基极注入强电磁脉冲对双极晶体管的损伤效应和机理

建立了双极晶体管(BJT)在强电磁脉冲作用下的二维电热模型, 对处于有源放大区的BJT在基极注入强电磁脉冲时的瞬态响应进行了仿真. 结果表明, BJT烧毁点位置随注入脉冲幅度变化而变化, 低脉冲幅度下晶体管烧毁是由发射结反向雪崩击穿所致, 烧毁点位于发射结柱面区; 而在高脉冲幅度下, 由基区-外延层-衬底组成的p-n-n⁺ 二极管发生二次击穿导致靠近发射极一侧的基极边缘率先烧毁; BJT的烧毁时间随脉冲幅度升高而减小, 而损伤能量则随之呈现减小-增大-减小的变化趋势, 因而存在一个极小值和一个极大值. 仿真与实验结果的比较表明, 本文建立的晶体管模型不但能预测强电磁脉冲作用下BJT内部烧毁发生的位置, 而且能够得到损伤能量. 关键词： 双极晶体管 强电磁脉冲 烧毁点位置 损伤能量     

不同样式的高功率微波对双极晶体管的损伤效应和机理

结合Si基n⁺-p-n-n⁺ 外延平面双极晶体管, 通过分析器件内部的温度分布变化以及电流密度和烧毁时间随信号幅值的变化关系, 研究了其在三角波信号、正弦波信号和方波脉冲信号等三种样式的高功率微波信号作用下的损伤效应和机理. 研究表明, 三种高功率微波信号注入下器件的损伤部位都是发射结, 在频率和信号幅值相同的情况下方波脉冲信号更容易使器件损伤; 位移电流密度和烧毁时间随信号幅值的增大而增大, 而位移电流在总电流所占的比例随信号幅值的增大而减小; 相比于因信号变化率而引起的位移电流, 信号注入功率在高幅值信号注入损伤过程中占主要作用. 利用数据分析软件, 分别得到了三种信号作用下器件烧毁时间和信号频率的变化关系式. 结果表明, 器件烧毁时间随信号频率的增加而增加, 烧毁时间和频率都符合t= af^b的关系式. 关键词： 双极晶体管 高功率微波 损伤机理 信号样式     

外电路在电磁脉冲对双极型晶体管作用过程中的影响

 借助自主开发的2维半导体器件-电路联合仿真器，研究了电磁脉冲从发射极注入双极型晶体管时，外电路的影响，分析了共基极接法晶体管的电流分配系数，然后在此基础上研究了3种典型外电路元件的影响。结果表明：当脉冲从发射极注入时，基极外接电阻对器件烧毁过程影响不大；集电极外接正电压源等效于削减电磁脉冲的幅度，有延缓器件烧毁的作用；集电极外接电阻能明显提高器件对电磁脉冲的耐受性。     

双极型晶体管损坏与强电磁脉冲注入位置的关系

 利用时域有限差分法，对双极型晶体管(BJT)在强电磁脉冲作用下的瞬态响应进行了2维数值模拟，研究了电磁脉冲从不同极板注入时BJT的响应情况，根据温度分布的集中程度分析了发生烧毁的难易程度。模拟得出：发射极注入最容易导致烧毁，集电极注入次之，基极注入相对不易导致烧毁；发射极注入烧毁所消耗能量随着脉冲电压上升而下降，到30 V以后基本与电压的升高无关，集电极注入烧毁所消耗的能量则随着电压上升而上升，到100 V以后由于BE结上热点的出现而开始下降。     

双极型晶体管在强电磁脉冲作用下的瞬态响应

 利用时域有限差分法,对双极型晶体管在强电磁脉冲作用下的瞬态响应进行了2维数值模拟,分析了器件烧毁过程中电场、电流密度、温度等参数的分布及变化情况,分别观察了低电压和高电压脉冲作用下烧毁过程中热点的形成过程,并得到了器件烧毁所需时间以及能量与脉冲电压幅度之间的关系。在电压脉冲较低时,烧毁点位于通道中靠近集电极的位置,当脉冲电压达到一定幅度的时候,由于发射极与集电极之间发生雪崩击穿,基极和发射极之间电势会抬高,从而引起基极和发射极之间的击穿,形成新的热点,并在电压幅度约高于100 V的情况下会率先达到烧毁温度。随着脉冲电压幅度的增高,晶体管烧毁所需时间呈负指数减少,而所需能量在55~100 V之间接近于线性增长,直到电压幅度约高于100 V时才开始减少。     

GaN高电子迁移率晶体管强电磁脉冲损伤效应与机理

提出了一种新型GaN异质结高电子迁移率晶体管在强电磁脉冲下的二维电热模型,模型引入材料固有的极化效应,高场下电子迁移率退化、载流子雪崩产生效应以及器件自热效应,分析了栅极注入强电磁脉冲情况下器件内部的瞬态响应,对其损伤机理和损伤阈值变化规律进行了研究.结果表明,器件内部温升速率呈现出"快速-缓慢-急剧"的趋势.当器件局部温度足够高时(2000 K),该位置热电子发射与温度升高形成正反馈,导致温度急剧升高直至烧毁.栅极靠近源端的柱面处是由于热积累最易发生熔融烧毁的部位,严重影响器件的特性和可靠性.随着脉宽的增加,损伤功率阈值迅速减小而损伤能量阈值逐渐增大.通过数据拟合得到脉宽τ与损伤功率阈值P和损伤能量阈值E的关系.     

