Low 1/f Noise in AlGaN/GaN HFETs on SiC Substrates

✍ Scribed by Rumyantsev, S. ;Levinshtein, M. E. ;Gaska, R. ;Shur, M. S. ;Khan, A. ;Yang, J. W. ;Simin, G. ;Ping, A. ;Adesida, T.

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 139 KB
• Volume: 176
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/(sici)1521-396x(199911)176:1<201::aid-pssa201>3.0.co;2-l

✦ Synopsis

Experimental results of the low-frequency noise measurements on a large number of different AlGaN/GaN High Electron Mobility Transistors (HEMTs) grown on sapphire and SiC substrates have been presented. In the HEMTs grown on sapphire, the 1af noise is an order of magnitude (or more) higher than for AlGaN/GaN HEMTs grown on SiC substrates. The devices on SiC substrates also have higher electron mobility compared to the devices grown on sapphire substrates. The temperature dependence of noise reveals a contribution to the noise from a local level with activation energy of approximately 0.42 eV for the structures grown on sapphire. A very weak temperature dependence of the low-frequency 1af noise found for the wafers grown on SiC is very important for high temperature applications of these devices.