InAlAs/InGaAs PHEMTs的设计及其110GHz全频段小信号建模

90-nm T-shaped gate InP-based In_0.52Al_0.48As/In_0.6Ga_0.4As pseudomorphic high electron mobility transistors were designed and fabricated with a gate-width of 2×30 μm,a source-drain space of 2.5 μm,and a source-gate space of 0.75 μm.DC,RF and small-signal model characterizations were demonstrated.The maximum saturation current density was measured to be 755 mA/mm biased at V_gs=0.6 V and V_ds=1.5 V.The maximum extrinsic transconductance was measured to be 1006 mS/mm biased at V_ds=—0.1V and V_ds=1.5 V.The extrapolated current gain cutoff frequency and maximum oscillation frequency based on S-parameters measured from 0.5 to 110 GHz were 180 and 264 GHz,respectively.The inflection point（the stability factor k=1）where the slope from-10 dB/decade（MSG） to-20 dB/decade（MAG） was measured to be 83 GHz.The smallsignal model of this device was also established,and the S-parameters of the model are consistent with those measured from 0.5-110 GHz.     

MBE生长的高质量AlGaAs/InGaAs双δ掺杂PHEMT结构的材料

用 MBE方法制备的 PHEMT微结构材料 ,其 2 DEG浓度随材料结构的不同在 2 .0— 4.0× 1 0 12 cm- 2 之间 ,室温霍耳迁移率在 50 0 0— 650 0 cm2 · V- 1· s- 1之间 .制备的 PHEMT器件 ,栅长为 0 .7μm的器件的直流特性 :Idss～ 2 80 m A/mm,Imax～ 52 0— 580 m A/mm,gm～ 32 0— 40 0 m S/mm,BVDS>1 5V( IDS=1 m A/mm) ,BVGS>1 0 V,微波特性 :P0 ～ 60 0— 90 0 m W/mm,G～ 6— 1 0 d B,ηadd～ 40— 60 % ;栅长为 0 .4μm的器件的直流特性 :Imax～ 80 0 m A/mm,gm>40 0 m S/mm.     

增强型InGaP/AlGaAs/InGaAs PHEMT栅退火工艺

针对InGaP/AlGaAs/lnGaAs PHEMT器件,进行了Ti/Pt/Au和Pt/Ti/Pt/Au两种栅金属结构的退火实验,通过实验研究比较,得到了更适用于增强型器件的退火工艺,利用Ti/Pt/Au结构,在320℃退火40min,使器件阈值电压正向移动大约200mV,从而成功制作了高成品率的稳定一致的增强型器件,保证了增强型器件阈值电压在零以上.     

增强型InGaP/AlGaAs/InGaAs PHEMT小信号等效电路参数的提取

介绍了增强型InGaP/AlGaAs/InGaAs PHEMT小信号等效电路中元件参数值的提取方法,并利用IC-CAP软件EEHEMT1模型提取了参数.利用ADS软件验证了提参结果,ADS仿真的直流I-V曲线和S参数与实测结果基本吻合.结果表明EEHEMT1模型可以用于提取增强型PHEMT参数,并且具有可操作性.     

Monolithic Integration of InGaP/AlGaAs/InGaAs Enhancement/Depletion-Mode PHEMTs

提出了一种新结构单片集成增强/耗尽型(E/D)InGaP/AlGaAs/InGaAs赝配高电子迁移率晶体管(PHEMTs).外延层材料通过分子束外延技术生长,在室温下,其电子迁移率和二维电子气浓度分别为5410cm2/(V·s)和1.34×1012cm-2.首次提出了普通光学接触曝光分步制作增强与耗尽型的栅技术方法.研制出了单片集成E/D型PHEMTs,获得良好的直流和交流特性,最大饱和漏电流密度分别为300和340mA/mm,跨导为350和300mS/mm,阈值电压为0.2和-0.4V,增强型的fT和fmax为10.3和12.4GHz,耗尽型的fT和fmax为12.8和14.7GHz.增强/耗尽型PHEMTs的栅漏反向击穿电压都为-14V.     

