Temperature Dependence of Electron Mobility in InGaAs/InAlAs Heterostructures

Abstract

Temperature dependence of the electron mobility in modulation-doped InGaAs/InAlAs single heterostructures has been investigated by Hall effect measurements in the temperature range from 15 K to 300 K in order to clarify the scattering mechanisms of the electrons. Two kinds of samples are used with doping densities in the InAlAs barrier layer, N D=3×1017 cm-3 and 1×1018 cm-3. The measured electron mobility is compared with the calculated values by taking into account the scattering by InAs-like and GaAs-like LO phonons in the InGaAs channel layer, in addition to the acoustic deformation potential, piezoelectric, ionized impurity, alloy disorder and interface roughness scatterings. The calculated electron mobility shows a good agreement with the experimental data when the alloy disorder potential is assumed to be about 0.7 eV.

ELECTRON SCATTERING IN BURIED InGaAs/HIGH-K MOS CHANNELS

“…3. The samples with deeply buried (d=50 nm) QW channel shows µ~T -1.1 trend, which is close to µ~T -1.2 typically observed in n-type InGaAs QWs in the 80-300K temperature range [14] with the main contribution from polar optical phonon scattering and some effect of almost temperatureindependent alloy disorder and hetero-interface roughness scattering. The samples with thinner top barriers show the reduced slope of the curves and eventually reversed slopes in the samples with d<3nm.…”

Two-dimensional electron gas in InGaAs∕InAlAs quantum wells

“…Moreover, since the dependence of the mobility on the 2DEG density is very weak as seen in Table I, we believe that an important source of scattering is due to the random alloy scattering potential, which is expected to have a weak density dependence [24]. Such intrinsic alloy scattering is clearly very important in the In 0.53 Ga 0.47 As channel, as claimed previously to dominate the low temperature scattering in InGaAs/InAlAs heterojunctions [13,15]. We further believe that surface roughness is less important since these structures are lattice matched MBE grown and because surface roughness would lead to a stronger dependence of mobility on density.…”

“…It is also an attractive 2DEG system for the study of disorder induced quantum phase transitions [6,7,8,9,10,11]. While there have been several earlier works characterizing electronic properties of 2DEGs in In 0.53 Ga 0.47 As/In 0.52 Al 0.48 As heterojunctions [12,13,14,15], In 0.53 Ga 0.47 As/InP heterojunctions and quantum wells (QW) [16,17,18], there were few systematic studies characterizing 2DEGs in In 0.53 Ga 0.47 As/In 0.52 Al 0.48 As QWs. Since many modern structures [1,2,3,5] are now based on In 0.53 Ga 0.47 As/In 0.52 Al 0.48 As QWs, such characterization is of fundamental and technological interest.…”

Physics and Mitigation of Excess OFF-State Current in InGaAs Quantum-Well MOSFETs

“…Recombination in the body of the channel and the cap is neglected because the carrier diffusion lengths in these two regions are estimated to be much longer than the gate length and the cap thickness, respectively. This estimation is based on the experimental carrier lifetimes of In 0.53 Ga 0.47 As/InP structures [18] and reasonable mobilities [19], [20], and yields a diffusion length that is over 10 μm in the channel and ∼0.2 μm in the n + cap. Nevertheless, we explore the effect of carrier recombination in the body of the semiconductor in Section V.…”