Influence of Al mole fraction on the noise performance of GaAs/Al/sub x/Ga/sub 1-x/As HEMT's

By using a Monte Carlo particle simulation, the influence of the Al mole fraction on the intrinsic noise properties of GaAs/GaAs HEMT's is analyzed. P, R, and C noise parameters and the minimum intrinsic noise figure are calculated. The results reveal that the decrease of the energy barrier at the heterojunction as the Al mole fraction is reduced (which leads to a closer approach of the electrons to the gate electrode) makes the noise associated to this electrode increase, consequently degrading the noise performance of the device.