Patent ID: 9666449
Date: 2017-05-30
CPC Classifications: H01L

Claim:
1. A method of forming a control gate, comprising: forming a conductor over a first dielectric by varying a flow rate of reactants that form germanium according to a predetermined function of time or of a number of pulse/purge cycles to form the conductor comprising a concentration of germanium that varies as a predetermined function of a thickness of the conductor; forming a second dielectric over the conductor so that the conductor is between the first dielectric and the second dielectric; forming an opening that extends through the second dielectric, the conductor, and the first dielectric; and recessing an end of the conductor adjacent to the opening relative to ends of the first and second dielectrics adjacent to the opening by removing portions of the conductor at a variable rate that is governed, at least in part, by the concentration of the germanium so that a distance from the end of the conductor to the ends of the first and second dielectrics varies with the thickness of the conductor, wherein a largest distance from the end of the conductor to the ends of the first and second dielectrics occurs at a thickness of the conductor that is at a center of the conductor midway between the first and second dielectrics.