Advantage of short over long annealing to activate As implanted in metastable pseudomorphic Ge_0.08Si_0.92 layers on Si(100)

Metastable pseudomorphic Ge_0.08Si_0.92 layers grown by chemical-vapor deposition on Si(100) substrate were implanted at room temperature with 90 keV As ions to a dose of 1×10¹³ cm^-2. The samples were subsequently annealed for short 40 s durations in a lamp furnace with a nitrogen ambient, or for long 30 min periods in a vacuum tube furnace. For samples annealed for a 30-min-long duration at 700°C, the dopant activation can only reach 50% without introducing significant strain relaxation, whereas samples annealed for short 40 s periods (at 850°C) can achieve more than 90% activation without a loss of strain. We conclude that it is advantageous to anneal a low-dose As-implanted pseudomorphic and metastable GeSi epilayers briefly at an elevated temperature, rather than to anneal it for a 30-min-long period at a lesser temperature, when high activation without a strain loss is desired.