Writing Memory Cells Exhibiting Threshold Switch Behavior
OwnerStephen Tanginventor
Life of this patent
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Abstract
A memory cell exhibiting threshold switch behavior, such as a phase change memory, can be programmed in a way that eliminates the need for a separate post-programming verification cycle. In particular, a circuit can be used to apply the programming pulse to a cell in a way that determines whether the cell has reached the desired threshold voltage. If the cell has not reached the desired threshold voltage, it receives another programming pulse. If it has, it does not receive another programming pulse. Thus, by applying a voltage across the cell that never exceeds the threshold voltage of the cell, the need for a separate verification cycle can be eliminated in some embodiments.
Claims25
A method comprising:
- programming a cell by applying, across the cell, a voltage that has a level less than or equal to a desired cell threshold voltage.
An apparatus comprising:
- a cell;
- and
- a circuit to selectively supply a programming current to the cell depending on whether or not the cell has reached a desired programming threshold voltage level.
An apparatus comprising:
- a phase change memory cell;
- and
- a circuit to determine whether the cell has reached a desired threshold current and, if not, to automatically supply additional programming current.
Dependencies are inferred from the claim text.