毫米波GaN HEMT器件大信号模型

介绍了一种毫米波GaN基HEMT器件大信号等效电路模型。该模型采用SDD的建模方法。提出了I-V及C-V表达式,完成了直流及S参数的拟合,并分析了拟合结果。与18GHz的在片loadpull测试结果比较,模型仿真结果显示输出功率及效率与实测数据基本一致。     

一种HEMT器件可缩放的非线性紧凑模型

提供了一种应用于高电子迁移率晶体管(HEMT)的非线性紧凑模型。该模型针对传统的EE-HEMT模型理想缩放规律不准确的问题,提出采用一元函数拟合、二元曲面拟合方法,对其尺寸缩放和温度缩放规律进行修正。修正后的非线性模型可以准确地模拟HEMT器件的直流I-U、S参数和大信号特性。并将该模型应用于一款0.25 μm栅长的GaAs pHEMT工艺,对比不同尺寸的器件在高低温条件下模型仿真结果和实测结果,两者吻合良好,验证了该模型的准确性。     

采用75 nm InP HEMT开发的20 Gb/s短脉冲发生器

据《信学技报》(日)2010年109-361期报道,日本富士通株式会社采用了为了降低寄生电容而使栅电极周边空洞化(Cavity)的栅长为75 nm的InP HEMT器件,成功开发了传输速度超过10 Gb/s的短脉冲发生器。InP HEMT器件的g_m为2 S/mm,f_T为390 GHz,f_(max)为490 GHz。测试结果,该发生器成功地生成了20Gb/s以上的随机性脉冲。这次开发的短脉冲发生器除应用于无线通信,还可应用于高频(超过100 GHz)检测仪器和超高分辨力雷达等各种宽带系统。     

一种鱼骨型GaN HEMT分布式模型

基于传输线理论,推导了GaN HEMT沟道分布式等效电路模型,为有效提取GaN HEMT小信号模型参数提供了依据。设计了一种新颖的鱼骨型GaN HEMT器件结构,由于采用了较短的栅指,非常有利于纵向散热,与常规型HEMT器件结构相比,热阻有了明显改善,但也增加了建模的复杂度。采用分布式建模技术,为鱼骨型器件建立了一种分布式等效电路模型,模型在1~20 GHz内与实测S参数吻合较好,表明分布式建模技术可以用于准确地模拟鱼骨型GaN HEMT器件的高频特性。     

3 mm 波段低噪声放大器

基于InP HEMT在3 mm波段的优越的噪声性能,设计制作了一款3 mm波段InP HEMT低噪声放大器。通过合理设计外延材料结构和器件结构,提高器件性能。测试1~40 GHz器件的S参数和噪声参数以及75~110 GHz器件的S参数,并采用外推的方法建立了器件的噪声模型。电路设计采用ADS仿真软件,采用全版图电磁场仿真保证电路设计的准确性,最终实现了一款3 mm波段低噪声放大器。测试结果显示在92~96 GHz时,带内增益大于20 dB,噪声系数小于4.0 dB。芯片面积3.07 mm×1.75 mm,直流功耗60 mW。     

基于50nm AlN/GaN异质结的G波段放大器

报道了基于50 nm栅工艺的AlN/GaN异质结的G波段器件结果。在AlN/GaN HEMT外延结构上,采用电子束直写工艺制备了栅长50 nm的"T"型栅结构。器件直流测试最大漏电流为2.1 A/mm,最大跨导为700 mS/mm;小信号测试外推其电流增益截止频率和最大振荡频率分别为180 GHz及350 GHz。采用该工艺制备的共面波导(CPW)结构的放大器工作电压6 V,在162 GHz小信号增益大于10 dB。166 GHz连续波峰值输出功率11.36 dBm,功率密度达到684 mW/mm,功率密度水平达到GaN器件在G频段的高水平。     

双层InGaAs沟道InP HEMT

阐述了一种新型的In0.80Ga0.02As／In0.053。Ga0.47 As双沟道InP HEMT结构。采用这种双沟道结构能够有效地提高沟道中电子的迁移率，减小碰撞电离对HEMT性能的影响;从而既显著提高了HEMT的截止频率，又可获得很高的直流输出电流．0．35μ栅长HEMT器件的电流增益截止频率达到120GHz,饱和电流密度、跨导达到790mA/mm、1 050mS／mm,栅极击穿电压和通态击穿电压分别为5V和3．2V。     

