Hard mask removal during FinFET formation
AssigneeGlobalfoundries Inc.
InventorMichael D. Wedlake
Life of this patent
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Abstract
An approach for polishing-based hard mask removal during FinFET device formation is provided. In a typical embodiment, an initial device will be provided with a set of fins (e.g., silicon (Si)), a set of fin caps (e.g., silicon nitride (SiN)), and an oxide layer. A post-oxide planarizing and thinning polishing will first be performed (e.g., using a Silica-based slurry) to thin/reduce the oxide layer. A stop-on-nitride polishing will then be performed (e.g., using a Ceria-based slurry) to reduce the oxide layer to a top surface of the fin caps. Still yet, a stop-on-silicon polishing will be performed (e.g., using a Ceria-based slurry) to remove the set of fin caps and to reduce the oxide layer to a top surface to the set of fins.
Claims18
A method for polishing a semiconductor device, comprising:
- performing a first polishing of a semiconductor device to thin an oxide layer over a set of fins of the semiconductor device, the set of fins having a set of silicon nitride (SiN) caps;
- performing a second polishing of the semiconductor device to reduce the oxide layer selective to a top surface of the set of SiN caps;
- and
- performing a third polishing of the semiconductor device to further reduce the oxide layer and to remove the set of SiN caps from the set of fins.
A method for polishing a semiconductor device, comprising:
- forming a set of fins in a substrate, the set of fins having a set of silicon nitride (SiN) caps;
- performing a first polishing of the semiconductor device to thin an oxide layer over the set of SiN fins;
- performing a second polishing of the semiconductor device to reduce the oxide layer selective to a top surface of the set of SiN caps on the set of fins;
- and
- performing a third polishing of the semiconductor device to further reduce the oxide layer and to remove the set of SiN caps from the set of fins.
A method for polishing a FinFET device, comprising:
- performing a planarizing polishing of the FinFET device using at least one slurry to thin an oxide layer over a set of fins of the FinFET device, the set of fins having a set of silicon nitride (SiN) caps on a top surface thereof, and the at least one slurry having differing nitride, oxide, and silicon polishing rates;
- performing a post-selective stop-on-nitride polishing of the FinFET device using the at least one slurry to reduce the oxide layer selective to a top surface of the set of SiN caps on the set of fins;
- and
- performing a post-selective stop-on-silicon polishing of the FinFET device using the at least one slurry to further reduce the oxide layer and to remove the set of SiN caps from the set of fins.
Dependencies are inferred from the claim text.