Defects in epitaxial SiGe-alloy layers

Examples of growth- and process-induced defects in strain-relaxed Si1−xGex alloy layers grown epitaxially on Si substrates are reviewed. Recent efforts to reduce the density of threading dislocations using different types of buffer layers to accommodate the misfit strain are examined, and the optical and electrical activity of growth-induced defects are discussed. As examples of process-induced defects, the vacancy, the di-vacancy, and the Sb-vacancy pair in n-type Si1−xGex are treated, and their thermal stabilities are discussed.