Laser programmable electrically readable phase-change memory method and device
AssigneeMacronix International Co., Ltd.
InventorsChih-Yuan Lu, Yi-Chou Chen
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Abstract
Roughly described, a phase-change memory such as a chalcogenide-based memory is programmed optically and read electrically. No complex electrical circuits are required for programming the cells. On the other hand, this memory can be read by electrical circuitry directly. The read out speed is much faster than for optical disks, and integrated circuit chips made this way are more compatible with other electrical circuits than are optical disks. Thus memories according to the invention can have simple, low power-consuming, electrical circuits, and do not require slow and power-hungry disk drives for reading. The invention therefore provides a unique low power, fast read/write memory with simple electrical circuits.
Claims27
A method of operating a plurality of memory cells each including a respective region of phase change material having at least two electrically-distinguishable states, the two states for each of said regions having respective solid phases, said plurality of memory cells including a first memory cell that includes a first region of said phase change material, comprising the steps of:
- repeatedly scanning a laser spot across regions of said phase change material, said laser spot programming said first region of phase change material on respective different scans to be in different ones of said states;
- and
- reading the state of said first memory cell electronically.
A memory device for use with a laser source for producing a laser spot, comprising:
- a support structure having a surface for receiving said laser spot, the support structure being rotatable relative to said laser spot;
- and
- an integrated circuit chip disposed on said surface so as to be scanned by said laser spot as said support structure rotates.
Dependencies are inferred from the claim text.