Dynamic power-equalized EDFA module based on strain tunable fiberBragg gratings

An adaptive power-equalized erbium-doped fiber amplifier (EDFA) module is proposed and experimentally demonstrated by using strain tunable fiber Bragg gratings (FBGs). In a demonstration for a five-channel wavelength-division-multiplexed (WDM) system, the EDFA module can effectively reduce the power variation from 11 dB to 0.3 dB. Measured power penalty for 2.5-Gb/s data is less than 0.5 and 1.1 dB for 5 and 17 dB of signal attenuation by tunable FBGs, respectively. The power-equalized EDFA module can find wide applications in WDM lightwave transmission systems     

Single event upset and total dose radiation effects on rad-hard SRAMs

Radiation hardened 16K and 64K CMOS SRAMs were tested at the Brookhaven SEU Test Facility. No failures of 16K SRAMs were observed at room temperature with any value of the feedback resistors. SEU cross section measured at elevated temperatures was a function of reduced feedback resistance. A difference was observed in critical LET forBr andAu ions. SEU cross section decreased at very high angles of incidence. After initial SEU testing, the 64K SRAM was degraded by proton total dose irradiation. An increase in the SEU cross section as well as imprinting of the memory pattern was observed. Test chips fabricated by the same technology were also submitted to proton radiation. Threshold voltage shift was measured for NMOS transistors with and without inversion bias. An increase in the density of interface states for both NMOS and PMOS transistors was measured by the charge-pumping technique. This research has been supported by the NASA grants NAG-5-929 and NAG-9-333.     

基于光纤光栅和环形器的高温度稳定性OADM的研究

报道了一种基于光纤光栅和环形器的高温度稳定性OADM。下载中心波长 15 5 2 .5 2nm ,邻道串扰小于 -2 5dB。采用负热膨胀系数的材料对光纤光栅进行封装 ,在环境温度范围为 -2 0℃～ 60℃时 ,中心波长变化 0 .0 0 2 2nm/℃ ,温度稳定性远高于未补偿光栅指标 0 .0 1nm/℃。     

飞秒激光在SiC晶体中制备高温环境用光栅

为了研究SiC晶体光学方面的应用,利用飞秒激光冷加工的特点,对SiC晶体进行精微加工,研究了激光脉冲功率和扫描速率对光栅单元的影响,选取适合SiC晶体飞秒加工的工作条件,分别在晶体表面与内部加工出高质量的光栅。对加工好的光栅进行衍射通光实验,计算其各级衍射角,从而验证加工好的光栅周期;并在1300℃高温下进行退火实验,退火前后,光栅参量无明显变化。结果表明,该光栅适合在高温环境下使用。     

集成电路总剂量加固技术的研究进展

对集成电路总剂量加固技术的研究进展进行了分析。集成电路技术在材料、器件结构、版图设计及系统结构方面的革新,促进了总剂量加固技术的发展。新的总剂量加固技术提高了集成电路的抗总剂量能力,延长了电子系统在辐射环境下的使用寿命。文中总结了近年来提出的新型的总剂量抗辐射加固技术,如采用Ag-Ge-S、单壁碳纳米管材料(SWCNT)、绝缘体上漏/源(DSOI)器件结构、八边形的门(OCTO)版图、备用偏置三模块冗余(ABTMR)系统等加固方法,显著提高了器件或电子系统的总剂量抗辐射能力。研究结果有助于建立完整的总剂量加固体系,提升抗辐射指标,对促进总剂量加固技术的快速发展具有一定的参考价值。     

针对深亚微米SRAM电路总剂量效应的最劣辐照表征研究

利用理论分析与试验验证手段研究了深亚微米SRAM（静态随机存取存储器）电路的最劣辐照效应。对各模块电路的辐照效应进行了详细分析：对于具备触发器结构的存储单元与运算放大器,对应的失效水平将与辐照过程中所存储状态具有极大相关性,此类电路倾向于存储或读取与辐照过程中所存储状态相同的状态值。设计了针对SRAM电路的最劣辐照测试方案,其中包含辐照后改变原有存储状态的写操作及针对改变后所存储状态进行的读操作。设计了针对容量8K位,特征尺寸0.25um的SRAM电路开展的辐照比对实验,利用该最劣辐照测试方案获取的抗总剂量水平（150krad(Si)）相对于常用的简单测试方案所获取数值（1Mrad(Si)）大大降低,说明常用的简单测试方案可能高估SRAM电路的抗辐照水平,同时验证了该最劣测试方案的合理性。     

