Investigation on optical and electrical properties of LPCVD SiO/sub x/N/sub y/ thin films

Amorphous silicon oxynitride (a-SiO/sub x/N/sub y/) films of various compositions were deposited by low-pressure chemical vapour deposition (LPCVD) at temperature range of 820-880/spl deg/C and 400 mTorr, using mixture of SiCl/sub 2/H/sub 2/-NH/sub 3/N/sub 2/O. The investigation on optical and electrical properties was made using spectroellipsometry (SE) and the analyses of 1 MHz capacitance-voltage characteristics. To calculate optical and microstructural parameters of the films we used different approaches (Bruggeman-EMA, Cauchy, Sellmeier and Wemple-Di Domenico). The observed low densities of the interface traps are attributed to the nitrogen incorporation at the SiO/sub x/N/sub y//Si interface which leads to suppression of their generation.