In silicon dopants diffuse via interactions with native point defects. This concept is now generally accepted relying on experimental observations and theoretical calculations [20,21]. The focus of this work is put on interactions with the simple native point defects: interstitial (I) and vacancies (V). A vacancy is an empty lattice site, while an interstitial is a host atom present on a site different from a regular substitutional lattice site.
In the following sections the possible reactions between dopant atoms and native point defects are described. The dopant atom is always denoted as and, correspondingly, a vacancy-dopant pair as , and an interstitial-dopant pair as .
Simple point defects and point defect pairs exists in different charge states. The reactions between charged species and current carriers are expressed by the following relationships for the case of electrons (),
The system in which a dopant diffuses via interactions with point
defects can be described by the following set of reactions. We take as example a
reaction with an ionizated donor atom:
dopant-defect pairing reactions,