L波段Si微波脉冲功率晶体管射频加速寿命试验

Si微波功率器件应用十分广泛,其可靠性直接影响使用设备的性能.以L波段Si微波脉冲功率晶体管为例,提出了一种基于Arrhenius模型的Si微波功率晶体管可靠性寿命评价方案.采用L波段Si微波脉冲功率晶体管在射频脉冲工作条件下(f=1.3 GHz,Pin=40 W,TW=150 μs,D=10%)进行了壳温为200℃的高温加速老化试验,应用Arrhenius模型对试验结果进行了分析和计算.推导得出了L波段Si微波脉冲功率晶体管在室温(25 ℃)工作条件下的平均寿命为6.2×106 h.     

C波段GaAs功率场效应晶体管可靠性快速评价技术

叙述了一咱快速评价GaAs微波功率场效应晶体管的方法－高温加速寿命试验，利用该方法对C波段GaAs功率场效应晶体管DX0011进行可靠性评估。在偏置VDS＝8V，IDS－375mA，沟道温度Tch=110℃下，10年的失效率λ≈27FIT。其主要失效模式是IDSS退化，激活能E－1．28eV。     

高频硅PNP晶体管3CG120高温失效机理研究

为了保证在高温条件下,正确使用高频硅PNP晶体管3CG120,文中对3CG120在不同温度段的失效机理进行了研究。通过对硅PNP型晶体管3CG120进行170～340℃温度范围内序进应力加速寿命试验,发现在170～240℃,240～290℃,以及290～340℃分别具有不同的失效机理,并通过分析得到了保证加速寿命试验中与室温相同的失效机理温度应力范围。     

C波段GaAs功率场效应晶体管可靠性快速评价技术

叙述了一种快速评价ＧａＡｓ微波功率场效应晶体管的方法——高温加速寿命试验，利用该方法对Ｃ波段ＧａＡｓ功率场效应晶体管ＤＸ００１１进行可靠性评估。在偏置Ｖ＿（ＤＳ）＝８Ｖ，Ｉ＿（ＤＳ）＝３７５ｍＡ，沟道温度Ｔｃｈ＝１１０℃，１０年的失效率λ≈２７ＦＩＴ。其主要失效模式是Ｉ＿（ＤＳＳ）退化，激活能Ｅ＝１．２８ｅＶ。     

微波晶体管可靠性预测

本报告给出了73.2～74.4所做的关于估价微波功率晶体管失效机理的结果,并给出了这些器件预期的可靠性和寿命结果。根据详细的失效分析进行了一系列加速射频寿命试验。估价了金和铝两种金属化系统器件。早期的工作是在 MSC1315和 PHI1510器件上进行的。PHI 型金金属化器件可在340℃结温下工作长达2000小时而不失效。MSC 型铝金属化器件在250℃结温下工作800小时或在310℃结温下工作10小时失效。其主要失效机理是电徙动。     

中功率微波砷化镓场效应晶体管可靠性研究

对WC55中功率微波砷化镓场效应晶体管进行的高温固定偏置加速寿命试验研究表明:该器件在70℃环境温度下的MTTF达7.3×10~5小时以上,已接近国外类似器件的可靠性水平;同时还揭示出器件早期失效模式有栅源烧毁、饱和漏电流下降及栅-源击穿电压降低等三种.根据加速寿命试验结果,提出了器件通过室温250小时LTPD为20%的工作寿命试验和500小时LTPD为15%的工作寿命试验的两种最佳筛选条件.室温工作寿命试验结果证明所提出的筛选条件是合理的.     

MCM-C基板上的多层互连及厚膜电阻的可靠性研究

重点研究了MCM-C基板中多层互连和厚膜电阻的可靠性.试验采用温度应力和电应力的双应力加速寿命试验.试验发现,温度小于180℃时互连失效在MCM-C基板失效中占主要地位,膜电阻失效相对互连失效可忽略不计.在温度高于180℃时膜电阻失效将起较大作用,即膜电阻比互连温度加速系数要大.重点计算了膜电阻和互连寿命分布及加速系数.     

