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.     

GaAs基单片集成InGaP／AIGaAs／InGaAs增强／耗尽型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.     

单片集成0.8μm栅长GaAs基InGaP/AlGaAs/InGaAs增强/耗尽型赝配高电子迁移率晶体管

优化了GaAs基InGaP/AlGaAs/InGaAs赝配高电子迁移率晶体管(PHEMT)的外延结构,有利于获得增强型PHEMT的正向阈值电压.采用光学接触式光刻方式,实现了单片集成0.8μm栅长GaAs基InGaP/AlGaAs/InGaAs增强/耗尽型PHEMT.直流和高频测试结果显示:增强型(耗尽型)PHEMT的阈值电压、非本征跨导、最大饱和漏电流密度、电流增益截止频率、最高振荡频率分别为0.1V(-0.5V),330mS/mm(260mS/mm),245mA/mm(255mA/mm),14.9GHz(14.5GHz)和18GHz(20GHz).利用单片集成增强/耗尽型PHEMT实现了直接耦合场效应晶体管逻辑反相器,电源电压为1V,输入0.15V电压时,输出电压为0.98V;输入0.3V电压时,输出电压为0.18V.     

单片集成0.8μm栅长GaAs基InGaP/AlGaAs/InGaAs增强/耗尽型赝配高电子迁移率晶体管

优化了GaAs基InGaP/AlGaAs/InGaAs赝配高电子迁移率晶体管(PHEMT)的外延结构,有利于获得增强型PHEMT的正向阈值电压.采用光学接触式光刻方式,实现了单片集成0.8μm栅长GaAs基InGaP/AlGaAs/InGaAs增强/耗尽型PHEMT.直流和高频测试结果显示:增强型(耗尽型)PHEMT的阈值电压、非本征跨导、最大饱和漏电流密度、电流增益截止频率、最高振荡频率分别为0.1V(-0.5V),330mS/mm(260mS/mm),245mA/mm(255mA/mm),14.9GHz(14.5GHz)和18GHz(20GHz).利用单片集成增强/耗尽型PHEMT实现了直接耦合场效应晶体管逻辑反相器,电源电压为1V,输入0.15V电压时,输出电压为0.98V;输入0.3V电压时,输出电压为0.18V.     

最大振荡频率640 GHz的70 nm栅长InAs PHEMTs器件

由于高的电子迁移率和二维电子气浓度,InP基赝配高电子迁移率晶体管（PHEMTs）器件成为制作太赫兹器件最有前途的三端器件之一。为提高器件的工作频率,采用InAs复合沟道,使得二维电子气的电子迁移率达到13000 cm2/（Vs）。成功研制出70 nm栅长的InP基赝配高电子迁移率晶体管,器件采用双指,总栅宽为30 m,源漏间距为2 m。为降低器件的寄生电容,设计T型栅的栅根高度达到210 nm。器件的最大漏端电流为1440 mA/mm （VGS=0.4 V）,最大峰值跨导为2230 mS/mm。截止频率fT和最大振荡频率fmax分别为280 GHz和640 GHz。这些性能显示该器件适于毫米波和太赫兹波应用。     

fT为102 GHz的蓝宝石衬底AlGaN/GaN高电子迁移率晶体管

研究了一款高性能的AlGaN/GaN高电子迁移率晶体管器件(HEMT),器件基于在蓝宝石衬底上外延生长的AlGaN/GaN异质结构HEMT材料,器件栅长为86 nm,源漏间距为0.8μm。电子束光刻实现T型栅和源漏,保证了器件小的栅长和高的对准精度。制备的器件显示了良好的直流特性和射频特性,在栅偏压为0 V时漏电流密度为995 mA/mm,在栅源电压Vgs为-4.5 V时,最大峰值跨导为225 mS/mm;器件的电流增益截止频率fT和最大振荡频率fmax分别为102和147 GHz。高fT值一方面得益于小栅长,另一方面由于小源漏间距减小了源漏沟道电阻。     

