Electroluminescence of Si quantum dots in MOS structures

We have studied the structural, electrical and optical properties of MOS devices, where the dielectric layer consists of a substoichiometric SiOx (x < 2) thin film deposited by plasma enhanced chemical vapor deposition. After deposition the SiOx samples were annealed at 1250 degreesC for I h; the thermal treatment induces the separation of the Si and SiO2 phases with the formation of Si nanocrystals embedded in the insulating matrix. We observed at room temperature a quite intense electroluminescence signal that is attributed to emission from silicon nanocrystals. The effects of the Si concentration in the SiOx layer on the electrical and optical properties of these devices are reported and discussed.