Post-growth annealing was used to reduce the threading dislocation density of Hg1-xCdxTe epilayers (where x was between 0.20 and 0.28) which had been grown onto (211)B GaAs substrates by means of molecular beam epitaxy. Etch-pit methods revealed the occurrence of an order of magnitude reduction in the number of surface threading dislocations after annealing (490C, 0.5h). It was noted that the dislocation density at the (Cd,Hg)Te surface of the highly mismatched system was only 2 to 6 times higher than the best values (105/cm2) which had been obtained by using (Cd,Zn)Te bulk lattice-matched substrates. The reduction in the number of dislocations was attributed to enhanced dislocation movement and to their annihilation and coalescence at Hg vacancy pinning centers which had been introduced during annealing.

J.M.Arias, M.Zandian, S.H.Shin, W.V.McLevige, J.G.Pasko, R.E.DeWames: Journal of Vacuum Science and Technology B, 1991, 9[3], 1646-50