SiC衬底上栅长70 nm fT / fmax >160 GHz的InAlN/GaN HEMTs器件

在SiC衬底上制备了InAlN/GaN 高电子迁移率晶体管（HEMTs）,并进行了表征。为提高器件性能,综合采用了多种技术,包括高电子浓度,70 nm T型栅,小的欧姆接触电阻和小源漏间距。制备的InAlN/GaN器件在栅偏压为1 V时得到的最大饱和漏电流密度为1.65 A/mm,最大峰值跨导为382 mS/mm。70 nm栅长器件的电流增益截止频率fT和最大振荡频率fmax分别为162 GHz和176 GHz。     

最大振荡频率为200 GHz的蓝宝石衬底AlGaN/GaN HEMT

本文报道了fmax为200GHz的基于蓝宝石衬底的AlGaN/GaN 高电子迁移率晶体管（HEMT）。外延材料结构采用了InGaN背势垒层来减小短沟道效应,器件采用了凹栅槽和T型栅结合的工艺,实现了Ka波段AlGaN/GaN HEMT。器件饱和电流达到1.1A/mm,跨导为421mS/mm,截止频率（fT）为30GHz,最大振荡频率（fmax）为105GHz。采用了湿法腐蚀工艺将器件的Si3N4钝化层去除后,器件的Cgs和Cgd减小,器件截止频率提高到50GHz,最大振荡频率提高到200GHz。     

1.0μm栅长GaAs基MHEMT器件及SPDT开关MMIC

利用MBE外延材料和接触式光学光刻方式,成功制备出1.0μm栅长GaAs基MHEMT器件,分别蒸发Pt/Ti/Pt/Au和Ti/Pt/Au作为栅电极金属.获得了优越的DC和RF性能,Pt/Ti/Pt/Au和Ti/Pt/Au MHEMT器件的gm为502(503)mS/mm,JDss为382(530)mA/mm,VT为0.1(-0.5)V,fT和fmax分别为13.4(14.8),17.0(17.5)GHz.利用单片集成增强/耗尽型GaAs基MHEMT器件制备出九阶环型振荡器,直流电压为1.2V时,振荡频率达到777.6MHz,门延迟时间为71.4ps.利用Ti/Pt/Au MHEMT器件设计并制备出了DC-100Hz单刀双掷(SPDT)关MMIC,其插入损耗、隔离度、输入输出回波损耗分别优于2.93,23.34和20dB.     

1.0μm栅长GaAs基MHEMT器件及SPDT开关MMIC

利用MBE外延材料和接触式光学光刻方式,成功制备出1.0μm栅长GaAs基MHEMT器件,分别蒸发Pt/Ti/Pt/Au和Ti/Pt/Au作为栅电极金属.获得了优越的DC和RF性能,Pt/Ti/Pt/Au和Ti/Pt/Au MHEMT器件的gm为502(503)mS/mm,JDss为382(530)mA/mm,VT为0.1(-0.5)V,fT和fmax分别为13.4(14.8),17.0(17.5)GHz.利用单片集成增强/耗尽型GaAs基MHEMT器件制备出九阶环型振荡器,直流电压为1.2V时,振荡频率达到777.6MHz,门延迟时间为71.4ps.利用Ti/Pt/Au MHEMT器件设计并制备出了DC-100Hz单刀双掷(SPDT)关MMIC,其插入损耗、隔离度、输入输出回波损耗分别优于2.93,23.34和20dB.     

