NEW STRAIN-RELIEVING MICROSTRUCTURE IN PURE-GE SI SHORT-PERIOD SUPERLATTICES/

High-temperature formation of highly strained pure-Ge/Si short-period superlattices (SPSs) and their photoluminescence (PL) properties are p resented. We grew 99 period SPSs consisting of two-dimensional Ge laye rs separated by thin Si barriers. The evolution of undulations is newl y observed for samples with small Si barrier thickness, which is attri buted to a strain-related growth phenomenon, and similarities to the w ell-established island formation are discussed. Clear band-edge PL is observed in these high-temperature grown SPSs, and interesting PL prop erties associated with the undulation formation are presented. (C) 199 8 American Vacuum Society.