Low temperature (2 K) photoluminescence (PL) properties of epitaxial Si1-x-yGex 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 investigated. Samples were prepared by a high-dose Ge with/without C ion implantation (I2) at room temperature and by subsequent three different crystallization techniques: (i) furnace annealing (FA) process up to 840°C, (ii) ion beam-induced epitaxial crystallization (IBIEC) process with 400 keV Ge or Ar ions at 300-350°C, and (iii) IBIEC process followed by FA process up to 640°C (IBIEC + FA). Although FA-grown Si1-x-yGexCy samples showed G-line (Cs-Sii-Cs complex) emission at 0.969 eV, IBIEC-grown samples presented a sharp I1 non-phonon emission at 1.0193 eV. This indicates that C atoms agglomeration is dominant for FA-grown samples, while a creation of trigonal tetravacancy 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 I1-related emissions, which indicates that good crystalline Si1-x-yGexCy layers without C agglomeration were formed by this process. In contrast, (IBIEC with Ar ions + FA)-grown samples exhibited novel successive PL vibronic sidebands at 0.98-1.03 eV. From their excitation power dependence measurements, they were found to be associated with exciton bound to defects levels created by Ar+ bombardment.
|ジャーナル||Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms|
|出版ステータス||Published - 1997 1|
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