中子辐照诱导CCD电荷转移效率降低的数值模拟与分析

运用半导体器件二维数值模拟软件MEDICI,分别对能量为1 MeV和14 MeV的中子,在注量范围为3×1013～5×1014cm-2辐照下,对CCD器件电荷转移效率的变化规律进行数值模拟研究.建立了MEDICI软件模拟CCD电荷转移效率变化的器件物理模型、中子辐照模型,并对模拟结果进行了机理分析,得出中子辐照诱导CCD器件电荷转移效率降低的初步规律.     

CCD位移辐射效应损伤机理分析

研究了电荷耦合器件(CCD)位移辐射效应的损伤机理。分析了位移损伤诱发的体缺陷对CCD工作性能的影响。研究了位移损伤导致CCD电荷转移效率降低、体暗电流密度增大、暗电流尖峰以及随机电码信号(RTS)出现的规律和机理。     

GaN HEMT器件中子辐照效应实验研究

建立了GaN HEMT器件(氮化镓高电子迁移率晶体管)中子原位测试技术和辐照效应实验方法,开展了GaN HEMT器件脉冲反应堆中子辐照效应实验研究,重点研究了电离辐射和位移损伤对器件性能退化的影响,获取了GaN HEMT中子位移损伤效应敏感参数和效应规律.结果表明,阈值电压、栅极泄漏电流以及漏极电流是中子辐照损伤的敏感...     

CCD辐射损伤效应及加固技术研究进展

综述了电荷耦合器件(CCD)在空间环境和核辐射领域中的辐射效应研究进展;阐述了不同粒子辐照CCD的损伤效应机理及暗电流、平带电压和电荷转移效率等敏感参数的退化机制;从制造工艺、器件结构、工作模式等方面介绍了CCD抗辐射加固技术;分析了CCD辐射效应研究的发展趋势。     

不同偏置下CCD器件γ射线及质子辐射研究

电荷耦合器件(CCD)是用于空间光电系统可见光成像的图像传感器,在空间应用环境下受辐射效应作用导致CCD性能退化甚至失效。对于CCD空间辐射效应的地面模拟试验研究,辐照试验中CCD采用合适的偏置条件是分析其空间辐射损伤的必要措施。由于CCD对质子辐照导致的电离总剂量效应和位移损伤效应均非常敏感,因此针对CCD空间应用面临的电离总剂量效应和位移损伤效应威胁,开展不同辐照偏置下CCD的辐射效应及损伤机理研究。针对一款国产埋沟CCD器件,开展不同偏置条件下的γ射线和质子辐照试验,获得了CCD的暗电流、光谱响应等辐射敏感参数的电离总剂量效应,位移损伤效应退化规律以及辐照偏置对CCD辐射效应的影响机制。研究表明,γ射线辐照下CCD的偏置产生重要影响,质子辐照下没有明显的偏置效应。根据CCD结构和辐照后的退火试验结果,对CCD的辐射效应损伤机理进行分析。     

质子辐射环境下NPN输入运算放大器在不同偏置状态下的辐射效应

对NPN输入运算放大器LM741在不同偏置状态下进行了Co-60 γ射线辐照和3MeV与10MeV质子射线辐照以研究NPN输入运算放大器的质子辐照效应。通过比较Co-60 γ射线辐照和3MeV与10MeV质子射线辐照的实验结果可以发现,3MeV与10MeV质子射线辐照在LM741中主要产生电离损伤。在不同的偏置状态下,器件的损伤敏感程度不同,零偏置器件的输入偏置电流的退化明显高于正向偏置器件。对于相同吸收剂量的质子,质子通量的差别对器件的辐射效应影响很小。电源电流是另一个对质子辐照敏感的参数,Co-60 γ射线辐照和3MeV与10MeV质子射线辐照会对电源电流产生不同程度的影响,这是因为Co-60 γ射线辐照和3MeV与10MeV质子射线辐照引起的电离能量沉积和位移能量沉积不同     

质子辐照对超辐射发光二极管性能的影响

用能量分别为350keV和1MeV,注量为1×1012和1×1013p/cm2的质子对超辐射发光二极管(SLD)进行辐照,对辐照前后器件的光学和电学性能进行了测试.结果表明,在相同注量辐照的条件下,350keV与1MeV能量质子辐照引起的辐照损伤相比,前者引起的出光功率的退化更大,造成的辐照损伤更加严重.采用TRIM程序对质子入射到器件材料中的射程分布进行了模拟,初步探讨了SLD在350keV和1MeV能量质子辐照下的损伤效应.     

