METHOD FOR FORMING PCM AND RRAM 3-D MEMORY CELLS

摘要

A method for fabricating 3-D cross-point memory arrays, and more particularly to fabricating phase change memory (PCM) and resistive RAM (ReRAM or RRAM) 3-D memory arrays having a cell size footprint of 4F2. The method for forming a plurality of layers of memory cells using a limited number of photolithographic patterning steps is applicable to memory devices having single or multiple storage bits per cell, such as cells having anywhere from one to eight bits per cell or more. These bits are stacked three dimensionally and include memory cells based on phase change material, on resistive change material, on magnetic field alignment, on mechanical switching, and on other memory cells based on other information storage technologies.

主权项

1. A method of fabricating memory cells, comprising:
depositing onto a substrate a first layer stack, wherein the substrate includes a plurality of selector contacts and wherein the selector contacts have an upper surface; patterning and etching the first layer stack to form a plurality of word lines and to form a plurality of trenches; depositing a first insulating layer within the plurality of trenches; etching a first insulating layer; depositing a metal within the plurality of trenches; patterning and etching the metal to form a vertical post and to form a plurality of holes, wherein the vertical posts are disposed on the upper surface of the selector contacts; depositing a second insulating layer within the plurality of holes; etching the second insulating layer, wherein the etching is biased towards a side of each of the plurality of holes; and depositing a conductive material into the plurality of holes.