槽栅MOSHEMT研制与特性分析

An A1GaN/GaN recessed-gate MOSHEMT was fabricated on a sapphire substrate. The device, which has a gate length of 1μm and a source-drain distance of 4μm, exhibits a maximum drain current density of 684mA/mrn at Vgs = 4V with an extrinsic transconductance of 219 mS/mm. This is 24.3% higher than the transconductance of conventional A1GaN/GaN HEMTs. The cut-off frequency and the maximum frequency of oscillation are 9.2 GHz and 14.1 GHz, respectively. Furthermore, the gate leakage current is two orders of magnitude lower than for the conventional Schottky contact device.     

增强型AlGaN/GaN槽栅HEMT

成功研制出蓝宝石衬底的槽栅增强型AlGaN/GaN HEMT. 栅长1.2μm,源漏间距4μm,槽深15nm的器件在3V栅压下饱和电流达到332mA/mm,最大跨导为221mS/mm,阈值电压为0.57V, ft和fmax分别为5.2和9.3GHz. 比较刻蚀前后的肖特基I-V特性,证实了槽栅刻蚀过程中非有意淀积介质层的存在. 深入研究了增强型器件亚阈特性和频率特性.     

增强型AlGaN/GaN槽栅HEMT

成功研制出蓝宝石衬底的槽栅增强型AlGaN/GaN HEMT.栅长1.2μm.源漏间距4μm,槽深15nm的器件在3V栅压下饱和电流达到332mA/mm,最大跨导为221mS/mm,阈值电压为0.57V,ft和,fmax分别为5.2和9.3GHz.比较刎蚀前后的肖特基,Ⅰ-Ⅴ特性,证实了槽栅刻蚀过程中非有意淀积介质层的存在.深入研究了增强型器件亚阈特性和频率特性.     

高跨导AlGaN/GaN HEMT器件

报道了生长在蓝宝石衬底上的AlGaN/GaN HEMT器件的制造工艺以及在室温下器件的性能.器件的栅长为1.0μm,源漏间距为4.0μm.器件的最大电流密度达到1000mA/mm,最大跨导高达198mS/mm,转移特性曲线表现出增益带宽较宽的特点.同时由所测得的S参数推出栅长为1.0μm器件的截止频率(fT)和最高振荡频率(fmax)分别为18.7GHz和19.1GHz.     

高跨导AlGaN/GaN HEMT器件

报道了生长在蓝宝石衬底上的AlGaN/GaNHEMT器件的制造工艺以及在室温下器件的性能.器件的栅长为1 0 μm ,源漏间距为4 0 μm .器件的最大电流密度达到1 0 0 0mA/mm ,最大跨导高达1 98mS/mm ,转移特性曲线表现出增益带宽较宽的特点.同时由所测得的S参数推出栅长为1 0 μm器件的截止频率(fT)和最高振荡频率(fmax)分别为1 8 7GHz和1 9 1GHz.     

AlGaN/GaN double-channel HEMT

The fabrication of AlGaN/GaN double-channel high electron mobility transistors on sapphire substrates is reported. Two carrier channels are formed in an AlGaN/GaN/AlGaN/GaN multilayer structure. The DC performance of the resulting double-channel HEMT shows a wider high transconductance region compared with single-channel HEMT. Simulations provide an explanation for the influence of the double-channel on the high transconductance region. The buffer trap is suggested to be related to the wide region of high transconductance. The RF characteristics are also studied.     

AlGaN/GaN double-channel HEMT

正The fabrication of AlGaN/GaN double-channel high electron mobility transistors on sapphire substrates is reported.Two carrier channels are formed in an AlGaN/GaN/AlGaN/GaN multilayer structure.The DC performance of the resulting double-channel HEMT shows a wider high transconductance region compared with single-channel HEMT. Simulations provide an explanation for the influence of the double-channel on the high transconductance region.The buffer trap is suggested to be related to the wide region of high transconductance.The RF characteristics are also studied.     

AlGaN/GaN HEMTs with 0.2μm V-gate recesses for X-band application

正AlGaN/GaN HEMTs with 0.2μm V-gate recesses were developed.The 0.2μm recess lengths were shrunk from the 0.6μm designed gate footprint length after isotropic SiN deposition and anisotropic recessed gate dry etching.The AlGaN/GaN HEMTs with 0.2μm V-gate recesses on sapphire substrates exhibited a current gain cutoff frequency f_t of 35 GHz and a maximum frequency of oscillation f_(max) of 60 GHz.At 10 GHz frequency and 20 V drain bias,the V-gate recess devices exhibited an output power density of 4.44 W/mm with the associated power added efficiency as high as 49%.     

应用于X波段的0.2um V型栅槽AlGaN/GaN HEMT

研制出0.2um栅长 V型栅槽AlGaN/GaN HEMT。该0.2um栅槽是由0.6um 的光刻设计尺寸经过SiN各项同性淀积和各项异性刻蚀而形成。该0.2um栅长V型栅槽AlGaN/GaN HEMT最大截止频率为35GHz,最大震荡频率60GHz。在10GHz频率和20V漏偏压下,该器件最大输出功率达到4.44 W/mm ,功率附加效率49%。     

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 % .     

