Minhan Chen and Wolfgang Porod We present numerical simulations for the design of gated delta-doped AlGaAs/GaAs quantum dot structures in the few-electron regime. The confining potential is obtained from the Poisson equation with a Thomas-Fermi charge model. The electronic states in the quantum dot are then obtained from solutions of the axisymmetric Schrödinger equation. Our model takes into account the effect of surface states by viewing the exposed surface as the interface between the semiconductor and air (or vacuum). We explore various gate configurations and biasing modes. Our simulations show that the number of electrons can be effectively controlled in the few electron regime with combined enhancement and depletion gates.