Patent attributes
One illustrative method disclosed herein includes, among other things, performing at least one recess etching process such that a first portion of a high-k oxide gate insulation layer and a first portion of a metal oxide layer is positioned entirely within a first gate cavity and a second portion of the high-k oxide gate insulation layer, a conformal patterned masking layer and a second portion of the metal oxide layer is positioned entirely within a second gate cavity, performing at least one heating process to form a composite metal-high-k oxide alloy gate insulation layer in the first gate cavity, while preventing metal from the metal oxide material from being driven into the second portion of the high-k oxide gate insulation layer in the second gate cavity during the at least one heating process, and forming gate electrode structures in the gate cavities.