INTERDIFFUSION BEHAVIOR OF HG IN HGTE CDTE SUPERLATTICES GROWN ON CD0.96ZN0.04TE (211)B SUBSTRATES BY MOLECULAR-BEAM EPITAXY/

Double-crystal x-ray rocking curve (DCRC) and secondary-ion mass-spect roscopy (SIMS) measurements have been performed to investigate the eff ect of rapid thermal annealing on the interdiffusion behavior of Hg in HgTe/CdTe superlattices grown on Cd0.96Zn0.04Te (211)B substrates by molecular beam epitaxy. The sharp satellite peaks of the DCRC measurem ents an a 100-period HgTe/CdTe (100 Angstrom/100 Angstrom) superlattic e show a periodic arrangement of the superlattice with high-quality in terfaces. The negative direction of the entropy change obtained from t he diffusion coefficients as a function of the reciprocal of the tempe rature after RTA indicates that the Kg diffusion for the annealed HgTe /CdTe superlattice is caused by an interstitial mechanism. The Cd and the Hg concentration profiles near the annealed HgTe/CdTe superlattice interfaces, as measured by SIMS, show a nonlinear behavior for Hg, or iginating from the interstitial diffusion mechanism of the Hg composit ion. These results indicate that a nonlinear interdiffusion behavior i s dominant for HgTe/CdTe superlattices annealed at 19 degrees C and th at the rectangular shape of HgTe/CdTe superlattices may change to a pa rabolic shape because of the intermixing of Hg and Cd due to the therm al treatment.