单片集成GaAs增强／耗尽型赝配高电子迁移率晶体管

介绍了单片集成GaAs增强／耗尽型赝配高电子迁移率晶体管（PHEMT）工艺。借助栅金属的热处理过程,形成了热稳定性良好的Pt／Ti／Pt／Au栅。AFM照片结果表明Pt金属膜表面非常平整,2nm厚度膜的粗糙度RMS仅为0．172nm。通过实验,我们还得出第一层Pt金属膜的厚度和退火后的下沉深度比大概为1：2。制作的增强型／耗尽型PHEMT的闽值电压（定义于1mA／mm）、最大跨导、最大饱和漏电流密度、电流增益截止频率分别是＋0．185／-1．22V、381．2／317．5mS／mm、275／480mA／mm、38／34GHz。增强型器件在4英寸圆片上的阈值电压标准差为19mV。     

fmax为100GHz的蓝宝石衬底AlGaN/GaN高电子迁移率晶体管

制作了蓝宝石衬底上生长的AlGaN/GaN高电子迁移率晶体管.0V栅压下,0.3μm栅长、100μm栅宽的器件的饱和漏电流密度为0.85A/mm,峰值跨导为225mS/mm;特征频率和最高振荡频率分别为45和100GHz;4GHz频率下输出功率密度和增益分别为1.8W/mm和9.5dB,8GHz频率下输出功率密度和增益分别为1.12W/mm和11.5dB.     

Super low noise InGaP gated PHEMT

Very high performance InGaP/InGaAs/GaAs PHEMTs will be demonstrated. The fabricated InGaP gated PHEMTs devices with 0.25 × 160/cm² and 0.25 × 300 μm² of gate dimensions show 304 mA/mm and 330 mA/mm of saturation drain current at V_GS = 0 V, V_DS = 2 V, and 320 mS/mm and 302 mS/mm of extrinsic transconductances, respectively. Noise figures for 160 μm and 300 μm gate-width devices at 12 GHz are measured to be 0.46 dB with a 13 dB associated gain and 0.49 dB with a 12.85 dB associated gain, respectively. With such a high gain and low noise, the drain-to-gate breakdown voltage can be larger than 11 V. Standard deviation in the threshold voltage of 22 mV for 160 μm gate-width devices across a 4-in wafer can be achieved using a highly selective wet recess etching process. Good thermal stability of these InGaP gated PHEMTs is also presented     

High performance 0.35 μm gate-length monolithicenhancement/depletion-mode metamorphicIn0.52Al0.48As/In0.53Ga0.47As HEMTs on GaAs substrates

Monolithic integration of enhancement (E)- and depletion (D)-mode metamorphic In_0.52Al_0.48As/In_0.53Ga_0.47 As/GaAs HEMTs with 0.35 μm gate-length is presented for the first time. Epilayers are grown on 3-inch SI GaAs substrates using molecular beam epitaxy. A mobility of 9550 cm²/V-s and a sheet density of 1.12×10^{12 -2} are achieved at room temperature. Buried Pt-gate was employed for E-mode devices to achieve a positive shift in the threshold voltage. Excellent characteristics are achieved with threshold voltage, maximum drain current, and extrinsic transconductance of 100 mV, 370 mA/mm and 660 mS/mm, respectively for E-mode devices, and -550 mV, 390 mA/mm and 510 mS/mm, respectively for D-mode devices. The unity current gain cutoff frequencies of 75 GHz for E-mode and 80 GHz for D-mode are reported     

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     

输出功率密度为2.23W/mm的X波段AlGaN/GaN功率HEMT器件

MOCVD技术在蓝宝石衬底上制备出具有高迁移率GaN沟道层的AlGaN/GaN HEMT材料.高迁移率GaN外延层的室温迁移率达741cm2/(V·s),相应背景电子浓度为1.52×1016cm-3;非有意掺杂高阻GaN缓冲层的室温电阻率超过108Ω·cm,相应的方块电阻超过1012Ω/□.50mm HEMT外延片平均方块电阻为440.9Ω/□,方块电阻均匀性优于96％.用此材料研制出了0.2μm栅长的X波段HEMT功率器件,40μm栅宽的器件跨导达到250mS/mm,特征频率fT为77GHz;0.8mm栅宽的器件电流密度达到1.07A/mm,8GHz时连续波输出功率为1.78W,相应功率密度为2.23W/mm,线性功率增益为13.3dB.     

