SiCN films: preparation, properties and practical application (review)

Abstract

Si-CN films exhibit high mechanical and optoelectronic properties such as photoconductivity, photoluminescence, variable energy gap in the range of 1.37-5.2 eV, high mechanical and thermal strength, low thermal expansion, which allows them to be used in semiconductor devices. and in microelectronic mechanical systems. They are obtained by chemical deposition methods, and to activate the reaction using thermal heating, plasma or ultraviolet radiation, and by physical methods of deposition at relatively low temperatures by magnetron sputtering. The structure of the films can vary from microcrystalline to amorphous, the main influence being the deposition temperature. Chemical bonding in films is carried out mainly due to the interaction of Si-N, Si-C, C-C, C-N. Despite a significant amount of experimental work to study the properties of Si-C-N films, there are virtually no studies of films deposited by plasma chemical methods using hexamethyldisilazane as the main precursor. The review analyzes the influence of the main parameters of plasma chemical deposition, such as substrate temperature, reagent flow rate, high-frequency discharge power and displacement on the substrate on the physical properties of the films. It is shown that the main mechanism of transport of charge carriers in the investigated films is the space charge limited current. Based on electrical measurements, a number of band parameters as well as parameters of deep traps in a-SiCN films were estimated for the first time.