跨导为220mS／mm的AIGaN／GaN HEMT

介绍了AIGaN／GaN HEMT器件的研制及室温下器件特性的测试。漏源欧姆接触采用Ti／Al／Pt／Au．肖特基结金属为Pt／Au。器件栅长为1μm，获得最大跨导220mS／mm，最大的漏源饱和电流密度0．72A／ram。由S参数测量推出器件的截止频率和最高振荡频率分别为12GHz和24GHz。     

AlGaN/GaN HEMT器件的研制

介绍了AlGaN/GaNHEMT器件的研制及室温下器件特性的测试.漏源欧姆接触采用Ti/Al/Pt/Au ,肖特基结金属为Pt/Au .器件栅长为1μm ,获得的最大跨导为12 0mS/mm ,最大的漏源饱和电流密度为0 95A/mm .     

AlGaN/GaN HEMT器件的研制

介绍了AlGaN/GaN HEMT器件的研制及室温下器件特性的测试.漏源欧姆接触采用Ti/Al/Pt/Au,肖特基结金属为Pt/Au.器件栅长为1μm,获得的最大跨导为120mS/mm,最大的漏源饱和电流密度为0.95A/mm.     

基于蓝宝石衬底的高性能AlGaN/GaN二维电子气材料与HEMT器件

利用低压MOCVD技术在蓝宝石衬底上生长了高性能的Al Ga N/Ga N二维电子气(2 DEG)材料,室温和77K温度下的电子迁移率分别为94 6和2 5 78cm2 /(V·s) ,室温和77K温度下2 DEG面密度分别为1.3×10 1 3和1.2 7×10 1 3cm- 2 .并利用Al Ga N/Ga N二维电子气材料制造出了高性能的HEMT器件,栅长为1μm,源漏间距为4 μm,最大电流密度为4 85 m A/mm(VG=1V) ,最大非本征跨导为170 m S/mm(VG=0 V) ,截止频率和最高振荡频率分别为6 .7和2 4 GHz     

非掺杂AlGaN/GaN微波功率HEMT

报道了研制的Al Ga N / Ga N微波功率HEMT,该器件采用以蓝宝石为衬底的非掺杂Al Ga N/ Ga N异质结构,器件工艺采用了Ti/ Al/ Ni/ Au欧姆接触和Ni/ Au肖特基势垒接触以及Si N介质进行器件的钝化.研制的2 0 0μm栅宽T型布局Al Ga N / Ga N HEMT在1.8GHz,Vds=30 V时输出功率为2 8.93d Bm,输出功率密度达到3.9W/mm ,功率增益为15 .5 9d B,功率附加效率(PAE)为4 8.3% .在6 .2 GHz,Vds=2 5 V时该器件输出功率为2 7.0 6 d Bm ,输出功率密度为2 .5 W/ mm ,功率增益为10 .2 4 d B,PAE为35 .2 % .     

MBE生长的跨导为186mS/mm的AlGaN/GaN HEMT

用分子束外延 ( MBE)技术研制出了 Al Ga N/Ga N高电子迁移率晶体管 ( HEMT)材料 ,其室温迁移率为 10 35cm2 /V· s、二维电子气浓度为 1.0× 10 13 cm - 2 ;77K迁移率为 2 6 53cm2 /V· s、二维电子气浓度为 9.6× 10 12 cm- 2 。用此材料研制了栅长为 1μm、栅宽为 80μm、源 -漏间距为 4μm的 Al Ga N/Ga N HEMT,其室温最大非本征跨导为 186 m S/mm、最大漏极饱和电流密度为 92 5m A/mm、特征频率为 18.8GH z。另外 ,还研制了具有 2 0个栅指 (总栅宽为 2 0× 80μm =1.6 mm )的大尺寸器件 ,该器件的最大漏极饱和电流为 1.33A。     

蓝宝石衬底AlGaNöGaN 功率HEM Ts 研制

基于蓝宝石衬底的高微波特性 Al Ga N/Ga N HEMTs功率器件 ,器件采用了新的欧姆接触和新型空气桥方案。测试表明 ,器件电流密度 0 .784A/mm,跨导 1 97m S/mm,关态击穿电压 >80 V,截止态漏电很小 ,栅宽 1 mm的器件的单位截止频率 ( f T)达到 2 0 GHz,最大振荡频率 ( fmax) 2 8GHz,2 GHz脉冲测试下 ,栅宽 0 .75 mm器件 ,功率增益1 1 .8d B,输出功率 3 1 .2 d Bm,功率密度 1 .75 W/mm。     

