Metal silicide gate transistors
AssigneeAdvanced Micro Devices, Inc.
InventorsQi Xiang, Paul R. Besser, Matthew Buynoski, John C. Foster, Paul L. King, Eric N. Paton
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Abstract
A method for implementing a self-aligned metal silicide gate is achieved by confining a metal within a recess overlying a channel and annealing to cause metal and its overlying silicon to interact to form the self-aligned metal silicide gate. A gate dielectric layer formed of oxynitride or a nitride/oxide stack is formed on the bottom and sidewalls of the recess prior to depositing the silicon. The metal is removed except for the portion of the metal in the recess. A planarization step is performed to remove the remaining unreacted silicon by chemical mechanical polishing until no silicon is detected.
Claims27
A method for forming a semiconductor structure comprising the steps of:
- forming a precursor having a substrate with active regions separated by a channel, and a temporary gate over the channel and between dielectric structures;
- removing the temporary gate to form a recess with a bottom and sidewalls between the dielectric structures;
- depositing a gate dielectric formed of oxynitride in the recess on the bottom and sidewalls;
- depositing a metal over the gate dielectric and on the dielectric structures;
- removing the metal except for a portion in the recess;
- depositing amorphous silicon over the metal and on the dielectric structures;
- annealing to cause the amorphous silicon and the portion of the metal in the recess to react to form a self-aligned metal suicide gate;
- and
- planarizing to remove the amorphous silicon on the dielectric structures.
A method for forming a semiconductor structure comprising the steps of:
- forming a precursor having a substrate with active regions separated by a channel, and a temporary gate over the channel and between dielectric structures;
- removing the temporary gate to form a recess with a bottom and sidewalls between the dielectric structures;
- depositing a gate dielectric formed of a nitride/oxide stack in the recess on the bottom and sidewalls;
- depositing a metal over the gate dielectric and on the dielectric structures;
- removing the metal except for a portion in the recess;
- depositing amorphous silicon over the metals and on the dielectric structures;
- annealing to cause the amorphous silicon and the portion of the metal in the recess to react to form a self-aligned metal silicide gate;
- and
- planarizing to remove the amorphous silicon on the dielectric structures.
Dependencies are inferred from the claim text.