质子辐照对超辐射发光二极管性能的影响

用能量分别为350keV和1MeV,注量为1×1012和1×1013p/cm2的质子对超辐射发光二极管(SLD)进行辐照,对辐照前后器件的光学和电学性能进行了测试.结果表明,在相同注量辐照的条件下,350keV与1MeV能量质子辐照引起的辐照损伤相比,前者引起的出光功率的退化更大,造成的辐照损伤更加严重.采用TRIM程序对质子入射到器件材料中的射程分布进行了模拟,初步探讨了SLD在350keV和1MeV能量质子辐照下的损伤效应.     

典型电子器件中子和总剂量辐照协同损伤研究

研究了几种典型电源类电子器件的中子和总剂量辐射效应,包括单总剂量效应、单中子辐射效应、总剂量和中子分时序贯辐照效应以及中子和总剂量同时辐照效应,分析了不同辐照条件下电子器件的失效中子注量(总剂量)阈值。试验结果显示,分时序贯、同时辐照试验给出的电子器件辐照失效阈值低,而单项辐射效应试验给出的失效阈值偏高。对于该类双极工艺器件存在协同增强损伤的机理进行了分析,其主要原因在于同时辐照时,电离损伤在晶体管氧化层产生氧化物正电荷,使基区表面势增加,与此同时界面态数量增多,减少Si体内次表面载流子浓度的差异,从而使电流增益的退化加剧,增强晶体管的中子位移损伤。按照同时辐照进行试验考核,更能真实评估器件的综合抗辐射性能,研究结果对于器件抗辐射性能评估具有重要意义。     

电荷耦合器件信号电荷转移的数值模拟

建立了线阵埋沟CCD的器件物理模型和数值模拟方法;运用半导体器件模拟软件MEDICI,数值模拟了CCD信号电荷在三相时序脉冲驱动下动态转移过程;模拟计算了CCD电荷转移效率随信号电荷包大小的变化以及暗电子数随埋沟掺杂浓度大小的变化情况。数值模拟结果与理论分析、实验测试结果吻合较好。     

电荷耦合器件电离辐射损伤的模拟试验研究

利用钴-60源,在不同工作与辐照条件下,开展电荷耦合器件电离辐射损伤模拟试验,分析高低剂量率、器件偏置对器件暗电流信号增大和哑元电压漂移的影响,比较电荷耦合器件光敏单元、输出放大器总剂量效应的敏感性,研究辐射敏感参数与失效模式的差异.为建立电荷耦合器件电离辐射效应规范化的模拟试验与加固评估方法,提供技术基础.     

Simulation for signal charge transfer of charge coupled devices

Physical device models and numerical processing methods are presented to simulate a linear buried channel charge coupled devices (CCDs). The dynamic transfer process of CCD is carried out by a three-phase clock pulse driver. By using the semiconductor device simulation software MEDICI, dynamic transfer pictures of signal charges cells, electron concentration and electrostatic potential are presented. The key parameters of CCD such as charge transfer efficiency (CTE) and dark electrons are numerically simulated. The simulation results agree with the theoretic and experimental results.     

TCD132D线阵CCD总剂量效应的实验分析

研究了60Coγ辐照TCD132D线阵CCD的总剂量效应实验结果;分析了CCD受总剂量效应影响后暗信号和饱和输出电压的典型波形;得出了CCD分别在不加偏置电压、加偏置电压加驱动信号和加偏置电压不加驱动信号三种工作状态下,受60Coγ辐照后暗信号电压和饱和输出电压随总剂量累积的变化规律,并进行了损伤机理分析。     

CCD电荷转换因子通用测试方法研究

通过分析电荷耦合器件(CCD)图像传感器光电转换、电荷转移、电荷输出的工作原理,提出了一种通用高效的电荷转换因子(CVF)测试方法。该方法采用在CCD感光区域施加直流偏压,水平区施加连续转移的驱动时序的方式,使CCD光敏区以电荷溢出方式往水平区转移电荷,水平区以固定频率不间断转移输出电荷包,从而让CCD输出强度恒定的响应信号;然后通过复位漏电流与输出信号强度的对应关系计算出CCD器件的CVF值。根据该方法的原理设计了一种适应各种CCD器件的通用测试装置,并对多款CCD进行测试验证。结果表明,该方法有效提高了CCD电荷转换因子的测试效率、测试精度和稳定性。     

