Performance of the AlGaN HEMT structure with a gate extension
Performance of the AlGaN HEMT structure with a gate extension
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DOI：
10.1109/ted.2003.822036
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发表时间：
2004-01
影响因子：
3.1
通讯作者：
R. Thompson;T. Prunty;V. Kaper;J. Shealy
中科院分区：
文献类型：
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作者：
R. Thompson;T. Prunty;V. Kaper;J. Shealy
报道了AlGaN/GaN HEMTs在大漏偏压下的微波特性。器件结构采用有机金属气相外延技术在碳化硅衬底上生长，沟道方阻小于280欧姆/平方根。采用0.35/spl u/m长氮化硅窗口和0.18/spl u/m长金属悬垂构成的复合栅结构，提高了HEMT的击穿电压。这产生了金属-绝缘体-半导体(MIS)栅极向漏极延伸，绝缘体为氮化硅，厚度约40纳米。总栅宽为150/SPL mU/m的晶体管在60V漏偏压下的连续波(CW)输出功率密度和功率附加效率分别为16.5W/mm和47%。小信号测量得到的f/subT/和f/submax/分别为25.7 GHz和48.8 GHz。栅极+4 V时的最大漏电流为1.3 A/mm，弯曲电压为/SPL sim/5 V。此简要演示了采用优化的栅结构的AlGaN/GaN HEMT可以将器件操作扩展到更高的漏偏压，从而产生比以前观察到的更高的功率水平和效率。
The microwave performance of AlGaN/GaN HEMTs at large drain bias is reported. The device structures were grown by organometallic vapor phase epitaxy on SiC substrates with a channel sheet resistance less than 280 ohms/square. The breakdown voltage of the HEMT was improved by the composite gate structure consisting of a 0.35 /spl mu/m long silicon nitride window with a 0.18 /spl mu/m long metal overhang on either side. This produced an metal-insulator-semiconductor (MIS) gate extension toward the drain with the insulator, silicon nitride, approximately 40-nm-thick. Transistors with a 150 /spl mu/m total gate width have demonstrated a continuous wave (CW) 10 GHz output power density and power added efficiency of 16.5 W/mm and 47%, respectively when operated at 60 V drain bias. Small-signal measurements yielded an f/sub T/ and f/sub max/ of 25.7 GHz and 48.8 GHz respectively. Maximum drain current was 1.3 A/mm at +4 V on the gate, with a knee voltage of /spl sim/5 V. This brief demonstrates that AlGaN/GaN HEMTs with an optimized gate structure can extend the device operation to higher drain biases yielding higher power levels and efficiencies than have previously been observed.