STRUCTURAL CHARACTERIZATION OF HEAVILY ZN-DOPED LIQUID ENCAPSULATED CZOCHRALSKI INP

A structural characterization of liquid encapsulated Czochralski InP h eavily doped with Zn is presented. At a hole density as high as 3.0 x 10(18) cm(-3), corresponding to a Zn content of 10(19) atoms cm(-3), t he crystals are dislocation-free. They contain, however, a high densit y (ca. 7 x 10(9) cm(-3)) of precipitates identified as Zn3P2 by electr on diffraction. This supports the model in which Zn in excess of that occupying Ln sites as electrically active acceptor can react with the group V element to form precipitates. Other possible lattice locations of the excess Zn cannot be checked by our techniques. The Zn3P2 preci pitates tend to disappear for a hole concentration of 2.6 x 10(18) cm( -3), but dislocations are generated since the hardening effect associa ted with dopant atoms decreases. The majority of the dislocations have climbed, leaving behind a local high density of microdefects. The pos sible mechanisms for the generation of these microdefects are discusse d.