GaAs PHEMT器件高温加速寿命试验及物理分析

GaAs微波器件的退化与金属化稳定性密切相关,实现PHEMT器件功能的金属化主要有栅金属化、欧姆接触金属化和信号传输线金属化。本文针对定制的GaAs PHEMT器件的栅金属接触孔链和欧姆接触金属方块条进行了高温加速应力寿命试验,并对器件金属化失效单机理进行寿命预计,同时对试验后的样品进行物理分析。结果显示栅金属接触孔链在180℃下就发生失效,接触孔链表面的金属化层形变,金属化发生了迁移;而AuGeNi欧姆接触在225℃高温下更易发生电迁移失效,金属向体内扩散并在金属条上形成空洞。     

一种GaAs PHEMT器件的失效分析

随着Ga As PHEMT(赝配高电子迁移率晶体管)器件的广泛应用,器件的可靠性及失效分析方法越来越受到人们的重视。该文采用半导体参数分析仪、聚焦离子束(FIB)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、能谱仪(EDX)等分析方法对一种PHEMT器件进行失效分析,为实际生产和加工过程中的失效分析提供了参考。     

一种新的失效分析技术——光辐射检测技术

光辐射检测技术是一种新的失效分析技术，它能确定器件失效部位，区分失效机理，还可以进行光谱分析。这项技术可用来研究器件的ＰＮ结退化，寄生晶体管效应，热电子退化、、Ｉ／Ｏ保护电路中的ＥＳＤ技术，介质层漏电和击穿退化等，具有灵敏度高，非接触，非破坏的特点。本文对光辐射检测技术及其在器件失效分析方面的应用情况作了一个全面的介绍。     

砷化镓PHEMT功率管高温加速寿命试验研究

通过解决温度提升、温度稳定控制、寄生振荡抑制等关键问题,使砷化镓PHEMT功率器件的高温加速寿命试验得以实施。经过2 832h试验,三个分组的样品均出现了失效。对样品的失效模式与机理进行了分析,并确定了失效原因。对试验数据进行分析得到了该器件的寿命分布与寿命加速特性,并对分析结论进行了验证。     

微波MESFETs中金属—GaAs相互作用及接触退化

本文报道并回顾了中低功率ＧａＡｓ ＭＥＳＦＥＴｓ由于金属－ＧａＡｓ反应和接触退化造成失效的机理，这些结论是通过对不同工艺生产的商用器件进行深化和全面的可靠性评估实验得到的，结果表明：至少对于接触退化现象，这些生产工艺已经相当成熟，即使在最恶劣的使用条件和环境下，器件也达到了相当好的可靠性水平，某些厂家的器件仍然存在着可靠性问题，如：金基棚金属化向有源沟道的“沉陷”，Ａｌ的电徒动，被高接触电流密度加     

半导体器件参数退化失效分析

1 前言电参数漂移、超差或退化是半导体器件常见的失效模式。这类失效会导致产品合格率不高;使得成品器件档次下降;更严重的是还会影响整机的寿命和可靠性.引起这类失效的原因很多,如材料缺陷,生产工艺欠佳,使用条件、环境所致等等.但要对参漂或退化的器件进行分析时,由于这类失效的原因复杂,失效部位难寻,不像分析致命失效那样较直观,往往不易找到其失效原因。因此,如何准确确定这类失效器件的失效原因,是半导体器件生产厂家和用户长期以来乃至今依然十分关注的问题.本文通过两种型号晶体管的失效分析实例,介绍了对半导体器件参数退化失效原因的诊断分析方法。     

GaAs微波单片集成电路的主要失效模式及机理

从可靠性物理角角度，深入分析了引起砷化镓微波单片机集成电路（GaAs MMIC)退化或失效的主要失效模式及其失效机理，明确了GaAs MMIC的可靠性问题主要表现为有源器件、无源器件和环境因素等引入损伤退化，主要的失效部位是MMIC的有源器件。     

GaAs MESFET可靠性及快速评价新方法的研究

提出了一种快速评价GaAsFET可靠性寿命的新方法.利用GaAsFET失效敏感参数的温度特性和在一定电应力下的退化特性,及温度斜坡法在线快速提取器件失效敏感参数的退化量与温度的关系,从而进一步求出器件的失效激活能等相关的可靠性物理参数.     