一种改进的增强型GaN HEMT大信号模型

提出一种改进的增强型GaN HEMT器件建模大信号模型.模型沟道电流方程和电荷方程均连续且高阶可导,栅电荷模型满足电荷守恒原则.提出的沟道电流模型可精确拟合实际器件正、反向区、截止区以及亚阈值区的直流特性.根据GaN HEMT器件特有的物理结构和电学特性,器件的自热效应、电流崩塌效应以及跨导频率分布效应在模型中进行了考虑.模型采用Verilog-A语言进行描述,并编译、链接入Agilent ADS工具.验证结果表明,模型仿真和测试数据在宽的偏压和频率范围内得到很好地吻合.     

一种InP HEMT分布小信号模型建模方法

提出了一种用于InP高电子迁移率晶体管（high electron mobility transistor,HEMT）的分布式小信号等效电路建模方法。在采用的模型中考虑了分布电容效应,通过加入三个分布电容来表征。为了精确建模,在提取寄生电容时考虑到寄生电感引入的误差,首先提取了寄生电感。在达到50 GHz的InP HEMT中,小信号建模方法的有效性得到了验证。此外,在2～50 GHz频率范围内,S参数建模误差小于4%,这也证明了所提出建模方法的高建模精度。     

AlGaN/GaN HEMT小信号模型参数提取算法

本文采用了新型的22元件AlGaN/GaN HEMT小信号等效电路模型,较传统的模型,增加了栅漏电导Ggdf和栅源电导Ggsf来表征GaN HEMT的栅极泄漏电流。同时针对新型的栅场板、源场板结构器件,提出了一种改进的寄生电容参数提取方法,使之适用于提取非对称器件的小信号模型参数。为验证此模型,获得了S参数的测试结果和模型仿真结果,此二者的吻合度较高,表明新型的22元件小信号模型精确、稳定而且物理意义明确。     

Ultra-short 25-nm-gate lattice-matched InAlAs/InGaAs HEMTs withinthe range of 400 GHz cutoff frequency

We have succeeded in fabricating ultra-short 25-nm-gate InAlAs/InGaAs high electron mobility transistors (HEMTs) lattice-matched to InP substrates. The two-step-recessed gate technology and low temperature processing at below 300°C allowed the fabrication of such ultra-short gates. DC measurements showed that the 25-nm-gate HEMT had good pinchoff behavior. We obtained a cutoff frequency f_T of 396 GHz, within the range of 400 GHz f_T, for the 25-nm-gate HEMT. This f_T is the highest value get reported for any type of transistor, and the gate length of 25 nm is the shortest value ever reported for any compound semiconductor transistor that exhibits device operation     

栅长90nm的晶格匹配InAlAs／InGaAs／InP HEMT

文章报道了90nm栅长的晶格匹配InP基HEMT器件。栅图形是通过80kV的电子束直写的,并采用了优化的三层胶工艺。器件做在匹配的InAlAs／InGaAs／InP HEMT材料上。当Vds=1．0V时,两指75μm栅宽器件的本征峰值跨导达到720ms／mm,最大电流密度为500mA／mm,器件的阂值电压为．0．8V,截止频率达到127GHz,最大振荡频率达到152GHz。     

A novel InGaAs/InAlAs insulated gate pseudomorphic HEMT with asilicon interface control layer showing high DC- and RF-performance

A novel InGaAs/InAlAs insulated gate pseudomorphic HEMT (IG-PHEMT) utilizing a silicon interface control layer (Si ICL) was successfully fabricated and its DC and RF performances were characterized. The device showed high transconductance of 177 mS/mm even for a gate length of 1.6 μm. As compared with the conventional Schottky gate PHEMTs, the gate leakage current was reduced by 4 orders of magnitudes and the gate breakdown voltage was increased up to 39 V. Well-behaved RF characteristics with the current gain cutoff frequency, f_T, of 9 GHz and the maximum oscillation frequency, f_max, of 38 GHz were obtained for the 1.6 μm-gate-length device     

A high-performance enhancement-mode AlGaN/GaN HEMT

An enhancement-mode AlGaN/GaN HEMT with a threshold voltage of 0.35 V was fabricated by fluorine plasma treatment.The enhancement-mode device demonstrates high-performance DC characteristics with a saturation current density of 667 mA/mm at a gate bias of 4 V and a peak transconductance of 201 mS/mm at a gate bias of 0.8 V.The current-gain cut-off frequency and the maximum oscillation frequency of the enhancement-mode device with a gate length of μm are 10.3 GHz and 12.5 GHz,respectively,which is comparable with the depletion-mode device.A numerical simulation supported by SIMS results was employed to give a reasonable explanation that the fluorine ions act as an acceptor trap center in the barrier layer.     

