A flat-aluminum based voltage-programmable link for field-programmable devices

A new metal-insulator-metal (MIM) structure has been developed for use in field-programmable gate arrays (FPGA´s) as a voltage-programmable link (VPL). The present capacitor structure relies on aluminum metallization; hence, it should be amenable to immediate application. The addition of minute amounts of titanium or molybdenum has been found to suppress hillock formation. The insulator, prepared by means of plasma-enhanced chemical vapor deposition (PECVD), comprises a sandwich of a nearly stoichiometric silicon dioxide interposed between two like layers of silicon-rich silicon nitride. This MIM structure has displayed characteristics desirable for use in the emerging FPGA technology including high density, very low on-resistance, reduced capacitance, low programming voltage, and the potential for further scaling to the sub-micron regime