کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1795370 | 1524483 | 2007 | 5 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: AlGaN/GaN HEMTs on free-standing GaN substrates: MBE growth and microwave characterization AlGaN/GaN HEMTs on free-standing GaN substrates: MBE growth and microwave characterization](/preview/png/1795370.png)
We investigate the role of substrate temperature and gallium flux on the DC and microwave properties of AlGaN/GaN high electron mobility transistors grown by molecular-beam epitaxy on free standing, hydride vapor phase epitaxy grown GaN substrates. The free-standing substrates have threading dislocation densities below 107 cm−2. We find that AlGaN/GaN heterostructures with excellent properties may be grown within a wide range of substrate temperatures and fluxes. Electron Hall mobilities above 1700 cm2/V s and sheet resistances below 370 Ω/□ are typical. We are able to obtain high saturated drain currents with low gate leakage. Off-state breakdown voltages as high as 200 V with low drain and gate leakage currents have been measured. Further, we have measured microwave output power densities above 5 W/mm at 4 GHz with a power-added efficiency of 46% and an associated gain of 13.4 dB. We attribute improved electrical properties in these devices to the reduced threading dislocation density compared to those grown on non-native substrates.
Journal: Journal of Crystal Growth - Volumes 301–302, April 2007, Pages 429–433