A new type of thermal treatment for air‐exposed AlGaAs surfaces,insitulow‐temperature H2annealing, has been developed regrowing AlGaAs in metalorganic vapor phase epitaxy. The quality of regrown interface was evaluated by photoluminescence (PL) spectrum from Al0.3Ga0.7As/GaAs/Al 0.3Ga0.7As quantum wells near the interface of the initial AlGaAs layer. Remarkable recovery of PL intensity was observed by this newly developed process, indicating that initial air‐exposed AlGaAs surface states are reduced. ©1996 American Institute of Physics.