磁控溅射AIN介质MIS栅结构的AlGaN/GaN HEMT

报道了一种X波段输出功率密度达10.4 W/mm的SiC衬底AIGaN/GaN MIS-HEMT,器件研制中采用了MIS结构、凹槽栅以及场板,其中MIS结构中采用了磁控溅射的A1N介质作为绝缘层.采用MIS结构后,器件击穿电压由80 V提高到了180 V以上,保证了器件能够实现更高的工作电压.在8 GHz、55 V的工作电压下,研制的1 mm栅宽AlGaN/GaN MIS-HEMT输出功率达到了10.4 W,此时器件的功率增益和功率附加效率分别达到了6.56 dB和39.2%.     

磁控溅射AlN介质的14W/mm AlGaN/GaN MIS-HEMT

介绍了一种采用磁控溅射AlN介质作为绝缘层的的SiC衬底AlGaN/GaN MIS-HEMT.器件研制中采用了凹槽栅和场板结构.采用MIS结构后,器件击穿电压由80 V提高到了180 V以上,保证了器件能够实现更高的工作电压.在2 GHz、75 V工作电压下,研制的200μm栅宽AlGaN/GaNMIS-HEMT输出功率密度达到了14.4 W/mm,器件功率增益和功率附加效率分别为20.51 dB和54.2%.     

磁控溅射AIN介质的14W／mm AlGaN／GaN MIS-HEMT

介绍了一种采用磁控溅射AlN介质作为绝缘层的的SiC衬底AlGaN／GaN MIS-HEMT。器件研制中采用了凹槽栅和场板结构。采用MIS结构后,器件击穿电压由80V提高到了180V以上,保证了器件能够实现更高的工作电压。在2GHz、75V工作电压下,研制的200μm栅宽AlGaN／GaNMIS-HEMT输出功率密度达到了14．4W／mm,器件功率增益和功率附加效率分别为20．51dB和54．2％。     

14W X波段AlGaN/GaN HEMT功率MMIC

报道了研制的SiC衬底AIGaN/GaN HEMT微带结构微波功率MMIC,芯片工艺采用凹槽栅场板结构提高AlGaN/GaNHEMTs的微波功率特性.S参数测试结果表明AlGaN/GaN HEMTs的频率特性随器件的工作电压变化显著.研制的该2级功率MMIC在9～11GHz带内30V工作,输出功率大于10W,功率增益大于12dB,带内峰值输出功率达到14.7W,功率增益为13.7dB,功率附加效率为23%,该芯片尺寸仅为2.0mm×1.1mm.与已发表的X波段AlGaN/GaN HEMT功率MMIC研制结果相比,本项工作在单位毫米栅宽输出功率和芯片单位面积输出功率方面具有优势.     

非掺杂AlGaN/GaN微波功率HEMT

报道了研制的AlGaN/GaN微波功率HEMT,该器件采用以蓝宝石为衬底的非掺杂AlGaN/GaN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SiN介质进行器件的钝化.研制的200μm栅宽T型布局AlGaN/GaN HEMT在1.8GHz,Vds=30V时输出功率为28.93dBm,输出功率密度达到3.9W/mm,功率增益为15.59dB,功率附加效率(PAE)为48.3%.在6.2GHz,Vds=25V时该器件输出功率为27.06dBm,输出功率密度为2.5W/mm,功率增益为10.24dB,PAE为35.2%.     

凹槽栅场调制板结构AlGaN/GaN HEMT

研制的SiC衬底上的AlGaN/GaN微波功率HEMTs,采用凹槽栅和场调制板结构有效抑制了器件的电流崩塌,提高了器件的击穿电压和器件的微波功率特性.研制的1mm栅宽器件在8GHz,34V工作电压下,饱和输出功率达到了9.05W,功率增益为7.5dB,功率附加效率为46%.     

