Methods of forming integrated circuitry comprising charge storage transistors

Abstract

Methods include forming a charge storage transistor gate stack over semiconductive material. One such stack includes a tunnel dielectric, charge storage material over the tunnel dielectric, a high-k dielectric over the charge storage material, and conductive control gate material over the high-k dielectric. The stack is etched at least to the tunnel dielectric to form a plurality of charge storage transistor gate lines over the semiconductive material. Individual of the gate lines have laterally projecting feet which include the high-k dielectric. After etching the stack to form the gate lines, ions are implanted into an implant region which includes the high-k dielectric of the laterally projecting feet. The ions are chemically inert to the high-k dielectric. The ion implanted high-k dielectric of the projecting feet is etched selectively relative to portions of the high-k dielectric outside of the implant region.