Characterization of impurities and defects by electron paramagnetic resonance and related techniques

Abstract

The use of electron paramagnetic resonance (EPR and ENDOR) in the study of defects in semiconductors is briefly reviewed, including group IV (C-diamond, Si, Ge, SiC), III-V (AlSb, GaAs, GaSb, GaP, InAs, InP, InSb), II-VI (BaO, BaS, BeO, CaO, CaS, CaSe, CdO, CdS, CdSe, CdTe, MgO, SrO, SrS, ZnC, ZnS, ZnSe, ZnTe) and miscellaneous systems. The identification of defects via EPR is described as is the exploitation of that identification as a tool in future studies. Particular attention is paid to Si. In the category of defect identification in silicon there is emerging an integrated panorama of identified defects ranging from point defects to their complexes and aggregates to so-called intermediate defect configurations on to dislocations and stacking faults. In addition impurities and their interactions are discussed, including mention of a possible origin of the so-called oxygen shallow donor and of the understanding of hydrogen in silicon. As examples of EPR studies as a tool in defect studies the concentration dependence of the phosphorus resonance is described from the regime of isolated defects to the metallic regime. The ENDOR results on defects in silicon are discussed at some length, and it is emphasized that even for the shallow donors there is far from a satisfactory theoretical treatment of the data, and that the situation is even worse for other defects in silicon.