X波段AlGaN/GaN HEMTs Γ栅场板结构研究(英文)  

Study on the X-Band Γ-Gate Field-Plate for AlGaN/GaN HEMTs

作　　者：王冬冬[1] 刘果果[1] 刘丹[1] 李诚瞻[1] 刘新宇[1] 

机构地区：[1]中国科学院微电子研究所,北京100029

出　　处：《半导体技术》2008年第10期850-854,922,共6页Semiconductor Technology

基　　金：Project Supported bythe State Key Development Programfor Basic Research of China(2002CB311903);The Key Innovation Programof Chinese Academy of Sciences(KGCX2-SW-107)

摘　　要：基于SiC衬底成功研制X波段0.25μm栅长带有Γ栅场板结构的AlGaN/GaN HEMT,对比T型栅结构器件,研究了Γ栅场板引入对器件直流、小信号及微波功率特性的影响。结果表明,Γ栅场板结构减小器件截止频率及振荡频率,但明显改善器件膝点电压和输出功率密度。针对场板长度分别为0.4、0.7、0.9、1.1μm,得出一定范围内增加场板长度,器件输出功率大幅度提高,并结合器件小信号模型提参结果分析原因。在频率8 GHz下,总栅宽1 mm,场板长度0.9μm的器件,连续波输出功率密度7.11 W/mm,功率附加效率(PAE)35.31%,相应线性增益10.25 dB。Conventional T-shaped gate and Г-gate field-plated structures were demonstrated and compared to each other from DC, RF and microwave power characterization. The results show that due to Г- gate field plate, degradation in the value of unity current gain frequency fT and maximum frequency of oscillation fmax are observed, but there is a significant improvement in knee-vohage and output power density. Also, 0.25 um gate-length AlGaN/GaN HEMTs with varying P-gate field-plate lengths of 0.4, 0.7, 0.9 and 1.1 um were fabricated on SiC substrates. With the increase of field-plate length within the optimum, output power density is improved dramatically, which is demonstrated by equivalent circuit analysis. At 8 GHz, a continuous-wave output power density is 7.11 W/mm with 35.31% power-added efficiency and 10.25 dB corresponding linear gain at Vds = 40 V for an 0.25 um × 1 mm device with field-plate length of 0.9 um .

关 键 词：ALGAN/GAN HEMTS Γ栅场板 截止频率 功率密度 

分 类 号：TN386[电子电信—物理电子学] TN401