International Business Machines Corporation
Gate metal patterning to avoid gate stack attack due to excessive wet etching

Abstract:

A method of forming gate structures to a nanosheet device that includes forming at least two stacks of nanosheets, wherein each nanosheet includes a channel region portion having a gate dielectric layer present thereon. The method may further include forming a dual metal layer scheme on the gate dielectric layer of each nanosheet. The dual metal layer scheme including an etch stop layer of a first composition and a work function adjusting layer of a second composition, wherein the etch stop layer has a composition that provides that the work function adjusting layer is removable by a wet etch chemistry that is selective to the etch stop layer.