An improved large signal model of InP HEMTs

An improved large signal model for InP HEMTs is proposed in this paper.The channel current and charge model equations are constructed based on the Angelov model equations.Both the equations for channel current and gate charge models were all continuous and high order drivable,and the proposed gate charge model satisfied the charge conservation.For the strong leakage induced barrier reduction effect of InP HEMTs,the Angelov current model equations are improved.The channel current model could fit DC performance of devices.A 2 × 25μm × 70 nm InP HEMT device is used to demonstrate the extraction and validation of the model,in which the model has predicted the DC I-V,C-Vand bias related S parameters accurately.     

An analytical parasitic resistance dependent Id–Vd model for planar doped InAlAs/InGaAs/InP HEMT using non-linear charge control analysis

An analytical parasitic resistance dependent model for the current voltage characteristics for InAlAs/InGaAs/InP HEMT is proposed. The model uses a new polynomial dependence of sheet carrier concentration on gate voltage to calculate I_d–V_d characteristics and has been extended to obtain transconductance, output conductance and cut-off frequency of the device. A maximum cut-off frequency of 83 and 175 GHz was obtained for channel length of 0.25 and 0.1 μm, respectively. Close agreement with published results confirms the validity of our approach.     

锯齿型源漏结构的新型InP基HEMT器件

毫米波晶体管的制作技术是微波电路设计和制造的基础.从优化器件结构的角度,提出了一种锯齿型源漏的新型InP基HEMT器件.实验证明,采用这种结构可以减少光刻过程中临近效应的影响,改善源漏的图形形貌,提高器件制做的成品率.获得了具有良好直流和微波特性的晶体管,其跨导达到1050mS/mm,阈值电压为-1.0V,截止频率达到120GHz.     

Very high efficiency V-band power InP HEMT MMICs

State-of-the-art power performance of a V-band InP HEMT MMIC is reported using a slot via process for reducing source inductance and a fully selective gate recess process for uniformity and high yield. The 0.1 μm gate length, high performance InGaAs/InAlAs/InP HEMTs that were utilized in the circuit exhibited a maximum power density of 530 mW/mm, power added efficiency of 39%, and a gain of 7.1 dB. At 60 GHz, a single-stage monolithic power amplifier achieved an output power of 224 mW with a PAE of 43%. The associated gain was 7.5 dB. These results are the best combination of output power and efficiency reported for an InP device and a MMIC at V-band, and clearly demonstrates the potential of the InP HEMT technology for very high efficiency, millimeter wave power applications     

A High Performance InP HEMT with Saw-Toothed Source and Drain

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InP HEMT downscaling for power applications at W band

We have developed new solutions for InP high-electron mobility transistor (HEMT) scaling for power applications at W band. We have shown that the use of a small barrier thickness in order to respect the aspect ratio for a 70-nm gate length results in a significant kink effect and high gate source capacitances. We have also shown through a theoretical study that a structure containing an InP layer between the cap layer and the barrier would support both the frequency performances and the breakdown voltage. Thus, we propose an HEMT structure containing a thick InP/AlInAs composite barrier and where the gate is buried into the barrier. This enables us to respect the aspect ratio and simultaneously to obtain an important drain current density without observing any kink effect. Moreover, we have applied this process to structures containing innovative large band-gap InP and InAsP channels. We have achieved the best frequency performances ever reached for an InP channel HEMT structure. Power measurements at 94 GHz were performed on these devices. The InAsP channel HEMT demonstrated a maximum output power of 260 mW/mm at 3 V of drain voltage with 5.9-dB power gain and a power-added efficiency of 11%. These results are favorably comparable to the state-of-the-art of InP-based HEMT at this frequency.