Total ionizing dose effects on a radiation-induced BiMOS analog-to-digital converter

The total dose effect of an AD678 with a BiMOS process is studied.We investigate the performance degradation of the device in different bias states and at several dose rates.The results show that an AD678 can endure 3 krad(Si) at low dose rate and 5 krad(Si) at a high dose rate for static bias.The sensitive parameters to the bias states also differ distinctly.We find that the degradation is more serious on static bias.The underlying mechanisms are discussed in detail.     

12位CBCMOS工艺数模转换器电离辐射效应

A digital-to-analog converter （DAC） in CBCMOS technology was irradiated by 60Co F-rays at various dose rates and biases for investigating the ionizing radiation response of the DAC. The radiation responses show that the function curve and the key electrical parameters of the DAC in CBCMOS technology are sensitive to total dose and dose rates. Under different bias conditions, the radiation failure levels were different, and the radiation damage under operation bias conditions was more severe. Finally, test results were preliminarily analyzed by relating the failure mode to DAC architecture and process technology.     

Effect of total ionizing dose radiation on the 0.25 μm RF PDSOI nMOSFETs with thin gate oxide

Thin gate oxide radio frequency （RF） PDSOI nMOSFETs that are suitable for integration with 0.1μm SO1 CMOS technology are fabricated, and the total ionizing dose radiation responses of the nMOSFETs having four different device structures are characterized and compared for an equivalent gamma dose up to 1 Mrad （Si）, using the front and back gate threshold voltages, off-state leakage, transconductance and output characteristics to assess direct current （DC） performance. Moreover, the frequency response of these devices under total ionizing dose radiation is presented, such as small-signal current gain and maximum available/stable gain. The results indicate that all the RF PDSOI nMOSFETs show significant degradation in both DC and RF characteristics after radiation, in particular to the float body nMOS. By comparison with the gate backside body contact （GBBC） structure and the body tied to source （BTS） contact structure, the low barrier body contact （LBBC） structure is more effective and excellent in the hardness of total ionizing dose radiation although there are some sacrifices in drive current, switching speed and high frequency response.     

Method of simulation of low dose rate for total dose effect in 0.18 μm CMOS technology

Three methods for simulating low dose rate irradiation are presented and experimentally verified by using 0.18 μm CMOS transistors.The results show that it is the best way to use a series of high dose rate irradiations, with 100 °C annealing steps in-between irradiation steps, to simulate a continuous low dose rate irradiation.This approach can reduce the low dose rate testing time by as much as a factor of 45 with respect to the actual 0.5 rad（Si）/s dose rate irradiation.The procedure also provides detailed information on the behavior of the test devices in a low dose rate environment.     

Theoretical investigation of some parameters into the behavior of quantum dot solar cells

The main goal of this paper is to determine the accurate values of two parameters namely the surface generation–recombination rate and the average total number of electrons density generated in the i-region. These values will enhance the performance of quantum dot solar cells(QDSCs). In order to determine these values, this paper concentrates on the optical generation lifetime, the recombination lifetime, and the effective density state in QDs. Furthermore, these parameters are studied in relation with the average total number of electrons density. The values of the surface generation–recombination rate are found to be negative, which implies that the generation process is dominant in the absorption quantum dot region. Consequently, induced photocurrent density relation with device parameters is determined. The results ensure that QDSCs can have higher response photocurrent and then improve the power conversion efficiency. Moreover, the peak value of the average total number of electrons density is achieved at the UV range and is extended to the visible range, which is adequate for space and ground solar applications.     

Design of beam-wave interaction based on high efficiency of a high-power broadband klystron

The paper mainly presents the design of beam-wave interaction of a C-band high-peak- power high-efficiency broadband klystron. The beam-wave interaction section is designed based on considerations of efficiency and bandwidth synthetically. As a part of beam-wave interaction section, buncher section is simulated by Particle-In-Cell （PIC） code to observe the bunching process of electron beam to achieve high conversion efficiency of electron beam and RF field. When it comes to the other part, output circuit is designed as a three-section filter by an output cavity loaded with Chebyshev filter and the cold test results are given. The beam-wave interaction is simulated by EGUN code and Ar- senal-MSU code respectively. The simulated results indicated that, the existence of power dips in the operating bandwidth is verified by Arsenal-MSU code, comparing proper results by EGUN code. Then, the method that design parameters are not adjusted except parameters of buncher cavities to remove potential power dips is described. What is more, the simulated results of electron optics system are given by EGUN code and Arsenal-MSU code respectively. The further hot test results of klystron prove that the whole design of beam-wave interaction is effective.     

