An empirical model of As surface segregation during reduced-pressure chemical vapor deposition Si epitaxy is presented. This segregation mechanism determines the resulting doping profile in the grown layer and is here described by a model of simultaneous and independent As adsorption and segregation versus incorporation. The model quantifies this mechanism with enough detail to be successfully applied to the accurate growth of different profiles, including the ascending x -2 doping profiles. For rapidly descending profiles the segregated As surface layer must be removed, e.g., by ex situ cleaning and Marangoni drying before further Si epitaxy.
- As doping
- Reduced-pressure chemical vapor deposition (RPCVD)
- Si epitaxy
- Surface segregation
- Varactor diodes