Methods of fabricating semiconductor fins by double sidewall image transfer patterning through localized oxidation enhancement of sacrificial mandrel sidewalls
AssigneeInternational Business Machines Corporation
InventorKangguo Cheng
Life of this patent
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Abstract
A method of fabricating semiconductor fins, including, patterning a film stack to produce one or more sacrificial mandrels having sidewalls, exposing the sidewall on one side of the one or more sacrificial mandrels to an ion beam to make the exposed sidewall more susceptible to oxidation, oxidizing the opposite sidewalls of the one or more sacrificial mandrels to form a plurality of oxide pillars, removing the one or more sacrificial mandrels, forming spacers on opposite sides of each of the plurality of oxide pillars to produce a spacer pattern, removing the plurality of oxide pillars, and transferring the spacer pattern to the substrate to produce a plurality of fins.
Claims16
A method of fabricating semiconductor fins, comprising:
- patterning a film stack to produce one or more sacrificial mandrels having sidewalls;
- exposing the sidewall on one side of the one or more sacrificial mandrels to an ion beam to make the exposed sidewall more susceptible to oxidation;
- oxidizing the opposite sidewalls of the one or more sacrificial mandrels to form a plurality of oxide pillars;
- removing the one or more sacrificial mandrels;
- forming spacers on opposite sides of each of the plurality of oxide pillars to produce a spacer pattern;
- removing the plurality of oxide pillars;
- transferring the spacer pattern to the substrate to produce a plurality of fins by etching the substrate to form trenches between the fins having varying depths;
- and
- filling the trenches with a dielectric material.
A method of fabricating semiconductor fins, comprising:
- forming a film stack on a substrate, where the film stack includes
- a nitride layer on the substrate, an oxide layer,
- a sacrificial mandrel layer,
- and a capping layer;
- patterning the capping layer and sacrificial mandrel layer to produce one or more sacrificial mandrels having sidewalls;
- exposing the sidewall on one side of the one or more sacrificial mandrels to an ion beam to make the exposed sidewall more susceptible to oxidation;
- oxidizing the sidewalls of the one or more sacrificial mandrels to form a plurality of oxide pillars;
- removing the one or more sacrificial mandrels;
- forming spacers on opposite sides of each of the plurality of oxide pillars to produce a spacer pattern;
- removing the plurality of oxide pillars;
- and
- transferring the spacer pattern to the substrate by etching the oxide layer, nitride layer and substrate.
Dependencies are inferred from the claim text.