Patent Number: 6,297,989

Title: Applications for non-volatile memory cells

Abstract: Additional applications for DRAM technology compatible non-volatile memorycells are presented. The novel applications include the integration ofDRAM technology compatible non-volatile memory cells which can befabricated on a DRAM chip with little or no modification of the DRAMoptimized process flow. The novel applications of DRAM technologycompatible non-volatile memory cells operate with lower programmingvoltages than that used by conventional non-volatile memory cells, yetstill hold sufficient charge to withstand the effects of parasiticcapacitances and noise due to circuit operation. Hence, the requirementsof low power densely packed integrated circuits is realized for smaller,portable microprocessor devices.An example of one such application includes a circuit switch. The circuitswitch has a non-volatile memory cell which a metal oxide semiconductorfield effect transistor (MOSFET) formed in a semiconductor substrate, acapacitor, and a vertical electrical via coupling a bottom plate of thecapacitor through an insulator layer to a gate of MOSFET. A wordline iscoupled to a top plate of the capacitor in the non-volatile memory cell. Asourceline is coupled to a source region of the MOSFET in the non-volatilememory cell. A bit line is coupled to a drain region of the MOSFET in thenon-volatile memory cell and coupled to a logic/select circuit.Another example of an application includes a shadow random access memory(RAM) cell. The shadow RAM cell has a non-volatile memory cell with thestructure described above. Circuit arrays and electronic systems whichincorporate these novel applications are included with the scope of thisinvention. Likewise, methods for forming and operating these novel deviceapplications are provided.

Inventors: Cloud; Eugene H. (Boise, ID), Noble; Wendell P. (Milton, VT)


International Classification:

Expiration Date: 10/02/2013