A new AlGaAs layer was formed on GaAs substrates by Zn implantation into an Al0.4Ga0.6As single heterointerface. The Zn implantation of 1015cm−2doses at 200 keV with subsequent annealing at 500 °C for 15 min formed the AlxGa1−xAs layer (x<0.4) graded compositionally to the depth with the thickness of about 300 A˚. AlGaAs fine patterns of 2–10 &mgr;m wide were formed on GaAs substrates by Zn implantation and with low‐temperature, short‐time annealing.