Texas Instruments Corporation

Clyde F Dunn

Stephen Keith Heinrich-Barna

Aswin N Mehta

John Howard MacPeak

Andrew M Love

Robert M Crosby

John H Macpeak

Mohammed A Hassan

A disturb management technique for a non-volatile memory including first and second memory cells includes programming the first memory cell by applying a first voltage to a first word line coupled to the first memory cell and a second voltage to a terminal, such as a source terminal, shared by the first memory cell and the second memory cell. A non-zero third voltage having the same sign as the second voltage is applied to a second word line coupled to the second memory cell. The applied non-zero third voltage reduces a tunnel current across a gate oxide that insulates the second word line from a substrate of the second memory cell. This results in the second memory cell having a lower likelihood of being disturbed when programming the first memory cell.

Method for suppressing gate oxide tunnel current in non-volatile memory to reduce disturbs

In a Flash memory unit, the storage of a logic signal in the memory cells is determined by performing a READ operation. The NORMAL READ operation requires that the floating gate store an amount of charge Q above which a logic &ldquo;0&rdquo; is identified and below which a logic &ldquo;1&rdquo; is identified as being stored in the memory cell. A second level of charge Q stored on the floating gate is used in a TEST READ operation. The stored charge Q is greater than the stored charge Q , but less than the charge stored on the floating gate as the result of a WRITE operation. The result of a TEST READ operation is compared with a NORMAL READ operation of a memory cell. When the logic state identified by the TEST READ operation and the NORMAL READ operation are not the same, the charge on the cell is determined to have decayed below a prescribed level and the memory cell is refreshed to the level that is present during a WRITE operation.

Apparatus and method for refreshing a flash memory unit

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Sugar Land, TX, United States of America

Clyde F Dunn