We have used reflection high‐energy electron diffraction (RHEED) to study the surface recovery of AlGaAs under different conditions. A modified process for growth interruptions was then introduced, where a GaAs monolayer was grown at each growth stop, and the arsenic flux was turned off during the low‐temperature phase of growth interruptions. Selectively doped inverted heterojunctions were grown using the modified growth interruptions together with low‐growth temperature (to avoid Si and impurity segregation). This combined process gave reproducible electron mobilities as high as 460 000 cm2/V s with sheet carrier concentration of 2×1011cm−2at 4.2 K.