A method of forming a SiOCN material layer, a material layer stack, a semiconductor device, a method of fabricating a semiconductor device, and a deposition apparatus, the method of forming a SiOCN material layer including providing a substrate; providing a silicon precursor onto the substrate; providing an oxygen reactant onto the substrate; providing a first carbon precursor onto the substrate; providing a second carbon precursor onto the substrate; and providing a nitrogen reactant onto the substrate, wherein the first carbon precursor and the second carbon precursor are different materials.