Paramagnetic point defects at SiO2/nanocrystalline Si interfaces

A K- and Q-band electron spin resonance study, combining two detection modes, on structures composed of Si nanoparticles (similar to 2 nm across) embedded in a SiO2 matrix obtained by annealing of SiO/SiO2 superstructures unveils the observed principal Si dangling bond signal as solely comprised of the intrinsic P-b(0) and P-b1 Si/SiO2 interface defect spectra, of comparable densities. Based on independent particle density counting, about one P-b-type defect is found at every 1.4 Si nanoparticles. Relying on the known properties of P-b-type defects in standard microscopic Si/SiO2, the data would comply with Si nanocrystallites with morphology, schematically, of [100] truncated (111) octahedrons. Both types and densities of observed point defects indicate a structure of quality much alike that of standard thermal Si/SiO2. (C) 2008 American Institute of Physics.