System and method for programming cells in non-volatile integrated memory devices
AssigneeSanDisk Corporation
InventorsNima Mokhlesi, John H. Pasternak
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Abstract
A system and method for quickly and efficiently programming hard-to-program storage elements in non-volatile integrated memory devices is presented. A number of storage elements are simultaneously subjected to a programming process with the current flowing through the storage elements limited to a first level. As a portion of these storage elements reach a prescribed state, they are removed from the set of cells being programmed and the current limit on the elements that continue to be programmed is raised. The current level in these hard-to-program cells can be raised to a second, higher limit or unregulated.
Claims23
A method of programming a non-volatile memory array comprising:
- simultaneously applying a first set of programming voltage waveforms to the terminals of a plurality of memory storage units, wherein the current flowing between a first and a second of the terminals of each of the plurality of storage units is limited to be not greater than a first current level;
- and
- subsequent to said applying a first set of programming voltage waveforms, simultaneously applying a second set of programming voltage waveforms to the terminals of a first subset of the plurality memory storage units, wherein the current flowing between the first and the second of the terminals of each of the first subset is not limited to be not greater than the first current level.
A non-volatile memory comprising:
- a plurality of memory storage units;
- a current limiting circuit connectable to the memory storage units whereby the amount of a current flowing through a connected storage unit can be controlled;
- and
- programming cicuitry connected to the storage units and the current limiting circuit, whereby during an operation simultaneously programming one or more of said plurality of storage units, the respective current flowing in each of said one or more storage units can be limited to be not greater than a first current level in a first mode and allowed to exceed the first current level in a second mode.
Dependencies are inferred from the claim text.