不同AlGaN层厚度的AlGaN/GaN高电子迁移率晶体管的静态特性

利用金属有机化合物气相外延技术研究了Al Ga N/ Ga N高电子迁移率晶体管(HEMT)结构的外延生长及器件制作,重点比较了具有不同Al Ga N层厚度的HEMT器件的静态特性.实验发现具有较薄Al Ga N隔离层的结构表现出较好的器件特性.栅长为1μm的器件获得了6 5 0 m A/ m m的最大饱和电流密度和10 0 m S/ mm的最大跨导.     

GaAs基InAlAs/InGaAsMHEMT直流特性研究

报道了用 MBE技术生长的 Ga As基 In Al As/In Ga As改变结构高电子迁移率晶体管 (MHEMT)的制作过程和器件的直流性能。对于栅长为 0 .8μm的器件 ,最大非本征跨导和饱和电流密度分别为 3 5 0 m S/mm和1 90 m A/mm。源漏击穿电压和栅反向击穿电压分别为 4V和 7.5 V。这些直流特性超过了相同的材料和工艺条件下 Ga As基 PHEMT的水平 ,与 In P基 In Al As/In Ga As HEMT的性能相当     

分子束外延AlGaN/GaN异质结场效应晶体管材料

用自组装的氨源分子束外延 (NH3-MBE)系统和射频等离子体辅助分子束外延 (PA-MBE)系统在 C面蓝宝石衬底上外延了优质 Ga N以及 Al Ga N/Ga N二维电子气材料。Ga N膜 (1 .2 μm厚 )室温电子迁移率达3 0 0 cm2 /V· s,背景电子浓度低至 2× 1 0 1 7cm- 3。双晶 X射线衍射 (0 0 0 2 )摇摆曲线半高宽为 6arcmin。 Al Ga N/Ga N二维电子气材料最高的室温和 77K二维电子气电子迁移率分别为 73 0 cm2 /V·s和 1 2 0 0 cm2 /V· s,相应的电子面密度分别是 7.6× 1 0 1 2 cm- 2和 7.1× 1 0 1 2 cm- 2 ;用所外延的 Al Ga N/Ga N二维电子气材料制备出了性能良好的 Al Ga N/Ga N HFET(异质结场效应晶体管 ) ,室温跨导为 5 0 m S/mm(栅长 1 μm) ,截止频率达 1 3 GHz(栅长 0 .5μm)。该器件在 3 0 0°C出现明显的并联电导 ,这可能是材料中的深中心在高温被激活所致     

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.     

Performance dependence of InGaP/InGaAs/GaAs pHEMTs on gatemetallization

The performance of InGaP-based pHEMTs as a function of gate metallization is examined for Mo/Au, Ti/Au, and Pt/Au gates. DC and microwave performance of pHEMT's with 0.7-μm gate lengths is evaluated. Transconductance, threshold voltage, f_t, and f_max are found to depend strongly on gate metallization. High-speed performance is achieved, with f_t of 41.3 GHz and f _max of 101 GHz using Mo/Au gates. The difference in performance between devices with different gate metallizations is postulated to be due to a combination of the difference in Schottky barrier heights and different gate-to-channel spacings due to penetration of the gate metal into the InGaP barrier layer     

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。     

200nm栅长In0.52Al0.48As/In0.6Ga0.4As MHEMTs器件

利用电子束光刻技术制备出200nm栅长GaAs基InAlAs/InGaAs MHEMT器件.Ti/Pt/Au蒸发作为栅极金属.同时为了减少栅寄生电容和寄生电阻,采用3层胶工艺,实现了T型栅.GaAs基MHEMT 器件获得了优越的直流和高频性能,跨导、饱和漏电流密度、域值电压、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,110GHz及72GHz,为进一步研究高性能GaAs基MHEMT器件奠定了基础.     

