A self‐limiting mechanism has been observed in the atomic layer epitaxy (ALE) of GaAs deposited by alternate exposure to AsH3and trimethylgallium (TMG). The thickness of the deposited film was found to be independent of the mole fractions of both TMG and AsH3in the gas phase. These results will allow the use of ALE to deposit III‐V compounds with growth rates which are insensitive to the input partial pressures of the reactive gases.