Synergistic effects of NPN transistors caused by combined proton irradiations with different energies

There are a large number of protons with different energies from the dozens of keV to hundreds of MeV in space environment, which simultaneously act on the bipolar junction transistors (BJTs), and induce different irradiation effect and damage defects. Moreover, interaction between displacement defects and ionization defects occurs. In the paper, the interaction mechanisms between oxide charge and displacement defects in 3DG112 NPN BJTs caused by the combined 70 keV and 170 keV protons with 5 MeV proton irradiation are studied. Experimental results show the degradation of current gain increases linearly with increasing the irradiation fluence of the 170 keV and 5 MeV protons, but increases nonlinearly for the 70 keV protons, implying that the 170 keV and 5 MeV protons mainly induce displacement damage on the NPN BJTs, while the 70 keV protons cause ionization damage. It can be seen from the Geant4 calculation that 70 keV and 170 keV protons cause almost the same ionization damage on the 3DG112 transistors, while have significant difference in displacement damage ability, which is favorable to analyze the effect of displacement damage in oxide layer of NPN BJTs induced by 170 keV and 70 keV protons on ionization damage caused by the subsequent 5 MeV protons. DLTS analyses show that 5 MeV protons produce mainly displacement defect centers in based-collector junction of 3DG112 transistors, and 170 keV and 70 keV protons only induce almost the same number of the oxide trapped charges. While the combined irradiation can produce the more oxide trapped charges, except displacement defects, showing that displacement damage in oxide layer caused by 170 keV and 70 keV protons can increase the oxide trapped charges during the subsequent 5 MeV exposures. Moreover, the more displacement defects in oxide layer will induce more oxide trapped charges, and give more enhanced synergistic effects. These results will help to assess the reliability of BJTs in the space radiation environment.     

The effect of ionization and displacement damage on minority carrier lifetime

Based on 1 MeV electrons and 40 MeV Si ion irradiations, the contribution of ionization and displacement damage to the decrease in the minority carrier lifetime of gate controlled lateral PNP (GLPNP) transistors is investigated by gate sweeping (GS) technique. Molecular hydrogen is employed to increase the ionization radiation sensitivity and help to understand the relationship between the minority carrier lifetime and ionization damage. Experimental results show that 1 MeV electrons mainly induce ionization damage to GLPNP transistors, 40 MeV Si ions primarily produce displacement defects in silicon bulk. For 40 MeV Si ions, with increasing the irradiation dose, the densities of interface trap and oxide charge are almost no change, the minority carrier lifetime obviously decreases. The decrease of the minority carrier lifetime is due to bulk traps induce by 40 MeV Si ions. For 1 MeV electrons, with increasing the irradiation dose, the densities of interface trap and oxide charge for the GLPNP with and without soaked in H₂ increase, and the minority carrier lifetime decreases. Compared with the GLPNP transistors without soaking in H₂, the density of the interface traps the irradiated GLPNP transistors by 1 MeV electrons and soaked in H₂ are larger and the minority carrier lifetime is lower. Therefore, both ionization and displacement damage can induce the decreases in the minority carrier lifetime including bulk minority carrier lifetime and surface minority carrier lifetime.     

Development and Testing of a 2-D Transfer CCD

This paper describes the development, operation, and characterization of charge-coupled devices (CCDs) that feature an electrode structure that allows the transfer of charge both horizontally and vertically through the image area. Such devices have been termed two-dimensional (2-D) transfer CCDs (2DT CCDs), as opposed to the conventional devices, which might be called one-dimensional transfer CCDs, but in other respects are the same as conventional CCD devices. Batches of two different 2DT CCD test devices, featuring different electrode structures but with identical clocking operation in each case, were produced and tested. The methodology of 2-D charge transfer in each of the device types is described, followed by a presentation of test results from the new CCDs. The ability of both 2DT CCD transfer electrode schemes to successfully transfer charge in both horizontal and vertical directions in the image section of the devices has been proven, opening up potential new applications for 2DT CCD use