PURPOSE: To obtain a semiconductor crystal containing activated impurities with uniform density by growing a ZnSe crystal from a soln. containing specified impurity elements by a liquid phase method, dipping the obtd. crystal in a Zn soln., and heat treating the crystal.

CONSTITUTION: A ZnSe crystal is obtd. from a soln. contaning elements of group III to VII as impurities by ≤0.5mol% by a liquid phase growing method. The obtd. crystal is dipped in a Zn soln. and heat treated at ≥600°C to activate the impurities. Thus, a semiconductor crystal incorporated with impurities is obtd. If the impurity is aluminum, the temp. for heat treatment is preferably ≥600°C. By this method, since the ZnSe crystal grown from the soln. is preliminarily doped with impurities, the density of impurities in the depth direction of the crystal can be made uniform. By heat treating the crystal in the Zn soln., impurities can be effectively activated.