Interface Roughness Fractality Effects on the Electron Mobility in Semiconducting Quantum Wells

The influence of interface electron scattering on electron mobility in semiconducting quantum wells is analyzed theoretically in the Born approximation. The interface roughness is assumed to be random self-affine fractal characterized by roughness exponent H, correlation length ξ, and rms amplitude Δ. In particular, the ratio of electron mobilities for the Fermi level slightly above and below the second miniband edge (or for the well width above and below a critical width dc for a constant areal electron density) is calculated. It is shown that the correlation length ξ and roughness exponent H have pronounced effects on electron mobility.