{311} defect evolution in Si-implanted Si1-xGex alloys

Molecular beam epitaxial (MBE), unstrained Si1-xGex layers of various Ge concentrations, ranging from 0% to 50%, were grown on top of a <100> Si substrate. The wafers were subjected to a 10 keV, 1 X 10(14) cm(-2) Si+ non-amorphizing implant. To study the defect morphology, the samples were annealed at 750degreesC for a total of 180 min. Plan-view transmission electron microscopy (PTEM) was utilized to observe and quantify the formation and dissolution of the defects. The Si1-xGex samples with less than or equal to 5% Ge exhibited {311} defect formation and dissolution; however, samples with Ge fractions greater than or equal to 25% showed only dislocation loop formation likely caused by a decrease in bond strength with increasing Ge content. (C) 2003 Elsevier Ltd. All rights reserved.