Applied Physics Letters · 2004 · 28 citations · 15 references
EngineeringMaterials SciencePhysicsCondensed Matter PhysicsSemiconductor DevicesSemiconductor MaterialsCarrier TransportQuantum ConfinementQuantum WellsSemiconductor InterfacesSemiconductor PhysicsSemiconductor SurfacesCarrier Transport In Quantum WellsHall EffectInterface Roughness ScatteringReflectivityRoughness ParametersStrain EffectsTransport In Quantum WellsX-ray Reflectivity
We studied in-plane transport of a two-dimensional hole gas in modulation-doped p-Si0.2Ge0.8 quantum wells (QWs) on Si0.5Ge0.5 relaxed buffer substrates with thicknesses L between 2.5 and 7 nm. We found that interface roughness scattering limits the low-temperature mobility μ of the samples with L between 2.5 and 4.5 nm. The interface roughness parameters were evaluated by fitting the experiment with the calculated μ limited by interface roughness scattering. We found that the obtained parameters were consistent with the values estimated from x-ray reflectivity and the transmission electron micrograph of the samples. When L is increased from 4.5 to 7 nm, μ increases only gradually and the highest μ of 0.44 m2/V s was observed for 7-nm-thick QWs. The scattering by defects, interface charge, and strain fluctuation are discussed as possible additional mobility-limiting mechanisms.
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High-mobility Si and Ge structures
F. Schäffler · Semiconductor Science and Technology · 1997 · 765 citations
Interface roughness scattering in GaAs/AlAs quantum wells
H. Sakaki, Takeshi Noda, Kazuhiko Hirakawa et al. · Applied Physics Letters · 1987 · 680 citations