AGGREGATE DEFECTS OF GOLD AND PLATINUM WITH LITHIUM IN SILICON .1. MAGNETIC-RESONANCE INVESTIGATIONS

Trigonal and orthorhombic An (Pt) defects in Si additionally doped wit h Li and P, previously investigated with electron paramagnetic resonan ce (EPR), are shown to be aggregate defects involving substitutional A u (Pt) and interstitial Li. The small Li hyperfine interactions, not r esolved in EPR, could be measured with electron nuclear double resonan ce (ENDOR). With double ENDOR it is established that the trigonal defe cts consist of Au-si-Li-3 (Pt-si-Li-3) aggregates, while the orthorhom bic defects are Au-si-Li (Pt-si-Li) pair defects. For the trigonal def ects the Li hyperfine interaction matrices are asymmetric. The smallne ss of the Li hyperfine interaction suggests ionic bonding between the interstitial Li ions and the substitutional Au-si (Pt-si) atoms.