Electronic structure of silicon oxynitride films grown by plasma-enhanced chemical vapor deposition for memristor application

Abstract

The electronic structure and optical properties of SiOxNy:H films enriched with silicon obtained by plasma-enhanced chemical deposition are studied. It is shown, that with the plasma generator power growth, the content of silicon (amorphous silicon clusters) and oxygen decreases, whereas the nitrogen content increases. Thus, the SiOxNy:H film composition can be effectively varied both by changing the gas flow ratio in the growth chamber and by changing the plasma generator power. The electronic stricture of SiOxNy of various x and y values is calculated from the first principles for the model structures, and the energy diagram, as well as the bandgap dependence on the oxygen content, is obtained. It is found that p+-Si/SiOxNy:H/Ni structures, have the properties of memristor bipolar type: they are reversibly switched between high and low resistance states. These memristors are forming-free: the initial state has a close resistance to the low resistance state.