PHOTOLUMINESCENCE STUDIES OF EPITAXIAL SI1-XGEX AND SI1-X-YGEXCY LAYERS ON SI FORMED BY ION-BEAM SYNTHESIS

Low temperature (2 K) photoluminescence (PL) properties of epitaxial S i1-xCex and Si1-x-yGexCy layers on Si (x = 0.13 and y = 0.014 at peak concentration) formed by ion beam synthesis (IBS) have been investigat ed. Samples were prepared by a high-dose Ge with/without C ion implant ation (I-2) at room temperature and by subsequent three different crys tallization techniques: (i) furnace annealing (FA) process up to 840 d egrees C, (ii) ion beam-induced epitaxial crystallization (IBIEC) proc ess with 400 keV Ge or Ar ions at 300-350 degrees C, and (iii) IBIEC p rocess followed by FA process up to 640 degrees C (IBIEC + FA). Althou gh FA-grown Si1-x-yGexCy samples showed G-line (C-s-Si-i-C-s complex) emission at 0.969 eV, IBIEC-grown samples presented a sharp I-1 non-ph onon emission at 1.0193 eV. This indicates that C atoms agglomeration is dominant for FA-erown samples, while a creation of trigonal tetrava cancy cluster is dominant for IBIEC-grown samples. On the other hand, (IBIEC with Ge ions + FA)-grown Si1-x-yGexCy samples showed neither G- line nor I-1-related emissions, which indicates that good crystalline Si1-x-yGexCy layers without C agglomeration were formed by this proces s, In contrast, (IBIEC with Ar ions + FA)-grown samples exhibited nove l successive PL vibronic sidebands at 0.98-1.03 eV, From their excitat ion power dependence measurements, they were found to be associated wi th exciton bound to defects levels created by Ar+ bombardment.