Work function adjustment with the implant of lanthanides
AssigneeTexas Instruments Incorporated
InventorsManfred Ramin, Michael F. Pas, Husam Alshareef
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Abstract
Semiconductor devices and fabrication methods are provided, in which fully silicided gates are provided. A lanthanide series metal is implanted into the gate electrode layer prior to silicidation and diffuses into the gate dielectric during an activation anneal. This process and resultant structure provides adjustment of the gate electrode work function, thereby tuning the threshold voltage of the resulting transistor.
Claims14
A method of forming a semiconductor device, comprising:
- forming a gate dielectric over a semiconductor body;
- forming a gate electrode over the gate dielectric;
- introducing a lanthanide series material into the gate electrode;
- and
- driving the lanthanide series material into the gate dielectric.
A method of forming a transistor, comprising:
- forming a gate dielectric over a semiconductor body, wherein the gate dielectric comprises a lanthanide series material in a top portion thereof;
- and
- forming a silicon gate electrode over the gate dielectric;
- wherein forming the gate dielectric comprises:
- forming a silicon oxide interface layer on the semiconductor body;
- forming a dielectric layer on the silicon oxide interface layer;
- and
- diffusing the lanthanide series material into the dielectric material from an overlying source of the lanthanide series material.
A method of forming a transistor, comprising:
- forming a gate dielectric over a semiconductor body;
- forming a silicon gate electrode over the gate dielectric;
- implanting a lanthanide series dopant into the silicon gate electrode;
- and
- performing an activation anneal, thereby causing lanthanide series material to diffuse into the gate dielectric;
- wherein the gate dielectric comprises a lanthanide series material in a top portion thereof.
A method of forming a semiconductor device, comprising:
- forming a gate dielectric over a semiconductor body;
- forming a silicon based gate electrode over the gate dielectric;
- introducing a lanthanide series material into the gate electrode;
- and
- driving the lanthanide series material into the gate dielectric.
Dependencies are inferred from the claim text.