Method of improving read current stability in analog non-volatile memory by program adjustment for memory cells exhibiting random telegraph noise

A memory device comprising:

• a plurality of non-volatile memory cells each comprising a first gate;
• and
• a controller configured to program one non-volatile memory cell of the plurality of non-volatile memory cells by:
• programming the one non-volatile memory cell to an initial program state that corresponds to meeting or exceeding a target threshold voltage for the first gate of the one non-volatile memory cell, wherein the target threshold voltage corresponds to a target read current,
• reading the one non-volatile memory cell in a first read operation using a read voltage applied to the first gate of the one non-volatile memory cell that is less than the target threshold voltage to generate a first read current, and
• subjecting the one non-volatile memory cell to additional programming in response to determining that the first read current is greater than the target read current;
• wherein the controller is further configured to:
• read the one non-volatile memory cell in a second read operation, in response to determining that the first read current is not greater than the target read current in the first read operation, using a read voltage applied to the first gate of the one non-volatile memory cell that is less than the target threshold voltage to generate a second read current, and
• subject the one non-volatile memory cell to additional programming in response to determining that the second read current is greater than the target read current;
• wherein the controller is further configured to:
• apply a negative voltage to the first gate of the one non-volatile memory cell after the programming of the one non-volatile memory cell to the initial program state and before the first read operation;
• and
• apply a negative voltage to the first gate of the one non-volatile memory cell after the determining that the first read current is not greater than the target read current in the first read operation and before the second read operation.

A method of programming one non-volatile memory cell of a plurality of non-volatile memory cells, wherein each of the plurality of non-volatile memory cells includes a first gate, the method comprising:

• programming the one non-volatile memory cell to an initial program state that corresponds to meeting or exceeding a target threshold voltage for the first gate of the one non-volatile memory cell, wherein the target threshold voltage corresponds to a target read current,
• reading the one non-volatile memory cell in a first read operation using a read voltage applied to the first gate of the one non-volatile memory cell that is less than the target threshold voltage to generate a first read current, and
• subjecting the one non-volatile memory cell to additional programming in response to determining that the first read current is greater than the target read current;
• wherein the programming of the one non-volatile memory cell to the initial program state comprises:
• applying at least one first pulse of programming voltages to the one non-volatile memory cell;
• reading the one non-volatile memory cell using a read voltage applied to the first gate of the one non-volatile memory cell that is equal to the target threshold voltage to generate a second read current;
• and
• applying at least one second pulse of programming voltages to the one non-volatile memory cell in response to determining that the second read current is greater than the target read current.

A method of programming one non-volatile memory cell of a plurality of non-volatile memory cells, wherein each of the plurality of non-volatile memory cells includes a first gate, the method comprising:

• programming the one non-volatile memory cell to an initial program state that corresponds to meeting or exceeding a target threshold voltage for the first gate of the one non-volatile memory cell, wherein the target threshold voltage corresponds to a target read current,
• reading the one non-volatile memory cell in a first read operation using a read voltage applied to the first gate of the one non-volatile memory cell that is less than the target threshold voltage to generate a first read current,
• subjecting the one non-volatile memory cell to additional programming in response to determining that the first read current is greater than the target read current,
• reading the one non-volatile memory cell in a second read operation, in response to determining that the first read current is not greater than the target read current in the first read operation, using a read voltage applied to the first gate of the one non-volatile memory cell that is less than the target threshold voltage to generate a second read current,
• subjecting the one non-volatile memory cell to additional programming in response to determining that the second read current is greater than the target read current,
• applying a negative voltage to the first gate of the one non-volatile memory cell after the programming of the one non-volatile memory cell to the initial program state and before the first read operation, and
• applying a negative voltage to the first gate of the one non-volatile memory cell after the determining that the first read current is not greater than the target read current in the first read operation and before the second read operation.