A NOVEL METAL-INSULATOR METAL STRUCTURE FOR FIELD-PROGRAMMABLE DEVICES

A novel metal-insulator-metal (MIM) capacitor structure has been devel oped for use in field-programmable gate arrays (FPGA's) as a voltage-p rogrammable link (VPL). The new structure relies on a combination of a refractory metal and aluminum as the lower electrode, and either a si milar combination or aluminum alone as the top electrode. The insulato r is prepared by means of plasma-enhanced chemical vapor deposition (P ECVD); it comprises a sandwich of nearly stoichiometric silicon dioxid e interposed between two like layers of silicon-rich silicon nitride. The present structure has displayed characteristics desirable for use in the emerging FPGA technology including high density, low on-resista nce, reduced capacitance, and low programming voltage.