Design of a total-dose radiation hardened monolithic CMOS DC-DC boost converter

This paper presents the design and implementation of a monolithic CMOS DC-DC boost converter that is hardened for total dose radiation.In order to improve its radiation tolerant abilities,circuit-level and device-level RHBD(radiation-hardening by design) techniques were employed.Adaptive slope compensation was used to improve the inherent instability.The H-gate MOS transistors,annular gate MOS transistors and guard rings were applied to reduce the impact of total ionizing dose.A boost converter was fabricated by a standard commercial 0.35μm CMOS process.The hardened design converter can work properly in a wide range of total dose radiation environments,with increasing total dose radiation.The efficiency is not as strongly affected by the total dose radiation and so does the leakage performance.     

晶体管加速寿命研究

Choosing small and medium power switching transistors of the NPN type in a 3DK set as the study object,the test of accelerating life is conducted in constant temperature and humidity,and then the data are statistically analyzed with software developed by ourselves.According to degradations of such sensitive parameters as the reverse leakage current of transistors,the lifetime order of transistors is about more than 10~4 at 100℃and 100% relative humidity(RH) conditions.By corrosion fracture of transistor outer leads and other failure modes,with the failure truncated testing,the average lifetime rank of transistors in different distributions is extrapolated about 10~3. Failure mechanism analyses of degradation of electrical parameters,outer lead fracture and other reasons that affect transistor lifetime are conducted.The findings show that the impact of external stress of outer leads on transistor reliability is more serious than that of parameter degradation.     

EFFECT OF A WEAK LONGITUDINAL ELECTRIC FIELD ON WHISTLER WAVES

The effect of a longitudinal electric field on whistler waves is studied based onkinetic theory.A local Maxwellian distribution is taken as stationary distribution function ofelectrons which departs from thermodynamic equilibrium due to the applied electric field.Thedielectric tensor is derived by integrating along orbit of the particle in the unperturbed field.Dispersion relation and growth rate are analysed from Hermitian and anti-Hermitian parts ofthis tensor respectively.It is found that the waves are growing when the angle between the wavevector and the electric field is in range of θ<2θ_c, otherwise the whistler waves are damping.Thegrowth rate increases with wave frequency and decreases with the angle between the wave vectorand the applied field.In the case of ω_e(?)Ω the maximum of growth rate,which is at θ=O_l isproportional to the plasma density and anti-proportional to the magnetic field.Some computedresults for parameters at top of the F layer are given.     

基于分数阶小波的模拟电路参数估计* Deng Yong(邓勇)?, Zhang He(张禾)

Aiming at the problem of parameter estimation in analog circuits, a new approach is proposed. The approach is based on the fractional wavelet to derive the Volterra series model of the circuit under test(CUT). By the gradient search algorithm used in the Volterra model, the unknown parameters in the CUT are estimated and the Volterra model is identified. The simulations show that the parameter estimation results of the proposed method in the paper are better than those of other parameter estimation methods.     

运算放大器电离总剂量效应研究

对某型号国产双极型双路高压运算放大器在不同偏置条件和不同剂量率条件下的电离总剂量效应进行了研究。通过对运算放大器辐照前后的电参数进行测试,计算得到增强因子,分析特殊偏置条件和低剂量率条件对运算放大器电离总剂量效应的影响。试验结果表明,偏置条件不同,运算放大器的电离总剂量效应表现出明显差异性,各管脚短接相对于正常加电工作条件是较恶劣的一种偏置条件。在0.01 rad(si)/s低剂量率条件下,运算放大器表现出潜在的低剂量率增强效应。     

双极晶体管的低剂量率电离辐射效应

通过对npn管和pnp管进行不同剂量率的电离辐射实验,研究了双极晶体管的低剂量率辐射效应.结果表明,双极晶体管在低剂量率辐照下电流增益下降更为显著,这是由于低剂量率辐照在氧化层中感生了更多的净氧化物正电荷浓度,致使低剂量率下过量基极电流明显增大.而辐照后npn管比pnp管具有更大的有效表面复合面积,致使前者比后者有更大的表面复合电流,从而导致了在各种剂量率辐照下,npn管比pnp管对电离辐射都更为敏感.     

Influence of temperature and dose rate on the degradation of BiCMOS operational amplifiers during total ionizing dose testing

The degradation of BiCMOS operational amplifiers TLV2451CP under the gamma-irradiation is studied for different dose rates and temperatures during irradiation. It is shown that studied devices are sensitive to both enhanced low dose rate sensitivity and time-dependent effects. Evidently the main reason for degradation of studied devices is build-up of the interface traps. Obtained results show possibility to develop an approach for total ionizing dose testing of BiCMOS devices considering low dose rate effects.     