As元素分子态对InGaAs/AlGaAs量子阱红外探测器性能的影响

对As2和As4两种不同分子态下利用分子束外延技术(MBE)生长的单层AlGaAs薄膜和GaAs基InGaAs/AlGaAs量子阱红外探测器(QWIP)的性能进行了研究,发现As2条件下生长的单层AlGaAs材料荧光强度更大、深能级缺陷密度更低;相对于As4较为复杂的吸附、生长机制引入的缺陷,在As2条件下生长的InGaAs/AlGaAs QWIP具有更低的暗电流密度、更好的黑体响应、更高的比探测率和更优异的器件均匀性。生长制备的InGaAs/AlGaAs QWIP在60K的工作温度、-2V偏压下,暗电流密度低至7.8nA/cm2,光谱响应峰值波长为3.59μm,4V偏压下峰值探测率达到1.7×1011 cm·Hz1/2·W-1。另外,通过As元素的不同分子态下InGaAs/AlGaAs QWIP光响应谱峰位的移动可以推断出As元素的不同分子态也会影响In的并入速率。     

基于红外测温的GaN HEMT器件结构函数法热阻测量

为了准确的测量GaN HEMT的热阻参数,在两种不同的管壳接触热阻条件下,利用经过改进的显微红外热像仪测量了GaN HEMT的降温曲线。采用结构函数算法对两种降温曲线进行分析,得到了反映器件各层材料热阻的积分结构函数曲线。当管壳接触层由空气变化为导热硅脂时,积分结构函数曲线发生了变化。通过结构函数曲线能够明确区分被测件不同层的热阻。可以将被测件的分成6层结构,与器件真实结构基本一致。     

GaAs MESFET的漏源电压对旁栅阈值电压的影响

研究了改变ＭＥＳＦＥＴ漏源电压大小和交流源漏电极对旁栅阈值电压的影响,并从理论上解释了与高场下衬底深能级ＥＬ２的碰撞电离关系。     

InAlAs/InGaAs/InP基PHEMTs小信号建模及低噪声应用

利用改进的小信号模型对采用100nmInAlAs/InGaAs/InP工艺设计实现的PHEMTs器件进行建模, 并设计实现了一款W波段单片低噪声放大器进行信号模型的验证。为了进一步改善信号模型低频S参数拟合差的精度, 该小信号模型考虑了栅源和栅漏二极管微分电阻, 在等效电路拓扑中分别用Rfs和Rfd表示.为了验证模型的可行性, 基于该信号模型研制了W波段低噪声放大器单片.在片测试结果表明:最大小信号增益为14.4dB@92.5GHz, 3dB带宽为25GHz@85-110GHz.而且, 该放大器也表现出了良好的噪声特性, 在88GHz处噪声系数为4.1dB, 相关增益为13.8dB.与同频段其他芯片相比, 该放大器单片具有宽3dB带宽和高的单级增益.     

增强型InGaP/AlGaAs/InGaAs PHEMT小信号等效电路参数的提取

介绍了增强型InGaP／AlGaAs／InGaAs PHEMT小信号等效电路中元件参数值的提取方法，并利用IC-CAP软件EEHEMT1模型提取了参数．利用ADS软件验证了提参结果，ADS仿真的直流I-V曲线和S参数与实测结果基本吻合．结果表明EEHEMT1模型可以用于提取增强型PHEMT参数，并且具有可操作性．     

Evaluation of the drain-source voltage effect on AIGaAs/InGaAs PHEMTs thermal resistance by the structure function method

The effect of drain-source voltage on A1GaAs/InGaAs PHEMTs thermal resistance is studied by experimental measuring and simulation. The result shows that A1GaAs/InGaAs PHEMTs thermal resistance presents a downward trend under the same power dissipation when the drain-source voltage （VDs） is decreased. Moreover, the relatively low VDS and large drain-source current （IDs） result in a lower thermal resistance. The chip-level and package-level thermal resistance have been extracted by the structure function method. The simulation result indicated that the high electric field occurs at the gate contact where the temperature rise occurs. A relatively low VDS leads to a relatively low electric field, which leads to the decline of the thermal resistance.     

Power improvement of AlGaAs/InGaAs PHEMTs by using low gamma radiation dose

This paper shows the possibility to improve DC and RF electrical performances of AlGaAs/InGaAs PHEMTs by using low gamma radiation dose. The drain-source saturation current and the DC transconductance increase when the devices are irradiated with a gamma dose of 42.8 krad(GaAs) and then remain constant up to 0.85 Mrad(GaAs). This improvement is attributed to a reduction of access resistances. In the same time, the Schottky diode and the current-gain cut-off frequency of these components are not degraded by the gamma irradiation. Moreover, the maximum output power density is improved by 18%. This paper demonstrates that it is possible to improve the component electrical performances by using an original method.     