F等离子体处理 AlGaN/GaN HEMT击穿电压和电流崩塌研究

F等离子体处理工艺被广泛的应用于 AlGaN/GaN HEMT增强型器件的研制和栅前处理工艺。本文研究了低功率F处理 AlGaN/GaN HEMT的击穿特性和电流崩塌特性。随着F处理时间的增加,饱和电流下降,阈值电压正向移动。对不同F处理时间的器件肖特基特性分析后发现,120s的F处理后器件栅泄漏电流明显减小,器件击穿电压提高,当F处理时间大于120s后,由于长时间F处理带来的损伤器件栅泄漏电流没有继续减小。采用不同偏置下的双脉冲测试对不同F处理时间的电流崩塌特性进行了研究,低功率F处理后没有发现明显的电流崩塌现象。     

4H-SiC衬底AlGaN/GaN高电子迁移率晶体管的研制

报道了在4H-SiC衬底上AlGaN/GaN高电子迁移率晶体管(HEMT)的研制和室温特性测试结果.器件采用栅长为0.7μm,夹断电压为-3.2V,获得了最高跨导为202mS/mm,最大漏源饱和电流密度为915mA/mm的优良性能和结果.     

微波功率AlGaN/GaN HEMT的研究进展

文章论述了AlGaN/GaN高电子迁移率晶体管(HEMT)在微波功率领域应用的优势,详细介绍了微波功率AlGaN/GaN HEMT的工艺进展以及器件的直流和频率特性,评述了其最新进展及今后发展方向.     

F注入AlGaN/GaN增强型HEMT

The fabrication of enhancement-mode AlGaN/GaN HEMTs by fluorine plasma treatment on sapphire substrates is reported. A new method is used to fabricate devices with different fluorine plasma RF power treatments on one wafer to avoid differences between different wafers. The plasma-treated gate regions of devices treated with different fluorine plasma RF powers were separately opened by a step-and-repeat system. The properties of these devices are compared and analyzed. The devices with 150 W fluorine plasma treatment power and with 0.6 μm gate-length exhibited a threshold voltage of 0.57 V, a maximum drain current of 501 mA/mm, a maximum transconductance of 210 mS/mm, a current gain cutoff frequency of 19.4 GHz and a maximum oscillation frequency of 26 GHz. An excessive fluorine plasma treatment power of 250 W results in a small maximum drain current, which can be attributed to the implantation of fluorine plasma in the channel.     

多栅指AlGaN/GaN HEMT器件自热效应研究

Self-heating in multi-finger AlGaN/GaN high-electron-mobility transistors(HEMTs) is investigated by measurements and modeling of device junction temperature under steady-state operation.Measurements are carried out using micro-Raman scattering to obtain the detailed and accurate temperature distribution of the device.The device peak temperature corresponds to the high field region at the drain side of gate edge.The channel temperature of the device is modeled using a combined electro-thermal model considering 2DEG transport characteristics and the Joule heating power distribution.The results reveal excellent correlation to the micro-Raman measurements, validating our model for the design of better cooled structures.Furthermore,the influence of layout design on the channel temperature of multi-finger AlGaN/GaN HEMTs is studied using the proposed electro-thermal model, allowing for device optimization.     

蓝宝石衬底上AlGaN/GaN HEMT自热效应研究

建立了包含“自热效应”的A lG aN/G aN HEM T(高电子迁移率晶体管)直流I-V特性解析模型。从理论的角度分析了自热效应对A lG aN/G aN HEM T器件的影响,并同已有的实验结果进行了对比,符合较好。证明基于这种模型的理论分析适于A lG aN/G aN HEM T器件测试及应用的实际情况。     

蓝宝石衬底上AIGaN／GaN HEMT自热效应研究

建立了包含“自热效应”的AIGaN／GaN HEMT（高电子迁移率晶体管）直流I-V特性解析模型。从理论的角度分析了自热效应对AlGaN／GaN HEMT器件的影响，并同已有的实验结果进行了对比，符合较好。证明基于这种模型的理论分析适于AIGaN／GaN HEMT器件测试及应用的实际情况。     

调制掺杂对AlGaN/GaN HEMT材料电学性能的影响

利用范德堡Hall方法和汞探针C-V方法,研究了不同Si调制掺杂浓度对AlGaN/GaN HEMT材料电学性质的影响.发现si掺杂可以改善材料电学性能,二维电子气(2DEG)面密度和方块电阻(ns×μ)可以通过si调制掺杂精确控制.当Si掺杂浓度为3×10(18)cm-3时,得到了最低的方块电阻360Ω/□.尽管受到高浓度电子和离化杂质对二维电子气的散射影响,迁移率仍可达1220cm2/(V·s).分析了范德堡Hall方法和汞探针C-V方法的差别,同时测得材料的阈值电压也在合理范围.     

HEMT太赫兹探测器响应度和NEP的检测与分析

在0.8～1.1 THz内,对AlGaN/GaN高电子迁移率晶体管(HEMT)太赫兹探测器的响应度和噪声等效功率进行了具体测试和分析。在太赫兹波辐射下,HEMT太赫兹探测器源漏端产生能被栅压灵敏调控的直流光电流。该型探测器在300 K和77 K下的电流响应度分别为83 mA/W和4.1 A/W,电压响应度分别为4 kV/W和50 kV/W,噪声等效功率分别达到22 pW/Hz0.5和1 pW/Hz0.5。采用两种较为典型的测量方法,通过对实验结果的比较,确定了影响该类型探测器的响应度和噪声等效功率的主要因素,并提出了增强响应度和降低噪声等效功率的具体措施。     

Load-pull measurement analysis of AlGaN/GaN HEMT taking into account number of gate fingers

This paper investigates load-pull measurement of AlGaN/GaN high electron mobility transistors (HEMTs) at different numbers of gate fingers. Scalable small-signal models are extracted to analyze the relationship between each model''s parameters and the number of device''s gate fingers. The simulated S-parameters from the small-signal models are compared with the reflection coefficients measured from the load-pull measurement system at X-band frequencies of 8.8 and 10.4 GHz. The dependency between the number of device''s gate fingers and load-pull characterization is presented.