GaAs 10 bit DAC的抗辐射设计和实验

通过分析砷化镓(GaAs)器件的电离辐射剂量率辐照机理和效应,结合电路结构,描述了砷化镓10 bit数模转换器(DAC)的电离辐射剂量率辐射效应、抗辐射设计和辐照实验。在电路设计上,10 bit DAC由两个5 bit DAC组成,通过芯片内部合成10 bit DAC,有效降低了芯片面积和制造工艺难度;通过分析电路的电离辐射剂量率辐射效应,针对敏感电路进行局部电路的抗辐射设计,提高电路抗辐射能力;结合实验条件和器件引线分布,设计合理的辐照实验方案,开发辐照实验电路板,进行辐照实验,获得科学的实验结果,验证电路的抗辐射能力。实验结果表明该数模转换器能够抗3×1011rad(Si)/s剂量率的瞬时辐照。     

高压换流器辐射效应在线测试系统设计及应用

针对高压换流器类器件的电特性参数,设计了一种适合辐射效应在线测试的自动测试系统,适用于剂量率、总剂量与中子注量辐照试验中的参数测试。本文简述了系统测试功能和软硬件组成,并利用高压换流器SWM012RH完成了辐照试验测试验证。测试结果表明,检测系统能够完成主要参数的测试,高压测试精确度满足1%的要求,为开展高压换流器相关类型器件的辐照试验验证和抗辐射性能评估能力奠定了基础。     

辐照加固SRAM型FPGA总剂量辐射效应研究

在航天辐射环境中,电离辐射产生的辐射效应会对电子元器件性能产生影响。文章对自主研发的SRAM型FPGA芯片在60Co-γ源辐照下的总剂量辐射效应进行了研究。实验表明:(1)总剂量累积到一定程度后功耗电流线性增大,但只要功耗电流在极限范围内,FPGA仍能正常工作;(2)SRAM型FPGA在配置过程中需要瞬间大电流,故辐照后不能立即配置;(3)总剂量辐照实验时,功耗电流能直观反映器件随总剂量的变化关系,可作为判断器件失效的一个敏感参数。该研究为FPGA的设计提供了基础。     

Total ionizing dose sensitivity of function blocks in FRAM

The total ionizing dose (TID) sensitivity of the function blocks, including the memory array, sense amplifier, row decoder, column decoder and I/O port, of the ferroelectric random access memory (FRAM) are investigated. An X-ray microbeam is used for the selective irradiation and detailed detection. The ferroelectric memory array is proved to have higher resistance to TID than the peripheral control circuitry, whereas the sense amplifier is the most sensitive parts in the FRAM circuitry. The failure phenomenon is studied when each function block is irradiated, and the failure mechanism is discussed based on each block’s technological and circuital characteristics. In addition, the Co-60 γ ray irradiation test is also performed to offer a comparison of the spot and global irradiation.     

0.18μm浮栅Flash存储器件的总剂量辐射效应试验研究

针对自主设计的4 Mbit基于0.18μm商用CMOS flash工艺的浮栅flash存储器件进行了钴-60γ射线辐射效应试验研究.该存储器为FPGA的配置存储器.通过对被测器件分组,在加电配置和未加电配置条件下分别进行了钴-60γ射线辐射效应试验.试验实时监测了被测器件的工作电流以及其配置FPGA功能随总剂量变化的特...     

Total ionizing dose radiation effects on NMOS parasitic transistors in advanced bulk CMOS technology devices

In this paper, total ionizing dose effect of NMOS transistors in advanced CMOS technology are examined. The radiation tests are performed at ⁶⁰Co sources at the dose rate of 50 rad (Si)/s. The investigation''s results show that the radiation-induced charge buildup in the gate oxide can be ignored, and the field oxide isolation structure is the main total dose problem. The total ionizing dose (TID) radiation effects of field oxide parasitic transistors are studied in detail. An analytical model of radiation defect charge induced by TID damage in field oxide is established. The I-V characteristics of the NMOS parasitic transistors at different doses are modeled by using a surface potential method. The modeling method is verified by the experimental I-V characteristics of 180 nm commercial NMOS device induced by TID radiation at different doses. The model results are in good agreement with the radiation experimental results, which shows the analytical model can accurately predict the radiation response characteristics of advanced bulk CMOS technology device.