A bonding material stack for wafer-to-wafer bonding is provided. The bonding material stack may include a plurality of layers each including boron and nitrogen. In one embodiment, the plurality of layers may include: a first boron oxynitride layer for adhering to a wafer; a boron nitride layer over the first boron oxynitride layer; a second boron oxynitride layer over the boron nitride layer; and a silicon-containing boron oxynitride layer over the second boron oxynitride layer.