Characteristics in the motion of dislocations generated from scratches in GaAs doped with In at a concentration of 2×1020atoms/cm3are investigated and are compared with those in undoped GaAs. &agr; dislocations in In‐doped GaAs are found to be immovable under stress lower than 10 MPa in the temperature range 350–750 °C. Such immovability under low stress is not found for &bgr; dislocations in In‐doped GaAs and for both &agr; and &bgr; dislocations in undoped GaAs.