Identification of a paramagnetic recombination center in silicon/silicon-dioxide interface

A paramagnetic recombination center having an orthorhombic symmetry with g [110]=2.0095(2), g [001]=2.0038(2), and g [ 1 ¯ 10 ] =2.0029(2) is found at the interface between silicon and native oxide. The center is referred to P m center and observed by a spin dependent recombination based electron paramagnetic resonance detection that has the sensitivity of ∼10 11 spins/cm 2 . The employment of an isotopically enriched 28 Si sample with the concentration of 29 Si nuclear spins reduced to 0.017% leads to narrowing of the resonance line. This narrowing is the key for the accurate determination of the angular dependence of the g-factor.