NAND STRING CONTAINING SELF-ALIGNED CONTROL GATE SIDEWALL CLADDING

摘要

A method of making a NAND string includes forming a tunnel dielectric over a semiconductor channel, forming a charge storage layer over the tunnel dielectric, forming a blocking dielectric over the charge storage layer, and forming a control gate layer over the blocking dielectric. The method also includes patterning the control gate layer to form a plurality of control gates separated by trenches, and reacting a first material with exposed sidewalls of the plurality of control gates to form self aligned metal-first material compound sidewall spacers on the exposed sidewalls of the plurality of control gates.

主权项

1. A NAND string, comprising:
a semiconductor channel; a tunnel dielectric located over a semiconductor channel; a plurality of floating gates separated by trenches located over the tunnel dielectric; a plurality of blocking dielectric regions separated by the trenches, each of the plurality of blocking dielectric regions is located over at least a respective one of the plurality of floating gates; a plurality of control gates separated by the trenches, each of the plurality of control gates is located over a respective one of the plurality of blocking dielectric regions; and a plurality of metal-first material compound sidewall spacers located on sidewalls of the plurality of control gates; wherein the sidewall spacers protrude into the trenches beyond sidewalls of respective floating gates located under the control gates.