Group III Dopants

White and Christie used SIMS and RBS to measure dopant profile broadening caused by pulsed laser annealing (47). They also observed the incorporation of Group III-V dopants in Si at levels exceeding previously accepted solid solubility limits. Non-substitutional species, like Fe, were not incorporated in the Si but were segregated to the surface. 

Doping by group III elements allows for the substitution of Zn and thus, for the creation of one electron per dopant atom. 

The ionisation energies of the electronically active impurities have been determined primarily by photoluminescence techniques and Hall measurements. Ionisation energy levels of such impurities as nitrogen and some of the group III elements (aluminium, gallium, boron) in 3C-, 4H-, 6H- and 15R-SiC polytypes are compiled in TABLE 2. Nitrogen gives relatively shallow donor levels. In contrast, other p-type dopants have deep-level acceptor states. 

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