A method of improving stability of a memory device having a controller configured to program each of a plurality of non-volatile memory cells within a range of programming states bounded by a minimum program state and a maximum program state. The method includes testing the memory cells to confirm the memory cells are operational, programming each of the memory cells to a mid-program state, and baking the memory device at a high temperature while the memory cells are programmed to the mid-program state. Each memory cell has a first threshold voltage when programmed in the minimum program state, a second threshold voltage when programmed in the maximum program state, and a third threshold voltage when programmed in the mid-program state. The third threshold voltage is substantially at a mid-point between the first and second threshold voltages, and corresponds to a substantially logarithmic mid-point of read currents.

A memory device that includes a plurality of non-volatile memory cells and a controller. The controller is configured to erase the plurality of memory cells, program each of the memory cells, and for each of the memory cells, measure a threshold voltage applied to the memory cell corresponding to a target current through the memory cell in a first read operation, re-measure a threshold voltage applied to the memory cell corresponding to the target current through the memory cell in a second read operation, and identify the memory cell as defective if a difference between the measured threshold voltage and the re-measured threshold voltage exceeds a predetermined amount.

Memory devices might include a controller configured to cause the memory device to apply a first plurality of incrementally increasing programming pulses to control gates of a particular plurality of memory cells selected for programming to respective intended data states, determine a first occurrence of a criterion being met, store a representation of a voltage level corresponding to a particular programming pulse in response to the first occurrence of the criterion being met, set a starting programming voltage for a second plurality of incrementally increasing programming pulses in response to the stored representation of the voltage level corresponding to the particular programming pulse, and apply the second plurality of incrementally increasing programming pulses to control gates of a different plurality of memory cells selected for programming to respective intended data states.

An operating method of a non-volatile memory device including a plurality of memory cells respectively connected to a plurality of word lines is provided. The operating method includes applying an erase detect voltage to a selected word line of the plurality of word lines to perform an erase detect operation on memory cells connected to the selected word line in response to a program command, applying a program voltage to the selected word line after the erase detect operation, and counting a number of undererased cells of the memory cells on which the erase detect operation has been performed.

A methodology and structure for driving a selected wordline to a negative voltage without the need for a negative wordline voltage generator. The methodology includes the step of boosting a non-selected wordline to a first positive voltage. The methodology proceeds with holding a selected wordline, which is adjacent to and capacitively coupled with the non-selected wordline, at zero voltage. The methodology continues with floating the selected wordline. The methodology proceeds with driving the non-selected wordline to a lower voltage to shift the selected wordline to less than zero volts due to capacitance effects. The methodology continues with the step of accelerating charge loss in a defective memory cell connected to the selected wordline while at a negative voltage during a soft erase operation.

Methods of operating a memory device include programming a page of a memory block of the memory device using a particular starting programming voltage, determining a programming voltage indicative of a programming efficiency of the page of the memory block during programming of the page of the memory block, storing a representation of the programming voltage indicative of the programming efficiency of the page of the memory block, setting a starting programming voltage for a different page of the memory block in response to the stored representation of the programming voltage indicative of the programming efficiency of the page of the memory block, and programming the different page of the memory block using its starting programming voltage.

An operating method of a non-volatile memory device including a plurality of memory cells respectively connected to a plurality of word lines is provided. The operating method includes applying an erase detect voltage to a selected word line of the plurality of word lines to perform an erase detect operation on memory cells connected to the selected word line in response to a program command, applying a program voltage to the selected word line after the erase detect operation, and counting a number of undererased cells of the memory cells on which the erase detect operation has been performed.

An operating method of a non-volatile memory device including a plurality of memory cells respectively connected to a plurality of word lines is provided. The operating method includes applying an erase detect voltage to a selected word line of the plurality of word lines to perform an erase detect operation on memory cells connected to the selected word line in response to a program command, applying a program voltage to the selected word line after the erase detect operation, and counting a number of undererased cells of the memory cells on which the erase detect operation has been performed.

The present embodiments relate to methods for estimating bit error rates (BERs) associated with a flash memory. According to certain aspects, embodiments provide estimating the BER of multi-bit flash memories during the programming of the flash memory, and providing the estimated BER in a readable status register of the flash memory, thereby improving the speed of programming of the flash memory.

A first data stored at a first portion of a memory cell and a second data stored at a second portion of the memory cell are identified. A first error rate associated with first data stored at the first portion of the memory cell is determined. The first error rate is adjusted to exceed a second error rate associated with the second data stored at the second portion of the memory cell. A determination is made as to whether the first error rate exceeds a threshold. The second data stored at the second portion of the memory cell is provided for use in an error correction operation by a controller associated with the memory cell in response to determining that the first error rate exceeds the threshold.