航天InGaAs短波红外探测器步进应力加速寿命试验研究

随着航天应用InGaAs短波红外探测器的迅速发展,其可靠性问题日益突出。选择温度为加速应力,通过步进应力加速寿命试验方法对800×2双波段集成的InGaAs焦平面探测器进行了研究,获得了InGaAs焦平面模块失效机理保持不变的最大温度应力范围和失效模式,利用温度斜坡模型计算得到了样品的失效激活能,为进一步研究该器件的可靠性问题提供了依据。     

微波晶体管可靠性研究

用四种微波晶体管作了典型使用条件下的加速直流电徙动试验。获得了一个较低的激活能以及典型的电徒动方程的一个较大的指数项前的常数和较小的电流密度指数。三种晶体管也在2.0千兆赫下作了工作寿命试验。5000小时的试验后,直流和射频试验之间开始呈现出相互有关。振荡器失效而放大器未失效。金引线的功率循环中没有出现引线或键合的失效损坏。温度步进应力试验表明,一个半导体器件不能在其易熔的温度之上使用。用一个计算机模型计算高管壳温度和大功率负荷下的工作温度,这时难于进行和解释实际测量。     

Si微波功率晶体管加速寿命试验夹具的设计

温度应力的加速寿命试验结果与所用夹具的耐温性及壳温的精确测量与控制直接相关。通过大量研究,发现一体式夹具在试验壳温提高到某一值时性能迅速劣化,因此设计符合高温下使用的分离式夹具是加速寿命试验顺利进行的必要条件。提供了两种加速寿命试验夹具的设计思路,并用于Si微波功率管加速寿命试验,通过步进应力试验和恒定应力试验,获取了该Si微波功率管加速寿命。分体夹具可耐受的试验温度在260℃以上,为加速寿命试验提供了温度应力的提升空间。     

New aspects for lifetime prediction of bipolar transistors in automotive power wafer technologies by using a power law fitting procedure

Bipolar transistors are part of the design manuals of almost all semiconductor wafer technologies. These design library devices must be qualified and released according to the present qualification standards, e.g. AEC (automotive electronic council) or JEDEC [Automotive Electronic Council. AEC-Q100-Rev-F; 2003; Automotive Electronic Council. AEC-Q101-Rev-C; 2005; JEDEC JP-001. Foundry process qualification guideline; 2002]. Dedicated stress tests (e.g. high temperature electrical operation (HTEO), bias temperature stress (BTS) or emitter base reverse bias (EBRB)) must be performed to check device specific drift and degradation mechanisms. A lifetime prediction must be performed on base of the determined device parameter drifts.The mentioned qualifications tests are arranged at typical device application conditions for electrical operation and temperature. Due to the breakdown behaviour of bipolar transistors the electrical operation parameters are limited to the save-operation-area (SOA). This excludes the possibility of any acceleration during these tests. Based on this fact the final check of the requested device lifetime in customer applications can be performed only by non-accelerated end-of-life tests.The paper shows a review of typical stress tests of dedicated bipolar transistors of an automotive power wafer technology. A presentation of the drift behaviour of the current gain (beta) parameter as function of stress time and qualification test is presented. In order to replace the end-of-life test requirement and to find a new approach to estimate the expected lifetime in the final device application a power law fitting procedure will be introduced. New aspects to discuss these results with respect to the defined lifetime target will be shown.     

Reliability evaluation of a silicon-on-silicon MCM-D package

This paper presents the results of reliability testing on a multichip module technology with active silicon substrates. The modules use flip-chip technology to attach silicon chips to the active substrate and this assembly is then packaged into a plastic ball grid array package. Performance was evaluated using two custom designed test chips incorporating thermal, thermomechanical, electrical and reliability test structures. A rigorous environmental test sequence including temperature, cycling, humidity, highly accelerated stress test and power cycling were carried out on the demonstrators. A full destructive physical analysis was then performed, consisting of die/substrate shear, wire bond pull tests and microsectioning.     

