METHOD FOR MANUFACTURING A DOUBLE-GATE ELECTRONIC MEMORY CELL AND ASSOCIATED MEMORY CELL

摘要

A method of manufacturing a double-gate electronic memory cell is presented. The cell includes a substrate; a first gate structure, with the first gate structure having a lateral flank; a stack including several layers and of which a layer is able to store electrical charges, the stack covering the lateral flank of the first gate structure and a portion of the substrate; and a second gate structure. The second gate structure includes a first portion formed from a first gate material; a second portion formed from a second gate material, with the first gate material able to be etched selectively in relation to the second gate material and with the second gate material able to be etched selectively in relation to the first gate material; a first zone of silicidation extending over the first portion of the second gate structure; and a second zone of silicidation extending over the second portion of the second gate structure.

主权项

1. A method for manufacturing an electronic memory cell comprising:
a substrate; a first gate structure deposited on the substrate; a stack comprising a plurality of layers and of which at least one of said layers is able to store electrical charges, said stack covering at least a lateral flank of the first gate structure and a portion of the substrate; a second gate structure insulated from the first gate structure and from the substrate by the stack; said method comprising forming the second gate structure by:
depositing a layer of a first material of the second gate structure at least on a zone covered by the stack;depositing a layer of a second material of the second gate structure at least on a zone covered by the layer of the first material, said second material able to be etched selectively in relation to said first material and said first material able to be etched selectively in relation to said second material;etching the thickness of the layer of second material selectively in relation to the first material in such a way as to retain a portion of the second material laterally covering the first material;etching the thickness of the layer of the first material selectively in relation to the second material in such a way as to retain the portion of the first material laterally covering the stack, with the second gate structure comprising as such said portion of the first material laterally covering the stack and at least one portion of said portion of the second material laterally covering the first material;performing a silicidation of a first zone extending over said first region of the second gate structure, and of a second zone extending over said second region of the second gate structure.