Total dose and transient radiation effects on GaAs MMICs

To elucidate the effects of radiation on GaAs monolithic microwave integrated circuits (MMICs), radiation-induced changes in DC parameters of test FETs and in the measured microwave performance of MMICs were compared. Changes in material parameters determined from the DC results were used to model the observed microwave performance degradation. In addition, the effect of accumulated radiation damage in MMICs was studied in terms of the amplifier response to transient radiation pulses. The effect of 1-MeV electron irradiation on microwave response and transient radiation pulse response was measured in 0.5- to 12.5-GHz distributed amplifiers (ion-implanted) and in 28-GHz power amplifiers (with epitaxially grown active layers)     

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。     

Modeling total dose effects in narrow-channel devices

Exposure of MOSFET's to large doses of ionizing radiation causes bulk oxide charging and an increase in interface state density. The former shifts device operation thresholds. The latter degrades channel mobility gmand increases subthreshold leakage. The degree of damage introduced depends on oxide electric fields. Making gate dimensions smaller complicates modeling a number of ways. Some of these complications are addressed in this paper. Specifically, problems associated with narrowing the width of the device channel are investigated. It is shown that differential charging of the field and gate regions leads to an effective widening of the channel. For typical n-channel MOSFET's used in very-large-scale integrated circuits, this widening may amount to 0.3 µm after a 10-krad:SiO2dose of ionizing radiation. A model incorporating channel widening and radiation-induced mobility degradation is proposed.     

A total dose radiation model for deep submicron PDSOI NMOS

In most of the total dose radiation models,the drift of the threshold voltage and the degradation of the carrier mobility were only studied when the bulk potential is zero.However,the measured data indicate that the total dose effect is closely related to the bulk potential.In order to model the influence of the bulk potential on the total dose effect,we proposed a macro model.The change of the threshold voltage,carrier mobility and leakage current with different bulk potentials were all modeled in this model,and the model is well verified by the measured data based on the 0.35μm PDSOI process developed by the Institute of Microelectronics of the Chinese Academy of Sciences,especially the part of the leakage current.     

一种深亚微米PDSOI NMOS总剂量辐照模型

在以往的大部分总剂量辐照模型中,人们只研究体偏为0V时的阈值电压漂移以及迁移率退化。然而,测试数据表明总剂量辐照效应与体偏紧密相关,为了模拟体偏对总剂量效应的影响,本文提出了一个宏模型,宏模型包括阈值电压、迁移率、以及漏电在不同体偏下随总剂量的变化。基于中国科学院微电子研究所开发的0.35µm PDSOI工艺的NMOS测试数据很好的验证了此模型,尤其是漏电部分。     

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。     

Periodical rocking long period gratings in PANDA fibers for high temperature and refractive index sensing

We report periodical rocking long period gratings (PR-LPGs) in PANDA fibers fabricated with CO2 laser. The PR-LPGs achieve very high coupling efficiency of 19 dB with 12 periods and a 3.5° twist angle in just one scanning cycle, which is much more effective than the conventional CO2 laser fabrication technique. This type of LPGs exhibits polarization-selective resonance dips which demonstrate different sensitivities to environmental parameters. The high temperature and external refractive index sensitivities are measured simultaneously, so it can be used as a wavelength-selective polarization filter and sensor. This work has been supported by the National Natural Science Foundation of China (No.61605168), the Natural Science Foundation of Hebei Province (No.F2016203392), the College and University Natural Science Foundation of Hebei Province (No.QN2016078), the Science and Technology Project of Qinhuangdao City (No.201601B050), and the Intramural Doctoral Foundation of Yanshan Universtiy (No.B1011). E-mail:jinwa@ysu.edu.cn      