A high-current pseudomorphic AlGaAs/InGaAs double quantum-wellMODFET

Double quantum-well modulation-doped field-effect transistors (MODFETs) with planar-doped lattice-strained AlGaAs/InGaAs structure have been fabricated and characterized at DC and microwave frequencies. At 300 K the 0.3-μm gate devices show a full channel current of 1100 mA/mm with a constant extrinsic transconductance of 350 mS/mm over a broad gate voltage range of 1.6 V. Excellent microwave performance is also achieved with a maximum available gain cutoff frequency f _mag of 110 GHz and a current gain cutoff frequency f _r of 52 GHz. A maximum output power of 0.7 W/mm with 30% efficiency is obtained at 18 GHz     

Fabrication and characterization of AlGaN/GaN HEMTs with high power gain and efficiency at 8 GHz

State-of-the-art AlGaN/GaN high electron mobility structures were grown on semi-insulating 4H-SiC substrates by MOCVD and X-band microwave power high electron mobility transistors were fabricated and characterized.Hall mobility of 2291.1 cm2/(V·s) and two-dimensional electron gas density of 9.954 × 1012 cm-2 were achieved at 300 K.The HEMT devices with a 0.45-μm gate length exhibited maximum drain current density as high as 1039.6 mA/mm and peak extrinsic transconduct-ance of 229.7 mS/mm.The fT of 30.89 GHz and fmax of 38.71 GHz were measured on the device.Load-pull measurements were performed and analyzed under (-3.5,28) V,(-3.5,34) V and (-3.5,40) V gate/drain direct current bias in class-AB,respectively.The uncooled device showed high linear power gain of 17.04 dB and high power-added efficiency of 50.56％ at 8 GHz when drain biased at (-3.5,28) V.In addition,when drain biased at (-3.5,40) V,the device exhibited a saturation output power dens-ity up to 6.21 W/mm at 8 GHz,with a power gain of 11.94 dB and a power-added efficiency of 39.56％.Furthermore,the low fmax/fT ratio and the variation of the power sweep of the device at 8 GHz with drain bias voltage were analyzed.     

一种考虑端口引线趋肤效应的GaAs PHEMT器件小信号模型

为了精确地表征高频GaAs赝配高电子迁移率晶体管(PHEMT)的器件特性,提出了一种考虑端口引线趋肤效应的GaAs PHEMT器件小信号模型。采用传输线理论,建立GaAs PHEMT的源-漏电压为0 V情况下沟道的T型等效网络。以量化沟道电阻为中间项,推导出含有趋肤效应模型的拓扑结构并提出参数解析提取方法。结合趋肤效应的高频响应特征,从频率高于40 GHz的测试S参数中剥离10 GHz以下的非本征参数,然后从剥离之后的网络参数中提取趋肤效应模型参数值。采用总栅宽为4×25μm GaAs PHEMT管芯用于模型和模型参数提取方法的验证。结果显示在2~110 GHz下,该模型的仿真结果与测试结果吻合较好。     

T形栅In0.52Al0.48As/In0.6Ga0.4As MHEMTs功率器件

利用电子束光刻技术制备了200nm栅长GaAs基T型栅InAlAs/lnGaAs MHEMT器件.该GaAs基MHEMT器件具有优越的直流、高频和功率性能,跨导、饱和漏电流密度、阈值电压、电流增益截止频率和最大振荡频率分别达到510mS/mm,605mA/mm,-1.8V,138GHz和78GHz.在8GHz下,输人功率为-0.88(2.11)dBm时,输出功率、增益、PAE、输出功率密度分别为14.05(13.79)dBm,14.9(11.68)dB,67.74(75.1)%,254(239)mW/mm,为进一步研究高性能GaAs基MHEMT功率器件奠定了基础.