电磁脉冲应力下MOS器件退化失效建模

通过分析电磁脉冲应力下,栅氧化层软击穿(MOS器件主要失效模式)的失效机理,得出结论:它符合基于随机过程的退化失效模型。根据此结论,提出利用该模型来描述电磁脉冲应力下MOS器件的退化失效过程,并给出相应的退化失效模型。同时针对退化失效模型中的失效阈值问题,研究了随机失效阈值问题,分析了周期电磁脉冲应力下MOS器件的失效阈值问题,给出动态应力-强度干涉(SS)I模型。这些为更合理描述和分析MOS器件的退化失效问题提供了新的途径。     

GaAs MESFET可靠性及快速评价新方法的研究

提出了一种快速评价GaAs FET可靠性寿命的新方法.利用GaAs FET失效敏感参数的温度特性和在一定电应力下的退化特性,及温度斜坡法在线快速提取器件失效敏感参数的退化量与温度的关系,从而进一步求出器件的失效激活能等相关的可靠性物理参数.     

白光LED老化机理研究进展

介绍了国内外在老化机理研究方面采用的加速老化方法,主要从深能级和非辐射复合中心的增加、接触电极金属的电迁移和退化、散热不良导致的电极缓慢或灾变性失效、封装材料的老化、荧光粉的劣变、静电的影响等方面来分析老化机理.同时介绍了根据这些研究而采取的各种改善措施.     

MMIC高温工作加速寿命试验失效机理分析

采用恒定功耗高温加速的试验方法,搭建了相关的试验系统,对高温工作寿命试验(HTOL)方法在功率GaAs MMIC领域的应用进行了一些探索。试验获得了对失效机理进行分析所需的失效数,所有样品的失效都是由同一原因引起的。通过监测数据和失效样品的分析,发现存在欧姆接触退化与栅金属下沉两种失效机理,但最终引起失效的机理单一,为栅金属下沉。     

Reliability of 70 nm metamorphic HEMTs

The reliability and degradation mechanisms of 70 nm gate length metamorphic InAlAs/InGaAs HEMTs for low noise applications will be presented and discussed. Based on a 10% g_{m max} failure criterion, a median time to failure of 10⁶ h and an activation energy of 1.3 eV in air were found. By comparing the electrical device characteristics before and after stress, gate sinking, ohmic contact degradation, and hot electron degradation were found to be the major failure mechanisms. The stress induced platinum diffusion into the semiconductor was quantified by cross-section TEM.     

Degradation of d.c. parameters in enhancement mode WNx self-aligned gate GaAs MESFETs under high temperature stress

The effect of thermal stress on the d.c. parameter degradation of enhancement mode tungsten nitride (WN_x) self-aligned gate GaAs MESFETs was investigated. Threshold voltage, source-drain current and transconductance were measured during the tests. The physical properties of the device after thermal stress were analyzed by means of Auger electron spectroscopy (AES), X-ray diffractometry to identify the degradation mechanism. The d.c. failure mode consists of an increase in the threshold voltage and a decrease in the current and transconductance of the FETs. The device simulator was also used for analytical understanding of the d.c. parameter degradation. The simulated results showed that d.c. parameter degradation was mainly attributed to the increase in source and drain ohmic contact resistances. From the AES analysis, we found that the increase of contact resistance was due to carrier compensation, which was caused by Ga outdiffusion and Ni indiffusion under the ohmic contact layer. Therefore the thermally activated carrier compensation effects by trap generation are proposed to be the main failure mechanism for d.c. parameter degradation of enhancement mode WN_x self-aligned gate GaAs MESFETs.     

电磁环境中电子器件的失效分析

以现在应用较广泛的电子器件-MOS器件在电磁环境中的失效建模为例,针对MOS器件受到电磁脉冲和周期脉冲的冲击后,所表现出来的失效特征,得出它符合基于随机过程的退化失效模型所描述的结论.根据结论和两种电应力的特点,分别提出基于随机过程的失效建模和动态应力-强度干涉建模.通过模型的建立和分析,初步制定出电子器件失效的试验方案.     