0.15μm GaN HEMT及其应用

报道了毫米波应用的0.15μm场板结构GaN HEMT。器件研制采用了76.2mm(3英寸)SiC衬底上外延生长的AlGaN/GaN异质结构材料,该材料由MOCVD技术生长并引入了掺Fe GaN缓冲层技术以提升器件击穿电压。器件栅脚和集成了场板的栅帽均由电子束光刻实现,并采用栅挖槽技术来控制器件夹断电压。研制的2×75μm栅宽GaN HEMT在24V工作电压、35GHz频率下的负载牵引测试结果显示其输出功率密度达到了4W/mm,对应的功率增益和功率附加效率分别为5dB和35%。采用该0.15μm GaN HEMT技术进行了Ka波段GaN功率MMIC的研制,所研制的功率MMIC在24V工作电压下脉冲工作时(100μs脉宽、10%占空比),29GHz频点处饱和功率达到了10.64W。     

14W X波段AlGaN/GaN HEMT功率MMIC

报道了研制的SiC衬底AIGaN/GaN HEMT微带结构微波功率MMIC,芯片工艺采用凹槽栅场板结构提高AlGaN/GaNHEMTs的微波功率特性.S参数测试结果表明AlGaN/GaN HEMTs的频率特性随器件的工作电压变化显著.研制的该2级功率MMIC在9～11GHz带内30V工作,输出功率大于10W,功率增益大于12dB,带内峰值输出功率达到14.7W,功率增益为13.7dB,功率附加效率为23%,该芯片尺寸仅为2.0mm×1.1mm.与已发表的X波段AlGaN/GaN HEMT功率MMIC研制结果相比,本项工作在单位毫米栅宽输出功率和芯片单位面积输出功率方面具有优势.     

凹槽栅场调制板结构AlGaN/GaN HEMT

研制的SiC衬底上的AlGaN/GaN微波功率HEMTs,采用凹槽栅和场调制板结构有效抑制了器件的电流崩塌,提高了器件的击穿电压和器件的微波功率特性.研制的1mm栅宽器件在8GHz,34V工作电压下,饱和输出功率达到了9.05W,功率增益为7.5dB,功率附加效率为46%.     

高性能1mm SiC基AlGaN/GaN功率HEMT研制

在6H-SiC衬底上,外延生长了AlGaN/GaN HEMT结构,设计并实现了高性能1mm AlGaN/GaN微波功率HEMT,外延材料利用金属有机物化学气相淀积技术生长.测试表明,该lmm栅宽器件栅长为0.8μm,输出电流密度达到1.16A/mm,跨导为241mS/mm,击穿电压＞80V,特征频率达到20GHz,最大振荡频率为28GHz.5.4GHz连续波测试下功率增益为14.2dB,输出功率达4.1W,脉冲条件测试下功率增益为14.4dB,输出功率为5.2W,两端口阻抗特性显示了在微波应用中的良好潜力.     

X波段大功率GaN HEMT的研制

在研制了AlGaN/GaN HEMT外延材料的基础上,采用标准工艺制作了2.5mm大栅宽AlGaN/GaNHEMT。直流测试中,Vg=0V时器件的最大饱和电流Ids可达2.4A,最大本征跨导Gmax为520mS,夹断电压Voff为-5V;通过采用带有绝缘层的材料结构及离子注入的隔离方式,减小了器件漏电,提高了击穿电压,栅源反向电压到-20V时,栅源漏电在10-6A数量级;单胞器件测试中,Vds=34V时,器件在8GHz下连续波输出功率为16W,功率增益为6.08dB,峰值功率附加效率为43.0%;2.5mm×4四胞器件,在8GHz下,连续波输出功率42W,功率增益8dB,峰值功率附加效率34%。     

标准氟离子注入实现增强型GaN基功率器件

介绍了一种直接利用离子注入机对AlGaN/GaN高电子迁移率晶体管(HEMT)器件的栅下进行氟(F)离子注入的方法,成功实现了增强型HEMT器件,阈值电压从耗尽型器件的-2.6V移动到增强型器件的+1.9V.研究了注入剂量对器件性能的影响,研究发现随着注入剂量的不断增加,阈值电压不断地正向移动,但由于存在高能F离子的注入损伤,器件的正向栅极漏电随着注入剂量的增加而不断上升,阈值电压正向移动也趋于饱和.因此,提出采用在AlGaN/GaN异质结表面沉积栅介质充当能量吸收层,降低离子注入过程中的损伤,成功实现了阈值电压为+3.3 V,饱和电流密度约为200 mA/mm,同时具有一个较高的开关比109的增强型金属-绝缘层-半导体HEMT (MIS-HEMT)器件.     

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.     

SiN钝化前的NF3等离子体处理对AlGaN/GaN HEMT性能的影响

研究了SiN钝化前利用感应耦合等离子体（ICP）对AlGaN/GaN HEMT表面进行NF3等离子体处理对器件性能的影响. 结果表明,运用低能量的NF3等离子体处理钝化前的AlGaN/GaN HEMT表面能有效抑制器件电流崩塌,而器件直流及微波小信号特性则未受影响. 微波功率测试表明,经过6min NF3等离子体处理的AlGaN/GaN HEMT在2GHz, 30V工作电压下达到6.15W/mm的输出功率密度,而未经过处理的器件只达到1.82W/mm的输出功率密度.     

