Damascene word line

摘要

The technology relates to a damascene word line for a three dimensional array of nonvolatile memory cells. Partly oxidized lines of material such as silicon are made over a plurality of stacked nonvolatile memory structures. Word line trenches are made in the partly oxidized lines, by removing the unoxidized lines from the intermediate parts of the partly oxidized lines, leaving the plurality of oxidized lines at the outer parts of the plurality of partly oxidized lines. Word lines are made in the word line trenches over the plurality of stacked nonvolatile memory structures.

主权项

1. A method of making a three dimensional array of nonvolatile memory cells, comprising:
making a first plurality of material lines over a plurality of stacked nonvolatile memory structures, the first plurality of material lines separated by a first plurality of word line trenches that separate neighboring ones of the first plurality of material lines; making a plurality of partly oxidized structures from the first plurality of material lines by oxidizing both sides of material lines in the first plurality of material lines, the plurality of partly oxidized structures including a plurality of oxide lines bounding a first plurality of narrowed material lines, wherein narrowed material lines in the first plurality of narrowed material lines have a narrower width than the material lines in the first plurality of material lines; removing the first plurality of narrowed material lines bounded by the plurality of oxide lines, to make a second plurality of word line trenches; and making a plurality of word lines over the plurality of stacked nonvolatile memory structures in the first plurality of word line trenches and the second plurality of word line trenches.