Patent Number: 7,826,288

Title: Device threshold calibration through state dependent burn-in

Abstract: In a method for reducing and/or eliminating mismatch in one or more devices that require a balanced state (e.g., in cross-coupled transistors in each memory cell and/or sense amp in a memory array), the bias (i.e., the preferred state) of each of the devices is determined. Then, a burn-in process is initiated, during which an individually selected state is applied to each of the devices. This fatigues the devices away from their preferred states and towards a balanced state. The bias is periodically reassessed during the burn-in process to avoid over-correction. By using this method both memory cell and sense-amplifier mismatch can be reduced in memory arrays, resulting in smaller timing uncertainty and therefore faster memories.

Inventors: Arsovski; Igor (Williston, VT), Pilo; Harold (Underhill, VT), Ziegerhofer; Michael A. (Jeffersonville, VT)

Assignee: International Business Machines Corporation

International Classification: G11C 29/00 (20060101); G11C 29/50 (20060101); G11C 11/413 (20060101); G11C 7/06 (20060101); G11C 29/06 (20060101); G11C 11/412 (20060101)

Expiration Date: 2019-11-02 0:00:00