Cross-point self-aligned reduced cell size phase change memory

Abstract

A programmable memory array is disclosed in which the phase change memory cells are self-aligned at the access devices and at the cross-points of the bit lines and the word lines. A method for making the array employs one line mask to define the bit lines and another line mask to define the word lines. The front end of line (FEOL) memory cell elements are in the same layer as the polysilicon gates. The bit lines and the word lines intersect over the devices, and the memory cell elements are formed at the intersections of the bit lines and the word line.

Description

technical field [0001] The present invention relates to high-density programmable memory devices based on phase-change memory materials, including chalcogen-based materials, and other programmable resistive materials. Background technique [0002] Phase-change based memory materials, such as chalcogen-based materials and the like, can change between an amorphous state and a crystalline state due to the application of a potential current suitable for implementation in integrated circuits. Commonly amorphous states are characterized by higher resistance than common crystalline states, which can be easily sensed to indicate data. These qualities have sparked interest in the use of programmable impedance materials to form non-volatile memory circuits that can be accessed with random access. read and write. [0003] The change from the amorphous state to the crystalline state is generally a lower current operation, and the change from the amorphous state to the crystalline state...

AI Technical Summary

Problems solved by technology

[0004] While increasing the density of memory cells within a memory cell array is desirable, proper alignment of memory cells with corresponding access devices as well as word and bit lines presents challenges as feature sizes shrink

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