Optical and Structural Properties of Silicon Nanocrystals Embedded in SiO x Matrix Obtained by HWCVD

The interest in developing optoelectronic devices integrated in the same silicon chip has motivated the study of Silicon nanocrystals (Si‐ncs) embedded in SiO x (nonstoichiometric silicon oxides) films. In this work, Si‐ncs in SiO x films were obtained by Hot Wire Chemical Vapor Deposition (HWCVD) at 800, 900, and 1000°C. The vibration modes of SiO x films were determined by FTIR measurements. Additionally, FTIR and EDAX were related to get the proper composition of the films. Micro‐Raman studies in the microstructure of SiO x films reveal a transition from amorphous‐to‐nanocrystalline phase when the growth temperature increases; thus, Si‐ncs are detected. Photoluminescence (PL) measurement shows a broad emission from 400 to 1100 nm. This emission was related with both Si‐ncs and interfacial defects present in SiO x films. The existence of Si‐ncs between 3 and 6 nm was confirmed by HRTEM.