Embodiments of this application provide a method and system for adjusting a memory, and a semiconductor device. The method for adjusting a memory includes: acquiring a mapping relationship among a temperature of a transistor, a substrate bias voltage of a sense amplification transistor in a sense amplifier, and an actual data writing time of the memory; acquiring a current temperature of the transistor; and adjusting the substrate bias voltage on the basis of the current temperature and the mapping relationship, such that an actual data writing time corresponding to an adjusted substrate bias voltage is within a preset writing time.

Memory devices and methods of operating memory devices in which maintenance operations can be scheduled on an as-needed basis for those memory portions where activity (e.g., operations in excess of a predetermined threshold) warrants a maintenance operation are disclosed. In one embodiment, an apparatus comprises a memory including a memory location, and circuitry configured to determine a count corresponding to a number of operations at the memory location, to schedule a maintenance operation for the memory location in response to the count exceeding a first predetermined threshold, and to decrease the count by an amount corresponding to the first predetermined threshold in response to executing the scheduled maintenance operation. The circuitry may be further configured to disallow, in response to determining that the count has reached a maximum permitted value, further operations at the memory location until after the count has been decreased.

Methods, systems, and devices are described for operating a memory array. A first voltage may be applied to a memory cell to activate a selection component of the memory cell prior to applying a second voltage to the memory cell. The second voltage may be applied to facilitate a sensing operation once the selection component is activated. The first voltage may be applied during a first portion of an access operation and may be used in determining a threshold voltage of the selection component. The subsequently applied second voltage may be applied during a second portion of the access operation and may have a magnitude associated with a preferred voltage for accessing a ferroelectric capacitor of the memory cell. In some cases, the second voltage has a greater rate of increase over time (e.g., a greater ramp) than the first voltage.

Methods, systems, and devices for recovering fatigued ferroelectric memory cells are described. Recovery voltages may be applied to a ferroelectric memory cell that is fatigued due to repeated access (read or write) operations. The recovery voltage may have a greater amplitude than the access voltage and may include multiple voltage pulses or a constant voltage. The recovery operation may be performed in the background as the memory array operates, or it may be performed when a host device is not actively using the memory array. The recovery operations may be performed periodically or may include discrete series of pulses distributed among several instances.

Methods, systems, and devices are described for operating a memory array. A first voltage may be applied to a memory cell to activate a selection component of the memory cell prior to applying a second voltage to the memory cell. The second voltage may be applied to facilitate a sensing operation once the selection component is activated. The first voltage may be applied during a first portion of an access operation and may be used in determining a threshold voltage of the selection component. The subsequently applied second voltage may be applied during a second portion of the access operation and may have a magnitude associated with a preferred voltage for accessing a ferroelectric capacitor of the memory cell. In some cases, the second voltage has a greater rate of increase over time (e.g., a greater ramp) than the first voltage.

Methods, systems, and devices for recovering fatigued ferroelectric memory cells are described. Recovery voltages may be applied to a ferroelectric memory cell that is fatigued due to repeated access (read or write) operations. The recovery voltage may have a greater amplitude than the access voltage and may include multiple voltage pulses or a constant voltage. The recovery operation may be performed in the background as the memory array operates, or it may be performed when a host device is not actively using the memory array. The recovery operations may be performed periodically or may include discrete series of pulses distributed among several instances.

According to one embodiment, a semiconductor storage device includes: a first select transistor connected at a first end of a memory string; a second select transistor connected at a second end of the memory string; and a controller. In a write operation of writing data into a first memory cell transistor of the memory string, the controller performs: a first operation of applying a first voltage to a gate of the first memory cell transistor, while turning on the first and second select transistor;

and a second operation of applying a second voltage higher than the first voltage to the gate of the first memory cell transistor, while turning off the first and second select transistor; and the second operation is performed after the first operation.

Memory devices and methods of operating memory devices in which maintenance operations can be scheduled on an as-needed basis for those memory portions where activity (e.g., operations in excess of a predetermined threshold) warrants a maintenance operation are disclosed. In one embodiment, an apparatus comprises a memory including a memory location, and circuitry configured to determine a count corresponding to a number of operations at the memory location, to schedule a maintenance operation for the memory location in response to the count exceeding a first predetermined threshold, and to decrease the count by an amount corresponding to the first predetermined threshold in response to executing the scheduled maintenance operation. The circuitry may be further configured to disallow, in response to determining that the count has reached a maximum permitted value, further operations at the memory location until after the count has been decreased.

Methods, systems, and devices for recovering fatigued ferroelectric memory cells are described. Recovery voltages may be applied to a ferroelectric memory cell that is fatigued due to repeated access (read or write) operations. The recovery voltage may have a greater amplitude than the access voltage and may include multiple voltage pulses or a constant voltage. The recovery operation may be performed in the background as the memory array operates, or it may be performed when a host device is not actively using the memory array. The recovery operations may be performed periodically or may include discrete series of pulses distributed among several instances.

A method for programming a memory cell to a predetermined programmed state includesL (a) preparing the memory cell for a write operation; (b) sending a train of programming pulses, each programming pulse being a pulse having a magnitude sufficient to program the memory cell to the predetermined programmed state; (c) preparing the memory cell for a read operation; and (d) reading the programmed state of the memory cell to ascertain whether or not the predetermined programmed state is in the memory cell. In one embodiment, the method repeats steps (a)-(d), when the programmed state of the memory cell is not the predetermined programmed state. In one embodiment, the number of times steps (a)-(d) is repeated is determined based on both a probability of successfully writing the memory cell using a single write pulse and a probability of chaotic switching.