Control of The Sb Redistribution in Strained SiGe Layers Using Point Defect Injection

Abstract

AbstractSb diffusion in strained Si1−xGex (x = 0.1 and 0.2) layers during nitridation (in NH3, 810 °C) and oxidation (in dry O2, 825 and 900 °C) of Si/Si1−xGex/Si heterostructures is measured and, subsequently, compared with that obtained for treatments in vacuum. An enhancement (ν) or retardation (η) of Sb diffusion in strained Si1−xGex after nitridation/oxidation anneals is detected. For example, 810 (NH3) and 900 °C (O2) anneals results in ν ∼ 2 and η ∼ 0.15 in strained Si0.9Ge0.1, respectively. The retardation of Sb diffusion is attributed to the injection of excess self-interstitials (I) and strongly indicating low interstitialcy fraction of Sb diffusion in strained Si1−xGex. The enhancement of Sb diffusion may be due to direct injection of vacancies (V), but only if the V diffusivities are significantly different in Si and Si1−xGex, or depletion of I in the strained Si1−xGex layers caused by the excess V concentration at the top surface of silicon layer