An IR spectroscopic study of silicon oxynitride films

Correlated to the ever shrinking dimension of the nowadays electronic devices and since the electronic factories try to stick at the silicon technology as long as possible new problems arise. One of these problems is the breakdown of the gate-oxide function of silicon dioxide layers at the necessarily small thickness of few nanometers and below. The main reasons of the failure of such silicon oxide are tunneling of charge carriers and diffusion of dopands through the ultrathin layer. The disadvantage of the SiO₂ may be overcome by inserting nitrogen atoms into the silicon-dioxide network. To do this with sufficient lateral homogeneity is a nowadays challenge for deposition and control. We report on an infrared spectroscopic study of silicon oxynitride films with respect to the lateral variation of the chemical composition on a silicon wafer.