Globalfoundries Inc.

Rongtao Lu

Hui Zang

Haiting Wang

Guowei Xu

Ruilong Xie

Scott Beasor

Chih-Chiang Chang

Tao Chu

Ayse M Ozbek

Wei Ma

Disclosed is a metal gate (e.g., a replacement metal gate (RMG) for a field effect transistor (FET) and a method of forming the metal gate. The method includes depositing a conformal dielectric layer to line a gate opening and performing a series of unclustered and clustered conformal metal deposition and chamfer processes to selectively adjust the heights of conformal metal layers within the gate opening. By selectively controlling the heights of the conformal metal layers, the method provides improved overall gate height control and gate quality particularly when the metal gate has a small critical dimension (CD) and/or a high aspect ratio (AR). The method can also include using different etch techniques during the different chamfer processes and, particularly, when different materials and/or different material interfaces are exposed to an etchant in order to ensure an essentially uniform etch rate of the conformal metal layer(s) at issue in a direction that is essentially vertical.

Metal gate for a field effect transistor and method

The present disclosure relates to semiconductor structures and, more particularly, to chamfered replacement gate structures and methods of manufacture. The structure includes: a recessed gate dielectric material in a trench structure; a plurality of recessed workfunction materials within the trench structure on the recessed gate dielectric material; a plurality of additional workfunction materials within the trench structure and located above the recessed gate dielectric material and the plurality of recessed workfunction materials; a gate metal within the trench structure and over the plurality of additional workfunction materials, the gate metal and the plurality of additional workfunction materials having a planar surface below a top surface of the trench structure; and a capping material over the gate metal and the plurality of additional workfunction materials.

Chamfered replacement gate structures

A method includes forming a first cavity having a first width and a second cavity having a second width greater than the first width in a dielectric material, forming a first conformal layer in the first and second cavities, forming spacers in the first and second cavities, the spacers covering a first portion of the first conformal layer positioned on sidewalls of the first and second cavities and exposing a second portion of the first conformal layer positioned on the sidewalls of the first and second cavities, forming a material layer in the first and second cavities to cover bottom portions of the first conformal layer, performing a first etch process to remove the second portion of the first conformal layer positioned on the sidewalls of the first and second cavities, removing the spacers and the material layer, and forming a fill material in the first and second cavities.

Methods for chamfering work function material layers in gate cavities having varying widths

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Rexford, NY, United States of America

Rongtao Lu