Degradation mechanism of GaAs MESFETs

The reliability of the Au/Pt/Ti Schottky gate of low-high doped GaAs MESFETs has been investigated by thermal step stress and accelerated life tests and their degradation mechanisms were analyzed by means of Auger electron spectroscopy, X-ray diffractometry, cross-sectional transmission electron microscopy, current-voltage, and capacitance-voltage measurements. Electrical measurements showed that the failure of the GaAs MESFETs was mainly due to the degradation of the Au/Pt/Ti/GaAs Schottky contact. An activation energy of 1.3 eV and a lifetime of 2 × 10⁸ h at 125°C for Schottky contact were evaluated. At a temperature lower than 350°C, the degradation of the Schottky contact is attributed to the decrease of net electron concentration caused by outdiffusion of host Ga atoms of GaAs. The activation energy for the decrease of net electron concentration is determined to be 1.4 eV using the capacitance-voltage measurement, which is consistent with 1.3 eV obtained by the accelerated life tests. This suggests that the major thermal degradation mechanism at a temperature lower than 350°C is the outdiffusion of Ga atoms from the channel. Meanwhile, the effective channel thickness at a temperature higher than 350°C is reduced by the formation of TiAs at the Schottky interface, the activation energy of which is determined to be 1.74 eV.     

不同的退化模式共存时产品退化失效分析

在高可靠性、长寿命产品的可靠性分析中,当产品的失效为退化型失效时,利用产品的性能退化数据进行可靠性分析是一种更合理的方法。在考虑产品既存在平稳退化,又存在随机退化时,研究了产品退化失效的一般模型并给出了模型参数的估计方法。最后,利用所给的模型对强激光装置所用的某型金属化膜脉冲电容器进行了可靠性分析,并验证了该方法的可行性。     

Effects of Electric Contact Failure on Signal Transmission in the Lossy Circuits

1　Introduction　Inrecentyears,thecommunicationandcomputernetworkshavedevelopedrapidly .Muchnewre searchworkneedstobedonetomeettheneedofthedevelopment.Itiswellknownthatelectricalcontactfailurecancauseserious problemsandsometimesevenmakethewholeelectronicorcommunicationsystemmalfunction .Itismainlyforthisreasonthatthecoaxialconnectorofhighqualityshouldbeusedinopticalcommunicationsystems.Butevidenceshaveprovedthatthecontactfailureofcoaxialcon nectorsusedinDigitalDistributionFrame (DDF)oftheop…     

Failure analysis on lattice matched GaInP/Ga(In)As/Ge commercial concentrator solar cells after temperature accelerated life tests

Accelerated life tests are frequently used to provide reliability information in a moderate period of time (weeks or months), and after that, a failure analysis is compulsory to detect the failure origins. In this paper, a failure analysis has been carried out after a temperature accelerated life test on lattice matched GaInP/Ga(In)As/Ge triple junction commercial solar cells. Solar cells were forward biased in darkness inside three climatic chambers in order to emulate the photo‐generated current under nominal working conditions (a concentration level of 820 suns). After the accelerated aging test, a characterization of the resulting cells by means of quantum efficiency, dark and illumination I–V curves, electroluminescence, scanning electron microscope, energy dispersive X‐ray, scanning transmission electron microscope and X‐ray photoelectron spectroscopy has been carried out. Current is identified as the cause of degradation while temperature just dominates the accelerating factor of the aging test. Current promotes the front metal damage produced by the chemical evolution of the electroplating impurities together with those of the tab soldering process. Semiconductor structure does not seem to be responsible of any failure. Therefore, this kind of lattice matched GaInP/Ga(In)As/Ge triple junction solar cells, that as of 2016, are the workhorse of CPV technology, exhibits as a very robust device if the front metal connection is properly accomplished. Copyright © 2016 John Wiley & Sons, Ltd.     

QFP封装互连结构电气特性建模与退化分析

互连结构是电子器件与印刷电路板之间机械固定及电气互联的关键部位.针对当前互连结构退化过程监测困难与表征信号难以提取问题,首先,通过分析QFP封装互连结构的失效模式及机理,建立其退化电气模型.在此基础上,搭建实时监测电路,选取外接电容的充电时间为表征信号,并建立退化电气模型参数与充电时间的关系.然后,利用Multisim软件和开发板模拟并验证等效电气模型参数与充电时间的关联关系.最后,利用小系统试验板进行随机振动试验,研究互连结构退化过程.通过分析充电时间响应,并结合互连结构电镜图发现,充电时间能够较好地表征互连结构的失效过程及失效模式.