FTIR, AFM and PL properties of thin SiOx films deposited by HFCVD

In order to have optoelectronic functions integrated in a single chip, it is very important to obtain a silicon compatible material with an optimal photoluminescence response. The non-stoichiometric silicon oxide (SiOx) has shown photoluminescence response and is also compatible with silicon technology. In this work, the composition and optical properties of the SiOx films are studied using null ellipsometry, Fourier transformed infrared spectroscopy (FTIR), atomic force microscopy (AFM), and photoluminescence (PL). The SiOx films were growth to different temperatures. The IR absorption spectrum shows the presence of three typical Si–O–Si vibrations modes in SiO2. However, changes in their intensity and position were observed. Also, when growth temperature decreased, the Si–H vibrations modes were observed. These changes are directly related with compositional variation in the SiOx films due to the growth temperature. A PL spectrum shows a considerable emission in the range 400–850 nm that varies with the growth temperatures.