Electron scatterings in selectively doped $n-AlGaAs∕GaAs$ heterojunctions with high density self-assembled InAlAs antidots

The scattering processes of two-dimensional electrons are studied in selectively doped $n-AlGaAs∕GaAs$ heterojunctions where high density InAlAs anti dots are embedded in the vicinity of the GaAs channel. Mobilities $μ$ are measured as a function of the electron concentrations $Ns$ in two samples where the $In1−xAlxAs$ antidots are grown with different Al contents (⁠$x∼0.75$ and 0.5). It is found that the $Ns$ dependence of $μ$ is strongly dependent on the Al content $x$ of the embedded InAlAs dots, although their shapes and densities are almost same. The experimental data are well explained by theoretical models based on the surface profiles of the InAlAs dot layers.