On the out-diffusion of oxygen from silicon

Abstract

Experimental results on the out-diffusion of oxygen from Si in the temperature range 900 to 1230°C are presented. For diffusion lengths ≦ 10 μm it is shown that the oxygen profiles for the Si samples investigated can be described by known theories of out-diffusion, where the temperature dependence of the diffusion coefficient as given by Haas is used in this temperature range. For diffusion lengths ≦ 10 μm an influence of the ambient atmosphere on the oxygen profiles could not be stated. Heat treatments at temperatures of about 450°C are shown to cause already a measurable out-diffusion of oxygen from Si. The analysis of profiles after 120 h heat treatment at 450°C yields a diffusion coefficient of D(450°C) ≈ 2.7 × 10−14 cm2 s−1.