Si on Si3N4 bonded wafers are the substrates used in semiconductor manufacturing that consists of a layer of silicon (Si) bonded to a layer of silicon nitride (Si3N4). This type of wafer is used in a variety of applications, including the manufacture of MEMS (micro-electromechanical systems), optoelectronic devices, and integrated circuits.
The silicon nitride layer provides a number of benefits, including improved thermal stability, reduced stress, and reduced parasitic capacitance. The Si layer provides a high-quality substrate for the growth of other materials and structures, such as epitaxial layers.
Si on Si3N4 bonded wafers are typically fabricated using a process called direct bonding, in which the Si and Si3N4 surfaces are brought into contact under controlled conditions and bonded together. After bonding, the Si substrate can be thinned to the desired thickness using techniques such as chemical mechanical polishing (CMP) or grinding.