Thermally stable GaN RF HEMTs on proton irradiated GaN substrates for low-noise applications

In this study, proton irradiation is employed to fabricate semi-insulating GaN free-standing wafers with a sheet resistance of 5.9 × 107 Ω/sq. The mechanism for achieving semi-insulating GaN via proton irradiation is associated with the formation of a deep-level trap (EC-0.54 eV), which is tentatively attributed to nitrogen antisite-related defects (NGa). GaN-on-GaN high electron mobility transistors fabricated on the irradiated substrates exhibit stable operation over 300–375 K, with a minimum noise figure as low as 0.25 dB, with suppressed low-frequency noise characteristics. Additionally, the proton irradiation treatment GaN substrate also exhibits high volume production potential. This device is ideal for installation in harsh operational environments, such as satellite communication systems or outdoor base stations.