Low-frequency noise characteristics of lattice-matched (x=0.53) and strained (x>0.53) In0.52Al 0.48As/InxGa1-xAs HEMT´s

Extensive bias-dependent and temperature-dependent low-frequency (LF) noise measurements were performed on lattice-matched and strained In_0.52Al_0.48As/In_xGa_1-x As(0.53<x<0.70) HEMTs. The input-noise voltage spectra density is insensitive to V_DS bias and shows a minimum at V_GS corresponding to the peak g_m condition. The corresponding output-noise voltage spectral density, which depends strongly on the gain of the devices, increases with V_DS. The input noise was rather insensitive to indium (In) content. Temperature-dependent low-frequency noise measurements on these devices reveal shallow traps with energies of 0.11, 0.15, and 0.18 eV for 60%, 65%, and 70% In HEMTs. Noise transition frequencies for these devices were on the order of 200-300 MHz and remain almost the same for different channel In content and V_DS bias