了不同辐射偏置条件下国产VDMOS器件的总剂量辐射损伤及退火效应,探讨了阈值电压、击穿电压、漏电流、导通电阻等重要的电参数随累积剂量、退火时间的变化关系。实验结果表明：阈值电压随着累积剂量的增加反而减小,在高温退火初期继续降低;在100℃退火时,在漏偏置下的击穿电压恢复并超过了辐照前的值,发生了“回弹”现象;VDMOS器件出现了LITB现象;在辐照和退火时,漏电流得到了很好的抑制,导通电阻几乎没有变化。     

MOS器件及电路的总剂量辐射效应测试技术

介绍了半导体器件与电路的总剂量辐射效应及其测试技术,主要分析了MOS器件的效应机理、总剂量效应试验模拟源以及各种模拟源辐射环境的测量方法,最后给出了部分实验结果,并对其进行了讨论。     

Experimental studies of the adequacy of laser simulations of dose rate effects in integrated circuits and semiconductor devices

Comparative experimental studies of the responses of typical representatives of integrated circuits (ICs) and semiconductor devices (SDs) with various designs to high-energy pulsed ionizing radiations from simulation facilities and laser simulators have been carried out. The differences between the hardness values under exposure to radiations from simulation facilities and laser simulators have been found to be no larger than the dosimetry errors when the power supply ionization current calibration procedure is used. The shapes of power supply ionization currents and output voltages in the ICs are almost identical qualitatively. The levels and patterns of the functional IC failures are completely identical for both types of radiation sources. As a result, we have proven that a joint application of simulation facilities and laser simulators provides a rational combination of the reliability and efficiency of testing ICs and SDs for hardness to dose rate.     

Dynamic SVL and body bias for low leakage power and high performance in CMOS digital circuits

In this article, a new complementary metal oxide semiconductor design scheme called dynamic self-controllable voltage level (DSVL) is proposed. In the proposed scheme, leakage power is controlled by dynamically disconnecting supply to inactive blocks and adjusting body bias to further limit leakage and to maintain performance. Leakage power measurements at 1.8?V, 75°C demonstrate power reduction by 59.4% in case of 1?bit full adder and by 43.0% in case of a chain of four inverters using SVL circuit as a power switch. Furthermore, we achieve leakage power reduction by 94.7% in case of 1?bit full adder and by 91.8% in case of a chain of four inverters using dynamic body bias. The forward body bias of 0.45?V applied in active mode improves the maximum operating frequency by 16% in case of 1?bit full adder and 5.55% in case of a chain of inverters. Analysis shows that additional benefits of using the DSVL and body bias include high performance, low leakage power consumption in sleep mode, single threshold implementation and state retention even in standby mode.     

青紫心甘薯黄酮减轻60Co辐射诱导的小鼠胸腺淋巴细胞损伤的超微结构研究

目的:观察青紫心甘薯黄酮对60Co辐射损伤体外培养的小鼠胸腺淋巴细胞超微结构的影响.方法:建立单次60Co辐射损伤体外培养的小鼠胸腺淋巴细胞的病理模型,应用透射电镜观察细胞超微结构的变化.结果:在强度为3Gy 60Co辐射情况下,小鼠胸腺淋巴细胞超微结构在3 h后即出现核膜消失、核异染色质浓缩及边集、核碎裂、胞内空泡形成、线粒体嵴断裂、基质空泡化、粗面内质网扩张等典型细胞凋亡改变.2.500 g/L青紫心甘薯黄酮能抑制60Co辐射所致淋巴细胞的损伤,细胞的正常超微结构保存良好.结论:青紫心甘薯黄酮可有效地保护小鼠胸腺淋巴细胞对抗60Co的辐射损伤.