Optical properties of multilayer SiNx/SiNy structures prepared by plasma-enhanced chemical vapor deposition

Abstract

We have investigated the optical properties of multilayer SiNx/SiNy structures deposited on Si(100) substrate by using rf-PECVD (plasma, enhanced chemical vapor deposition). In order to fabricate the nanostructures, the single- and multi-layered SiNx/SiNy structures with various oxygen and nitrogen compositions were prepared and rapid thermal annealing process was subsequently employed with ex-situ procedure. The formations of nanostructure Si were confirmed by measurements bu using atomic force microscopy (AFM). Particularly, the peak energy of photoluminescence was varied as a result of changing the nitrogen composition and the annealing temperatures. The visible emission wavelengths from blue to red in PL spectra were observed although all luminescent bands were not always in correspondence with the size effects. This indicates that the origins of the emission mechanism from the nanostructures cannot be simply figured out from the quantum size effects. Thus, other effects such as interface states and defects were considered as origins.