Vacancy-oxygen defects in p-type Si1−xGex

Oxygen-vacancy defects and, in particular, the VO pairs (known as A-centers) are common defects in silicon (Si) with a deleterious impact upon its properties. Although oxygen-vacancy defects have been extensively studied in Si there is far less information about their properties in p-type doped silicon germanium (Si1−x Ge x). Here, we use Fourier transform infrared spectroscopy to determine the production and evolution of oxygen-vacancy defects in p-type Si1−x Ge x. It was determined that the increase of Ge content affects the production and the annealing behavior of the VO defect as well as its conversion to the VO2 defect. In particular, both the VO production and the VO annealing temperature are reduced with the increase of Ge. The conversion ratio [VO2]/[VO] also decreases with the increase of x, although the ratios [VO3]/[VO2] and [VO4]/[VO3] show a tendency to increase for larger Ge contents. The results are discussed in view of recent experimental and theoretical studies in Si and Si1−x Ge x. Publisher statement: Copyright 2014 AIP Publishing. This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. The following article appeared in Sgourou, E.N. , Londos, C.A. and Chroneos, A. (2014) Vacancy-oxygen defects in p-type Si1−xGex. Journal of Applied Physics, volume 116 (Article number 133502) and may be found at http://scitation.aip.org/content/aip/journal/jap/116/13/10.1063/1.4896728