基极注入强电磁脉冲对双极型晶体管的作用

 空间电磁脉冲注入硅双极型晶体管后可能会导致晶体管烧毁。借助2维数值仿真和理论分析研究了基极注入短电磁脉冲对双极型晶体管的作用，得出结论：晶体管的热斑位于基极边缘，由于该点既是电场峰所在,又是电流最密集之处，热量产生集中，因此基极注入脉冲使晶体管烧毁所需的能量比其它两电极注入要少；在基极注入短脉冲作用下，晶体管烧毁所需能量几乎不随脉冲宽度变化；烧毁所需脉冲功率近似与脉冲宽度成反比。     

双极晶体管微波损伤效应与机理

结合Si基n⁺-p-n-n⁺外延平面双极晶体管, 考虑了器件自热、高电场下的载流子迁移率退化和载流子雪崩产生效应, 建立了其在高功率微波(high power microwave, HPM)作用下的二维电热模型. 通过分析器件内部电场强度、电流密度和温度分布随信号作用时间的变化, 研究了频率为1 GHz的等效电压信号由基极和集电极注入时双极晶体管的损伤效应和机理. 结果表明集电极注入时器件升温发生在信号的负半周, 在正半周时器件峰值温度略有下降, 与集电极注入相比基极注入更容易使器件毁伤, 其易损部位是B-E结. 对初相分别为0和π的两个高幅值信号的损伤研究结果表明, 初相为π的信号更容易损伤器件, 而发射极串联电阻可以有效的提高器件的抗微波损伤能力.     

双极晶体管负载瞬态辐照毁伤效应

利用有源传输线模型与漂移-扩散模型的耦合计算模型,对在瞬态X射线辐照下电缆末端典型N+-p-n-N+结构的双极晶体管负载的毁伤效应与规律进行研究,通过分析双极晶体管内部晶格温度分布,判定是否处于毁伤状态,总结双极晶体管烧毁时间和烧毁所需能量与脉冲X射线脉冲宽度和注量之间的关系。结果表明:随着脉冲X射线脉宽增加,双极晶体管烧毁能量变化较小,烧毁时间逐渐增加;随着注量增加,烧毁时间逐渐降低,在5.86J/cm2以下时,烧毁所需能量基本相同,之后呈指数逐渐增加,并通过曲线拟合得到损伤规律的经验公式。     

不同剂量率下锗硅异质结双极晶体管电离损伤效应研究

对于相同制作工艺的NPN锗硅异质结双极晶体管(SiGe HBT), 在不同辐照剂量率下进行⁶⁰Co γ射线的辐照效应与退火特性的研究. 测量结果表明, 两种辐照剂量率下, 随着辐照总剂量增加, 晶体管基极电流增大, 共发射极电流放大倍数降低, 且器件的辐照损伤、性能退化与辐照剂量率相关, 低剂量率下辐照损伤较高剂量率严重. 在经过与低剂量率辐照等时的退火后, 高剂量率下的辐照损伤仍较低剂量率下的损伤低, 即待测SiGeHBT具有明显的低剂量率损伤增强效应(ELDRS). 本文对相关的物理机理进行了探讨分析. 关键词： 锗硅异质结双极晶体管 低剂量率辐照损伤增强 辐照效应     

Damage effect and mechanism of the GaAs pseudomorphic high electron mobility transistor induced by the electromagnetic pulse

The damage effect and mechanism of the electromagnetic pulse(EMP) on the GaAs pseudomorphic high electron mobility transistor(PHEMT) are investigated in this paper. By using the device simulation software, the distributions and variations of the electric field, the current density and the temperature are analyzed. The simulation results show that there are three physical effects, i.e., the forward-biased effect of the gate Schottky junction, the avalanche breakdown, and the thermal breakdown of the barrier layer, which influence the device current in the damage process. It is found that the damage position of the device changes with the amplitude of the step voltage pulse. The damage appears under the gate near the drain when the amplitude of the pulse is low, and it also occurs under the gate near the source when the amplitude is sufficiently high, which is consistent with the experimental results.     

