| Abstract: | A consequent application of dopant incorporation theory to epitaxial silicon layer growth above buried layer regions explains the formation of an exponentially decaying dopant profile not only above that buried layer but also beyond of it. Taking into account desorption of dopants only and and neglecting readsorption of dopants on buried layer regions allows one to describe both vertical redistribution autodoping and lateral autodoping by the well known exponential expression that originally has been derived by Reif et al. in order to describe intended non-steady state doping behaviour and later applied to lateral autodoping by Wong and Reif. Doping incorporation theory also explains the formation of a near-equilibrium surface coverage with adsorbed dopants outside of buried layer during a preepitaxial baking process. Different dopant sources contributing to autodoping are characterized by different time constants. In this connection the adsorbed layer model derived by Tabe and Nakamura could be related to the action of two different dopant sources of autodoping where one of the two is characterized by a time constant being nearly infinite in number. |
