1/ƒ and g-r noise in AlGaAs epitaxial layers

Abstract Low frequency noise measurements have been performed in Al x Ga 1− x As test structures with x = 0.25 and x = 0.20 at 300 K. For samples with x = 0.25 the excess noise spectra show two Lorentzian shaped g-r contributions and 1/ƒ noise and with x = 0.20 the main noise source is a 1/ƒ component. The results are analysed as a function of the sample length in order to distinguish between bulk and interface noise contributions.