太赫兹InP基InAlAs/InGaAs PHEMTs的研制

研制了一种T型栅长为90 nm的InP基In0.52Al0.48As/In0.65Ga0.35As赝配高电子迁移率晶体管(PHEMTs).该器件的总栅宽为2×25 μm,展现了极好的DC直流和RF射频特性,其最大饱和电流密度和最大有效跨导分别为894 mA/mm和1640 mS/mm.采用LRM+ (Line-Reflect-Reflect -Match)校准方法实现系统在1~110 GHz全频段内一次性校准,减小了传统的分段测试多次校准带来的误差, 且测试数据的连续性较好.在国内完成了器件的1~110 GHz全频段在片测试,基于1~110 GHz在片测试的S参数外推获得的截止频率ft和最大振荡频率fmax分别为252 GHz和394 GHz.与传统的测试到40 GHz外推相比,本文外推获得的fmax更加准确.这些结果的获得是由于栅长的缩短,寄生效应的减小以及1~110 GHz全频段在片测试的实现.器件的欧姆接触电阻率减小为0.035 Ω·mm.     

Current-voltage behavior of AlGaAs/InGaAs pHEMT structures and the effect of optical illumination

Various pseudomorphic High Electron Mobility Transistor (pHEMT) structures of AlGaAs/InGaAs alloys have been observed their current-voltage behavior. The tungsten probes were used for a measurement the structures by ramping the voltage from −5 to 5 V and measure the electrical current. Measurement was carried out at room temperature and also under optical illumination. From the measurement, the electrical current was found to increase as the increase of Al content in the AlGaAs alloys layer in the pHEMT structure. This phenomenon was supported by the decrease of sheet resistance as obtained from Hall effect measurement. Under visible light illumination, the current-voltage behavior of pHEMT structure was observed to vary as the light power density was varied for 0, 25 and 55 μW/cm.     

InGaAs/AlGaAs量子阱中量子尺寸效应对PL谱的影响

本文采用金属有机物化学气相淀积(MOCVD)方法设计并生长了两组InGaAs／A1GaAs应变多量子阱，量子阱的厚度分别为3nm和6nm，对其光致发光谱(PL)进行了研究，二者的发光波长分别为843nm和942nm，用有限深单量子阱理论近似计算了由于量子尺寸效应和应变效应引起的InGaAs／A1GaAs量子阱带隙的改变，这解释了两组样品室温下PL发射波长变化的原因。     

Detection of lead ions with AlGaAs/InGaAs pseudomorphic high electron mobility transistor

Lead poisoning is a serious environmental concern, which is a health threat. Existing technologies always have some drawbacks, which restrict their application ranges, such as real time monitoring. To solve this problem, glutathione was functionalized on the Au-coated gate area of the pseudomorphic high electron mobility transistor (pHEMT) to detect trace amounts of Pb²⁺. The positive charge of lead ions will cause a positive potential on the Au gate of the pHEMT sensor, which will increase the current between the source and the drain. The response range for Pb²⁺ detection has been determined in the concentrations from 0.1 pmol/L to 10 pmol/L. To our knowledge, this is currently the best result for detecting lead ions.     

Effects of hot-electron stress on electrical performances in AlGaAs/InGaAs pseudomorphic high electron transistors

The effects of hot-electron stress on electrical properties in AlGaAs/InGaAs pseudomorphic high electron mobility transistors were investigated using current-voltage (I–V), capacitance-voltage (C-V), deep level transient spectroscopy (DLTS), and transconductance dispersion measurements. After hot-electron stress, the three-terminal gate-drain breakdown characteristics were improved and the gate-drain capacitance was decreased even though no difference was found in both DLTS and transconductance dispersion results. These results suggest that hot electrons were trapped at the interface of the passivation layer, Si₃N₄, with AlGaAs, locating between gate and source/drain electrodes, leading to the increase of the depletion region under the ungated region. On the other hand, the two-terminal gate-drain breakdown characteristics were deteriorated by hot-electron stress. This was due to the reduction of the Schottky barrier height.     

Ka波段AlGaAs/InGaAs低噪声PHEMT异质材料结构的计算机优化与实验结果

讨论了毫米波低噪声ＰＨＥＭＴ的设计要点，藕助Ｓｃｈｒｏｅｄｉｎｇｅｒ／Ｐｏｉｓｓｏｎ方程及器件方程，进行了Ｋａ波段ＡｌＧａ／ＩｎＧａＡｓ低噪声ＰＨＥＭＴ用异质层数值计算及ＣＡＤ优化，确定出分子束外延ＭＢＥ时诸层的最佳组分、浓度、与厚度、上述优化分析的结果用于器件的实验研制，取得了３４．４ＧＨｚ下噪声系数（ＮＦ）１．９２ｄＢ、相关增益Ｇａ６．５ｄＢ的国内最好结果。