Dual metal fill and dual threshold voltage for replacement gate metal devices
AssigneeInternational Business Machines Corporation
InventorsLisa F. Edge, Nathaniel Berliner, James John Demarest, Balasubramanian S. Haran, Raymond J. Donohue
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Abstract
A structure and method for forming a dual metal fill and dual threshold voltage for replacement gate metal devices is disclosed. A selective deposition process involving titanium and aluminum is used to allow formation of two adjacent transistors with different fill metals and different workfunction metals, enabling different threshold voltages in the adjacent transistors.
Claims13
A method for forming two transistors having different threshold voltages comprising:
- forming a first gate cavity in a first transistor and a second gate cavity in a second transistor;
- depositing a gate dielectric film in the first gate cavity and the second gate cavity;
- depositing a first workfunction metal in the first gate cavity and the second gate cavity;
- depositing a titanium layer in the first gate cavity and the second gate cavity;
- removing the titanium layer from the second gate cavity, thereby leaving a remaining portion of the titanium layer disposed in the first gate cavity;
- depositing a first fill metal of aluminum on the remaining portion of the titanium layer via a selective deposition process without depositing a mask on the second gate cavity, wherein the first fill metal of aluminum is not deposited above the second gate cavity;
- depositing a second workfunction metal in the second gate cavity;
- depositing a second fill metal in the second gate cavity;
- and
- planarizing the first and second transistors.
A method for forming two transistors having different threshold voltages comprising:
- forming a first gate cavity in a first transistor and a second gate cavity in a second transistor;
- depositing a gate dielectric film in the first gate cavity and the second gate cavity;
- depositing a first workfunction metal in the first gate cavity and the second gate cavity;
- depositing a titanium layer in the first gate cavity and the second gate cavity;
- depositing a hardmask layer in the first gate cavity and the second gate cavity;
- removing a portion of the hardmask layer from the second gate cavity;
- removing the titanium layer from the second gate cavity, thereby leaving a remaining portion of the titanium layer disposed in the first gate cavity;
- removing the hardmask layer from the first gate cavity;
- depositing a first fill metal comprised of aluminum on the remaining portion of the titanium layer via a selective deposition process without depositing a mask on the second gate cavity, wherein the first fill metal of aluminum is not deposited above the second gate cavity;
- depositing a second workfunction metal in the second gate cavity;
- depositing a second fill metal in the second gate cavity;
- and
- planarizing the first and second transistors.
Dependencies are inferred from the claim text.