Transient and total dose radiation characteristics of an SOS LSI array

Transient and total dose characteristics of irradiated 300 gate LSI arrays are presented. These arrays are configured to carry out the arithmetic function of an Arithmetic-Logic Unit. Samples were fabricated with ion implanted source-drain regions, wet-or dry-oxide (SiO2) gate insulator, and n⁺deposited polysilicon gates. Irradiation sources were the AFCRL Linac operating with 20- and 100-ns pulses, and the Fort Monmouth Cobalt 60 facility. Transient upset measurements of four worst case outputs are presented with the samples operating in an active and static mode during exposure. Worst case is the static mode of operation during exposure. The upset dose rate during an active mode depends on the time of occurrence of the radiation pulse relative to the transition waveform. Functional failure doses made in-situ are presented for exposure dose rates ranging from 4.2 to 1000 krads (Si)/h. Corresponding total dose failure for these dose rates varies from 10⁵to 10⁶rads (Si). The rapid annealing properties of the gate insulator are responsible for this dependence on dose rate.     

Total dose radiation effects on CMOS ring oscillators operating during irradiation

Total dose radiation effects on propagation delay time were discussed, utilizing 1.5-µm CMOS/SOS ring oscillators with substrate electrodes, irradiated to 10⁵rad (Si) with power on. Propagation delay times after irradiation have been successfully predicted by circuit simulation, based on experimental NMOS and PMOS threshold shift data including gate bias dependence during irradiation. It has also been found that the substrate bias condition during irradiation significantly affects post-rad device characteristics. The importance of taking into account substrate bias condition during irradiation in regard to an irradiated scaled circuit performance prediction, is discussed based on the above mentioned results.     

环境温度对SiC MOSFET的总剂量辐射效应影响

开展不同温度下碳化硅(SiC)金属-氧化物半导体场效应晶体管(MOSFET)总剂量效应研究。采用⁶⁰Coγ射线对三款国内外生产的SiC MOSFET器件进行总剂量辐照试验,获得器件阈值电压、击穿电压、导通电阻、漏电流等参数分别在25℃,100℃,175℃下的辐射损伤特性,比较器件在不同温度下辐照后器件的退化程度。仿真实验结果表明,不同器件的阈值电压、静态漏电流以及亚阈特性等辐射损伤变化都表现出对环境温度的敏感性,而导通电阻、击穿电压等则相对不敏感。此外SiC MOSFET总剂量辐射响应特性对环境温度的敏感性,还随生产厂家的不同而呈现明显差异性。分析认为,在其他条件相同情况下,器件的阈值电压、静态漏电等参数的退化程度随着辐照温度的升高而降低,主要是由于高温辐照时器件发生隧穿退火效应引起。     

非平面三栅场效应晶体管总剂量辐射研究

This paper investigates the total ionizing dose response of different non-planar triple-gate transistor structures with different fin widths. By exposing the pseudo-MOS transistor to different amounts of radiation, different interface trap densities and trapped-oxide charges can be obtained. Using these parameters together with Altal 3D simulation software, the total dose radiation response of various non-planar triple-gate devices can be simulated. The behaviors of three kinds of non-planar devices are compared.     

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.     

光纤布拉格光栅温度补偿研究

提出了一种新颖结构的光纤光栅温度补偿器件,它由两种不同的热膨胀系数的材料组成。利用该器件实现了光纤光栅的温度补偿。在-18~50℃温度范围内光栅波长变化0.028nm,是未补偿光纤光栅的1/23倍。     

High birefringence fibre Bragg gratings written in tapered photonic crystal fibre with femtosecond IR radiation

High birefringence Bragg gratings were written with ultrafast 800 nm radiation in non-birefringent pure silica core photonic crystal fibres (PCF) that were tapered with an oxy-hydrogen flame. The grating spectra indicate that a birefringence above 10^-3 was created in the tapered PCF