Hooge parameter of InGaAs bulk material and InGaAs 2DEG quantum well structures based on InP substrates

The 1/f noise of various InGaAs layers lattice matched to InP is investigat ed systematically at room temperature. To elucidate the origin of the 1/f n oise in this type of III-V compound semiconductor, thick n-type doped InCaA s layers, typical InP based InAlAs/InGaAs or InP/InGaAs heterostructure hel d-effect transistor (HFET) structures, respectively, as well as InP based I nAlAs/InGaAs quantum well structures with doped InCaAs two-dimensional elec tron gas (2DEG) channel are analysed. From the experiments it is found that mobility fluctuation is the only origin for the 1/f noise observed both in InGaAs bulk material and in 2DEG heterostructures of high quality. A Hooge parameter attributed to phonon scattering alpha (Hphon) in the bulk materi al is found to be about 7 x 10(-6) and agrees with those obtained from HFET structures with the highest mobilities (alpha (H) x 1.5 x 10(-5)). Further more, the Hooge parameter of 2DEG structures strongly depends on the channe l design and on the doping concentration in the n-type doped 2DEG channels. (C) 2000 Elsevier Science Ltd. All rights reserved.