Generation of delocalized E′δ defects in buried Si oxide by hole injection

Abstract

The generation of delocalized E′δ defects through hole injection in buried SiO2 (BOX) layers of standard separation-by-implantation-of-oxygen structures has been studied by electron spin resonance. Selective photoinjection of holes was carried out under positive biasing of deposited semitransparent electrodes. This leads to the production of numerous delocalized E′δ centers (density≊1.8×1013 cm−2) in addition to a large density (∼9×1013 cm−2) of the common E′γ defect (O3≡Si⋅+Si≡O3)—a result qualitatively similar to previous glow discharge damage data. Comparison of damaging agents applied to BOX indicates that E′γ and E′δ defects are generally produced in an approximately fixed relative ratio. The comparison further bears out that, while energetic photons (x and γ) and ion bombardment activate similar E′δ defects of axial symmetry, hole injection generates a more isotropic type, termed E′δ2. It reveals the tendency that as the damaging species gets ‘‘softer,’’ the g matrix anisotropy fades together with the disorder-induced g spread.