Effects of microwave pulse-width damage on a bipolar transistor

This paper presents a theoretical study of the pulse-width effects on the damage process of a typical bipolar transistor caused by high power microwaves (HPMs) through the injection approach. The dependences of the microwave damage power, P, and the absorbed energy, E, required to cause the device failure on the pulse width τ are obtained in the nanosecond region by utilizing the curve fitting method. A comparison of the microwave pulse damage data and the existing dc pulse damage data for the same transistor is carried out. By means of a two-dimensional simulator, ISE-TCAD, the internal damage processes of the device caused by microwave voltage signals and dc pulse voltage signals are analyzed comparatively. The simulation results suggest that the temperature-rising positions of the device induced by the microwaves in the negative and positive half periods are different, while only one hot spot exists under the injection of dc pulses. The results demonstrate that the microwave damage power threshold and the absorbed energy must exceed the dc pulse power threshold and the absorbed energy, respectively. The dc pulse damage data may be useful as a lower bound for microwave pulse damage data.     

A silicon stress-sensitive unijunction transistor

The performance of a silicon stress-sensitive unijunction transistor is investigated. The transistor is classed as a stress-sensitive semiconductor lateral bipolar device with an S-type input (emitter) I-V characteristic. The optimal layout of the device and its basic parameters are determined. The device can serve as a basis for designing relaxation oscillators with the physically integrated function of mechanical stress-to-signal frequency conversion at the output.     

Control of the Interface Between Electron‐Hole and Electron‐Ion Plasmas: Hybrid Semiconductor‐Gas Phase Devices as a Gateway for Plasma Science

Coupling electron‐hole (e^–‐ h⁺) and electron‐ion plasmas across a narrow potential barrier with a strong electric field provides an interface between the two plasma genres and a pathway to electronic and photonic device functionality. The magnitude of the electric field present in the sheath of a low temperature, nonequilibrium microplasma is sufficient to influence the band structure of a semiconductor region in immediate proximity to the solid‐gas phase interface. Optoelectronic devices demonstrated by leveraging this interaction are described here. A hybrid microplasma/semiconductor photodetector, having a Si cathode in the form of an inverted square pyramid encompassing a neon microplasma, exhibits a photosensitivity in the ～420–1100 nm region as high as 3.5 A/W. Direct tunneling of electrons into the collector and the Auger neutralization of ions arriving at the Si surface appear to be facilitated by an n ‐type inversion layer at the cathode surface resulting from bandbending by the microplasma sheath electric field. Recently, an npn plasma bipolar junction transistor (PBJT), in which a low temperature plasma serves as the collector in an otherwise Si device, has also been demonstrated. Having a measured small signal current gain h_fe as large as 10, this phototransistor is capable of modulat‐ing and extinguishing the collector plasma with emitter‐base bias voltages <1 V. Electrons injected into the base when the emitter‐base junction is forward‐biased serve primarily to replace conduction band electrons lost to the collector plasma by secondary emission and ion‐enhanced field emission in which ions arriving at the base‐collector junction deform the electrostatic potential near the base surface, narrowing the potential barrier and thereby facilitating the tunneling of electrons into the collector. Of greatest significance, therefore, are the implications of active, plasma/solid state interfaces as a new frontier for plasma science. Specifically, the PBJT provides the first opportunity to control the electronic properties of a material at the boundary of, and interacting with, a plasma. By specifying the relative number densities of free (conduction band) and bound (valence band) electrons at the base‐collector interface, the PBJT's emitter‐base junction is able to dictate the rates of secondary electron emission (including Auger neutralization) at the semiconductor‐plasma interface, thereby offering the ability to vary at will the effective secondary electron emission coefficient for the base surface (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

中带电压法分离栅控横向pnp双极晶体管辐照感生缺

设计并制作了一种新型双极测试结构,即在常规横向pnp双极晶体管基区表面氧化层上淀积一栅电极,通过扫描栅极所加电压,获得漏极(集电极)电流随栅极电压的变化特性,利用中带电压法分离栅控横向pnp双极晶体管 在辐照过程中感生的氧化物陷阱电荷和界面陷阱电荷.本文对设计的晶体管测试结构和采用 的测试方法做了具体介绍.     

Fabrication and characterization of 4H—SiC bipolar junction transistor with double base epilayer

In this paper we report on a novel structure of a 4H-SiC bipolar junction transistor with a double base epilayer that is continuously grown.The measured dc common-emitter current gain is 16.8 at IC = 28.6 mA(J C = 183.4 A/cm2),and it increases with the collector current density increasing.The specific on-state resistance(Rsp-on) is32.3mΩ·cm 2 and the open-base breakdown voltage reaches 410 V.The emitter N-type specific contact resistance and N + emitter layer sheet resistance are 1.7×10-3 Ω·cm2 and 150 /,respectively.