A memory circuit includes a first driver circuit, a memory cell array including a first column of memory cells, a first transistor coupled between the first driver circuit and the memory cell array, a second driver circuit, a first column of tracking cells and a header circuit coupled to the first driver circuit and the second driver circuit. The first transistor is configured to receive a first select signal. The first column of tracking cells is configured to track a leakage current of the first column of memory cells, and is coupled between a first conductive line and a second conductive line, the first conductive line being coupled to the second driver circuit.

A memory device includes a page buffer, a voltage generator, and a test controller. The page buffer is connected to a memory cell through a bit line, and is configured to sense a threshold voltage of the memory cell through a potential of a sensing node electrically connected to the bit line. The voltage generator is configured to generate a test voltage to be applied to the sensing node. The test controller is configured to control the voltage generator to apply the test voltage to the sensing node, and detect a defect of the page buffer, based on a leakage current value of the sensing node.

A memory device includes a memory array with memory blocks each having a plurality of memory cells, and one or more current monitors configured to measure current during post-deployment operation of the memory device; and a controller configured to identify a bad block within the memory blocks based on the measured current, and disable the bad block for preventing access thereof during subsequent operations of the memory device.

Methods, systems, and devices for leakage source detection are described. In some cases, a testing device may scan a first set of access lines of a memory die that have a first length and a second set of access lines of the memory die that have a second length different than the first length. The testing device may determine a first error rate associated with the first set of access lines and a second error rate associated with the second set of access lines. The testing device may categorize a performance of the memory die based on the first and second error rates. In some cases, the testing device may determine a third error rate associated with a type of error based on the first and second error rates and may categorize the performance of the memory die based on the third error rate.

The present invention discloses a multi-bit-per-cell three-dimensional resistive random-access memory (3D-RRAM.sub.MB). It comprises a plurality of RRAM cells stacked above a semiconductor substrate. Each RRAM cell comprises a RRAM layer, which is switched from a high-resistance state to a low-resistance state during programming. By adjusting the programming current, the programmed RRAMs have different resistances.

In one example, a method is disclosed of compensating for leakage in an array of analog neural non-volatile memory cells, wherein the array is arranged in rows and columns, wherein each row is coupled to a word line and each column is coupled to a bitline, the method comprising measuring leakage for a column of analog neural non-volatile memory cells coupled to a bitline; storing the measured leakage value; and applying the measured leakage value during a read operation of the column of analog neural non-volatile memory cells to compensate for the leakage.

A leakage detection circuit may include: a comparison circuit configured to compare an input voltage, which changes based on the level of an operation voltage node, to a reference voltage and configured to output a detection signal; and a state decision circuit configured to determine a count value that corresponds to a determination period based on the detection signal and configured to output leakage state information based on the count value.

A variety of applications can include devices or methods that provide read processing of data in memory cells of a memory device without predetermined read levels for the memory cells identified. A read process is provided to vary a selected access line gate voltage over time, creating a time-variate sequence where memory cell turn-on correlates with programmed threshold voltage. Total string current of data lines of a group of strings of memory cells of the memory device can be monitored during a read operation of selected memory cells of the strings to which a ramp voltage with positive slope is applied to an access line coupled to the selected memory cells. Selected values of the change of the total current with respect to time, from the monitoring of the total current, are determined. Read points to capture data are based on the determined selected values. Additional devices, systems, and methods are discussed.

A method for screening memory cells includes erasing the memory cells, weakly programming the memory cells to a modified erased state, performing a first read operation on the memory cells after the erasing and the weakly programming, screening any of the memory cells that exhibit a read current during the first read operation below a margin read current threshold M1, baking the memory cells after the first read operation, performing a second read operation on the memory cells after the baking, and screening any of the memory cells that exhibit a read current during the second read operation below the margin read current threshold M1.

A memory device includes a page buffer, a voltage generator, and a test controller. The page buffer is connected to a memory cell through a bit line, and is configured to sense a threshold voltage of the memory cell through a potential of a sensing node electrically connected to the bit line. The voltage generator is configured to generate a test voltage to be applied to the sensing node. The test controller is configured to control the voltage generator to apply the test voltage to the sensing node, and detect a defect of the page buffer, based on a leakage current value of the sensing node.