Channel sensitivity to gate roughness in a split-gate GaAs-AlGaAs heterostructure

The response of the width of the electron channel at a GaAs-AlGaAs heterointerface to variations in the gate opening of a split-gate structure is calculated using a three-dimensional solution of the Poisson equation in the continuum approximation and is analyzed in terms of the Fourier components of the perturbation. It is found that the effective potential well for the channel electron gas attenuates high wave vector components of the gate roughness.