0.15-$muhboxm$-Gate InAlAs/InGaAs/InP E-HEMTs Utilizing Ir/Ti/Pt/Au Gate Structure

High-current 0.15-mum-gate enhancement-mode high-electron mobility transistors utilizing Ir/Ti/Pt/Au gate metallization were fabricated using a new process including a high-temperature gate anneal that is required for Schottky-barrier height enhancement for the Ir-based gate contact. SiN_x encapsulation was employed to prevent thermal degradation of device layer during the high-temperature gate anneal. Excellent enhancement-mode operation, with a threshold voltage of 0.1 V and I_DSS of 2.1 mA/mm, was realized. Both the annealed and unannealed devices exhibited high g_m,max and I_D,max of 800 mS/mm and 430 mA/mm, respectively. A unity current-gain cutoff frequency f_T of 151 GHz and a maximum oscillation frequency f_MAX of 172 GHz were achieved. From the dc and RF characteristics, it can be deduced that there was no degradation of the gate contact and the heterostructure due to gate annealing. Furthermore, it was found that the gate diffusion during gate annealing was negligible since no increase in g_m,max was observed     

Enhancement-mode high electron mobility transistors (E-HEMTs)lattice-matched to InP

The fabrication and characterization of high-speed enhancement-mode InAlAs/InGaAs/InP high electron mobility transistors (E-HEMTs) have been performed. The E-HEMT devices were made using a buried-Pt gate technology. Following a Pt/Ti/Pt/Au gate metal deposition, the devices were annealed in a nitrogen ambient, causing the bottom Pt layer to sink toward the channel. This penetration results in a positive shift in threshold voltage. The dc and RF performance of the devices has been investigated before and after the gate annealing process. In addition, the effect of the Pt penetration was investigated by fabricating two sets of devices, one with 25 nm of Pt as the bottom layer and the other with a 5.0 nm bottom Pt layer. E-HEMTs were fabricated with gate lengths ranging from 0.3 to 1.0 μm. A maximum extrinsic transconductance (g_mext) of 701 mS/mm and a threshold voltage (V_T) of 167 mV was measured for 0.3 μm gate length E-HEMTs. In addition, these same devices demonstrated excellent subthreshold characteristics as well as large off-state breakdown voltages of 12.5 V. A unity current-gain cutoff frequency (f _t) of 116 GHz was measured as well as a maximum frequency of oscillation (f_max) of 229 GHz for 0.3 μm gate-length E-HEMTs     

200nm栅长In0.52Al0.48As／In0.6Ga0.4As MHEMTs器件

利用电子束光刻技术制备出200nm栅长GaAs基InAIAs/InGaAs MHEMT器件.Ti/Pt/Au蒸发作为栅极金属.同时为了减少栅寄生电容和寄生电阻,采用3层胶工艺,实现了T 型栅. GaAs基MHEMT 器件获得了优越的直流和高频性能,跨导、饱和漏电流密度、域值电压、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, 110GHz及 72GHz,为进一步研究高性能GaAs基MHEMT器件奠定了基础.     

Super low-noise HEMTs with a T-shaped WSix gate

A T-shaped quarter-micron gate structure composed of WSi_x /Ti/Pt/Au has been developed for low-noise AlGaAs/GaAs HEMTs. The gate resistance R_g was reduced to 0.3 Ω for devices with 200 μm-wide gates despite using WSi_x, and the source resistance R_s reached 0.28 Ω mm by minimising the source-gate distance using a self-alignment technique. This HEMT exhibited the lowest reported noise figure of 0.54 dB with an associated gain of 12.1 dB at 12 GHz     

7.1 GHz bandwidth monolithically integratedIn0.53Ga0.47As/In0.52Al0.48As PIN-HBT transimpedance photoreceiver

A monolithically integrated photoreceiver using an InAlAs/InGaAs HBT-based transimpedance amplifier has been fabricated and characterized. The p-i-n photodiode is implemented using the base-collector junction of the HBT. The 5 μm×5 μm emitter area transistors have self-aligned base metal and non-alloyed Ti/Pt/Au contacts. Discrete transistors demonstrated f_T and f_max of 54 GHz and 51 GHz, respectively. The amplifier demonstrated a -3 dB transimpedance bandwidth of 10 GHz and a gain of 40 dBΩ. The integrated photoreceiver with a 10 μm×10 μm p-i-n photodiode showed a -3 dB bandwidth of 7.1 GHz