Cathodoluminescence of Silicon Rich Oxide with nitrogen incorporated

Abstract

Cathodoluminescence (CL) spectra for Silicon Rich Oxide (SRO) films with different silicon excess and nitrogen content are measured at room temperature. The SRO was deposited by Low Pressure Chemical Vapor Deposition (LPCVD) on Si substrates, and nitrogen was introduced into SRO adding NH3 to the reactive gases. The samples were divided in two parts, one part was annealed at 1100degC. The nitrogen incorporation was observed by Fourier Transform Infrared Spectroscopy (FTIR). All samples annealed at 1100degC show CL, and only SRO with low silicon excess shows emission as deposited. The CL emission shows bands centered at ~460 nm, ~530 nm and ~720 nm. The emission of these bands depends on nitrogen and silicon excess. The peak of the blue CL band (~460 nm) is related to twofold coordinated silicon center (=Si:). The band at ~530 nm is related with defect due to nitrogen incorporation. The band at ~720 nm band is similar to that obtained in PL.