Falling down capacitance impedance under light illumination of MDS-structures with three-layer SiNx dielectrics

ABSTRACT Characterisation of three-layer dielectric embedded into MDS-structure (Metal-Dielectric-Silicon) was provided in the dark and under light illumination. In the dark, increasing of differential capacitance, simultaneously, with variation of differential conductivity of MDS-structures was detected. In the light strong changing of capacitance part of impedance was firstly observed, demonstrating decreasing almost to zero values and restoring up to maxim al values in narrow bands of voltage applied. Variation of capacitance exceeds significantly so called dielectric layer capacitance, what interpreted as carriers exchanging between substrate and electronic states in SiN x probably due to three-layered kind of its nature. Keywords: silicon nanocrystals, non-volatile memory, Raman scattering, photoluminescence 1. INTRODUCTION Attraction of silicon nanocrystals connected with their possible application in non-volatile memory. Earlier, laser treatment was shown to be a useful tool for modification of Si clusters in silicon nitride films, been deposited by pyrolytic decomposition method [1]. In this work we investigated silicon-nitride films with silicon clusters produced by plasma-chemical vapor deposition technique. This deposition technique provides essentially lower deposition temperatures, what could be important for some applications, in particular, for flat display technologies. Equipping flat display with memory elements made within on-chip low temperature technology looks very promising for further development in this area. Moreover, varying band gap of SiN