Materials and Process for Compatible Construction of Surface Acoustic Wave Devices to Be Integrated With MOS Circuitry
Original Publication Date: 1985-Apr-01
Included in the Prior Art Database: 2005-Feb-18
This process and set of resulting film layers provides 1) thermal stability at MOS fabrication temperatures, 2) the electric field shield necessary between an overlying surface acoustic wave (SAW) device and a silicon substrate, while providing 3) a surface over the conductor allowing formation of a high quality piezoelectric film for the SAW device. The figures portray the layers resulting from the process. A refractory metal silicide (e.g., WSi or TiSi) is used as the conductive field shield between the piezoelectric film, e.g., ZnO, and the single crystal, silicon substrate. A nonstoichiometric (high Si) top layer is formed during the final stages of a Low Pressure Chemical Vapor Deposition (LPCVD) of WSi.