GaN-based optoelectronic devices on sapphire and Si substrates

A recessed gate AlGaN/GaN high-electron mobility transistor (HEMT) on sapphire (0 0 0 1), a GaN metal-semiconductor field-effect transistor (MESFET) and an InGaN multiple-quantum well green light-emitting diode (LED) on Si (1 1 1) substrates have been grown by metalorganic chemical vapor deposition. The AlGaN/GaN intermediate layers have been used for the growth of GaN MESFET and LED on Si substrates. A two-dimensional electron gas mobility as high as 9260 cm²/V s with a sheet carrier density of 4.8×10¹² cm⁻² was measured at 4.6 K for the AlGaN/GaN heterostructure on the sapphire substrate. The recessed gate device on sapphire showed a maximum extrinsic transconductance of 146 mS/mm and a drain–source current of 900 mA/mm for the AlGaN/GaN HEMT with a gate length of 2.1 μm at 25°C. The GaN MESFET on Si showed a maximum extrinsic transconductance of 25 mS/mm and a drain–source current of 169 mA/mm with a complete pinch-off for the 2.5-μm-gate length. The LED on Si exhibited an operating voltage of 18 V, a series resistance of 300 Ω, an optical output power of 10 μW and a peak emission wavelength of 505 nm with a full-width at half-maximum of 33 nm at 20 mA drive current.     

蓝宝石衬底上槽栅型X波段增强型AlGaN/GaN HEMT

研制了一款X波段增强型AlGaN/GaN高电子迁移率晶体管(HEMT)。在3英寸(1英寸=2.54 cm)蓝宝石衬底上采用低损伤栅凹槽刻蚀技术制备了栅长为0.3μm的增强型AlGaN/GaN HEMT。所制备的增强型器件的阈值电压为0.42 V,最大跨导为401 mS/mm,导通电阻为2.7Ω·mm。器件的电流增益截止频率和最高振荡频率分别为36.1和65.2 GHz。在10 GHz下进行微波测试,增强型AlGaN/GaN HEMT的最大输出功率密度达到5.76 W/mm,最大功率附加效率为49.1%。在同一材料上制备的耗尽型器件最大输出功率密度和最大功率附加效率分别为6.16 W/mm和50.2%。增强型器件的射频特性可与在同一晶圆上制备的耗尽型器件相比拟。     

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.     

RF and microwave characteristics of a 10 nm thick InGaN-channel gate recessed HEMT

A new depletion-mode gate recessed AlGaN/InGaN/GaN-high electron mobility transistor(HEMT)with 10 nm thickness of InGaN-channel is proposed.A growth of AlGaN over GaN leads to the formation of twodimensional electron gas(2DEG)at the heterointerface.High 2DEG density(ns)is achieved at the heterointerface due to a strain induced piezoelectric effect between AlGaN and GaN layers.The electrons are confined in the InGaN-channel without spilling over into the buffer layer,which also reduces the buffer leakage current.From the input transfer characteristics the threshold voltage is obtained as 4:5 V and the device conducts a current of 2 A/mm at a drain voltage of 10 V.The device also shows a maximum output current density of 1.8 A/mm at Vds of 3 V.The microwave characteristics like transconductance,cut-off frequency,max frequency of oscillation and Mason’s Unilateral Gain of the device are studied by AC small-signal analysis using a two-port network.The stability and power performance of the device are analyzed by the Smith chart and polar plots respectively.To our knowledge this proposed InGaN-channel HEMT structure is the first of its kind.     

A Ku-band 3.4 W/mm power AlGaN/GaN HEMT on a sapphire substrate

This Daper describes the first domestic Ku-band power AlGaN/GaN HEMT fabricated on a sapphire substrate.The device with a gate width of 0.5 mm and a gate length of 0.35 μm has exhibited an extrinsic current gain cutoff frequency of 20 GHz and an extrinsic maximum frequency of oscillation of 75 GHz.Under V_(DS)=30 V, CW operating conditions at 14 GHz,the device exhibits a linear gain of 10.4 dB and a 3-dB-gain-compressed output power of 1.4 W with a Dower added efficiency of 41%.Under pulse operating conditions,the linear gain is 12.8 dB and the 3-dB-compressed output power is 1.7 W The power density reaches 3.4 W/mm.