Flicker noise in GaN/Al/sub 0.15/Ga/sub 0.85/N doped channel heterostructure field effect transistors

Investigation of flicker noise and deep-levels in GaN/AlGaN transistors

“…Details of the structure parameters and fabrication process have been reported by us earlier. 2,3 With these two types of devices, we were able to carry out a comparative flicker noise study and elucidate the effect of doping on the noise level. In addition, we have studied GaN transistors fabricated on sapphire substrate.…”

“…1 We have also shown that GaN HFETs grown on sapphire can operate with low flicker noise levels, which are required for the microwave applications, particularly low-phase noise amplifiers. [2][3] The flicker noise, which manifests itself at low-frequencies (usually 0.01 kHz-100 kHz) with the 1/f γ spectral density dependence, is an important figure-of-merit for semiconductor devices since this type of noise is the limiting phase-noise factor for all kinds of transistors (γ is a parameter close to 1).…”

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

“…The values of a reported for the AlGaN HEMT structures grown on SiC substrate were much smaller (a % 10 À4 ) [7]. More recently, small values of a were reported for AlGaN/GaN HFETs grown on sapphire substrates [8]. A systematic investigation of the structures grown on different substrates using the same growth and fabrication technology might help to clarify the low-frequency noise properties of the AlGaN/GaN HFETs.…”

Effect of channel doping on the low-frequency noise in GaN/AlGaN heterostructure field-effect transistors

“…We have also shown that GaN HFETs grown on sapphire can operate with small low-frequency noise levels required for the microwave applications. 3 The Hooge parameter extracted for these devices was on the order of ␣ H Ϸ10 Ϫ5 -10 Ϫ4 which is comparable to the noise level in commercial GaAs devices.…”