宇航元器件极限评估试验剖面设计

宇航元器件极限评估是一种新的可靠性评价技术,其目的是评价电子元器件的极限能力,以适应航天对电子元器件的高可靠性要求。介绍了极限评估和极限评估试验,提出了极限评估试验剖面设计的一般原则,给出了试验剖面设计的典型方法,并以微波固态功放的温度应力极限评估试验和GaAs单片微波集成电路的电压应力极限评估试验作为典型样例设计了试验剖面,通过试验验证了剖面的有效性,最后总结了极限评估试验剖面设计中应当注意的一些事项。     

S波段大功率SiC MESFET的设计与工艺制作

针对SiC功率金属半导体场效应晶体管如何在实现高性能的同时保证器件长期稳定的工作,从金属半导体接触、器件制造过程中的台阶控制、氧化与钝化层的设计及器件背面金属化实现等方面进行了分析;并结合具体工艺,对比给出了部分实验结果。从测试数据看,研制的微波SiC MESFET器件性能由研制初期在S波段瓦级左右的功率输出及较低的功率增益和功率附加效率,达到了在实现大功率输出的条件下,比Si器件高的功率增益和30%以上的功率附加效率,初步体现了SiC MESFET微波功率器件的优势,器件的稳定性也得到了提升,为器件性能和可靠性的进一步提升奠定了设计和工艺基础。     

Investigation into the correct statistical distribution for oxide breakdown over oxide thickness range

A critical aspect of integrated circuit manufacturing is the reliability of the components, in particular the gate oxide of transistors and capacitors. There are two statistical distributions, which can be applied to accelerated stress test failure data, namely the Lognormal or the Weibull distributions. The failure data can fit each distribution equally well. However both distributions will give vastly different lifetime predictions and their correct use is crucial for accurate lifetime prediction. A statistical based test, developed with Monte Carlo data, which is designed to decide if a failure data set has an underlying Lognormal or Weibull distribution is applied to empirical Time Dependent Dielectric Breakdown (TDDB) failure tests. The TDDB tests are carried out on 7 nm, 15 nm and 20 nm thick gate oxides. The results generated show the importance of making the correct choice between the two distributions for accurate lifetime prediction and validate the test for different oxide thickness. Also investigated are the effects of choosing the incorrect statistical distribution has on the voltage and temperature acceleration factors.     

Negative Bias Temperature Instability in Low-Temperature Polycrystalline Silicon Thin-Film Transistors

The authors have proved that negative bias temperature instability (NBTI) is an important reliability issue in low-temperature polycrystalline silicon thin-film transistors (LTPS TFTs). The measurements revealed that the threshold-voltage shift is highly correlated to the generation of grain-boundary trap states. Both these two physical quantities follow almost the same power law dependence on the stress time; that is, the same exponential dependence on the stress voltage and the reciprocal of the ambient temperature. In addition, the threshold-voltage shift is closely associated with the subthreshold-swing degradation, which originates from dangling bond formation. By expanding the model proposed for bulk-Si MOSFETs, a new model to explain the NBTI-degradation mechanism for LTPS TFTs is introduced     

硅脉冲微波功率器件增益退化机理研究

介绍了硅双极型微波功率晶体管的发展历史和应用现状.针对硅脉冲微波功率器件增益退化的失效模式,通过对硅脉冲微波功率器件直流参数的统计分析,初步得出了其失效机理.     

不同脉冲工作条件对GaN HEMT器件结温的影响

研究了不同脉冲工作条件对GaN高电子迁移率晶体管(HEMT)结温的影响,通过改变脉冲信号发生器的输出频率和占空比来改变器件的工作条件,利用具备高空间分辨率的显微红外热像仪进行瞬态结温测试。结果表明:器件工作在给定的平均功率下,可以通过提高脉冲信号占空比和频率来改善器件的寿命和性能可靠性;工作在给定的峰值功率下,可以通过降低脉冲占空比和提高脉冲频率来改善器件的寿命和性能可靠性。沟道温度影响着半导体器件的寿命,因此,可以在器件能够承受的范围内通过改变脉冲占空比和脉冲频率来改善器件的寿命和性能可靠性。     

双层金属电极对硅功率晶体管结温的改善

通过红外热相分析发现,在直流工作条件下,双层金属电极硅功率晶体管芯片比单层金属电极的结温低10℃以上;在微波工作条件下,双层金属电极芯片的结温比单层金属电极的低43.7℃。试验结果表明,双层金属电极能够改善硅微波功率晶体管芯片内微波输入功率和结温分布的均匀性。