US 2017/0256320 A1 · Adaptive Determination Of Program Parameter Using Program Of Erase Rate

Abstract

Techniques are provided for optimizing the programming of memory cells by obtaining a metric which indicates a program or erase rate of the memory cells. In one approach, a count of pulses used to program the cells to different verify levels of respective data states is stored. A slope of a straight line fit of data points is then obtained. Each data point can include one of the verify levels and a corresponding one of the counts. An optimal step size is determined based on the slope. The counts may exclude one or more initial program voltages while the cells are programmed sufficiently to allow faster and slower cells to be distinguished, e.g., in a natural threshold voltage distribution. An erase depth can also be adjusted. The cells can be programmed in a separate evaluation or during programming of user data.

Claims20

Dependent claims

An apparatus, comprising:

a set of memory cells in a block;
sense circuits connected to the set of memory cells;
a driver connected to the set of memory cells;
and
a control circuit, the control circuit configured to:
cause the driver to apply a set of pulses to the set of memory cells,
cause the sense circuits to evaluate a characteristic of the set of memory cells, the characteristic comprises threshold voltage, current or resistance;
based on results from the sense circuits, determine a rate of change of the characteristic,
set an adjustable programming parameter based on the rate of change of the characteristic, and
program memory cells in the block using the adjustable programming parameter.

7 more elements

Dependencies are inferred from the claim text.

Adaptive Determination Of Program Parameter Using Program Of Erase Rate

Life of this patent

Adaptive Determination Of Program Parameter Using Program Of Erase Rate

Life of this patent

Abstract

Claims20