DEEP LEVELS IN IN-DOPED CDTE EPITAXIAL-FILMS GROWN ON P-CDTE SUBSTRATES

Deep-level transient spectroscopy measurements have been carried out t o investigate the behavior of the deep levels existing in In-doped n-C dTe grown by molecular beam epitaxy on nominally undoped p-CdTe (211) B-orientation substrates. One electron-trap of the as-grown In-doped C dTe epilayer was observed, and the trap originated from complexes of C d vacancies and In impurities. After the In-doped CdTe epilayer was an nealed, one new trap at E-c -0.49 eV was observed, and the deep level was related to the Te vacancies or the Cd interstitials. These results indicate that the electron deep trap in In-doped CdTe epilayers is af fected remarkably by annealing and that the variation of the position of the deep level due to thermal treatment is a significant problem fo r electronic devices. (C) 1997 Elsevier Science B.V.