Method of fabricating high density sub-lithographic features on a substrate
AssigneeHewlett-Packard Development Company, L.P.
InventorThomas C. Anthony
Life of this patent
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Abstract
A method of fabricating high density sub-lithographic features is disclosed. The method includes the use of common microelectronic processes including sub-lithographic spacer formation and Damascene processes to form a plurality of sub-lithographic spacers on vertical side wall surfaces of features carried by a substrate. The sub-lithographic spacers have a period that is less than a minimum resolution of a lithographic system. The density of features, including the sub-lithographic spacers, within a minimum resolution of the lithographic system, can be increased by subsequent depositions of material, followed by anisotropic etching to selectively remove horizontal surfaces of the deposited material. Optionally, the spacer materials can be conformally deposited.
Claims20
A method of fabricating high density sub-lithographic features, comprising:
- depositing a mask layer on a substrate;
- patterning the mask layer to define an image thereon including a minimum feature size that is greater than or equal to a minimum resolution of a lithographic system used for the patterning;
- etching the substrate to transfer the image to the substrate thereby defining a feature thereon, the feature including the minimum feature size, a horizontal surface positioned entirely within the substrate, and vertical side wall surfaces extending to the horizontal surface;
- depositing a spacer material on the horizontal and vertical side wall surfaces until the spacer material has a predetermined thickness that is less than the minimum feature size;
- increasing a density of features within the minimum feature size by anisotropically etching the spacer material to selectively remove the spacer material from the horizontal surfaces so that the spacer material remains on the vertical side wall surfaces and defines a plurality of sub-lithographic spacers thereon, the sub-lithographic spacers including a thickness that is less than the minimum feature size;
- and
- further increasing the density of features within the minimum feature size until a desired density of features is obtained by repeating the depositing and the anisotropically etching to define additional sub-lithographic spacers on previously defined sub-lithographic spacers, the additional sub-lithographic spacers including a thickness that is less than the minimum feature size.
A method of fabricating high density sub-lithographic features, comprising:
- depositing a feature layer on a surface of a substrate;
- patterning and then etching the feature layer to define a plurality of features extending outward of the substrate and including a horizontal surface, opposed vertical side wall surfaces, and a minimum feature size that is greater than or equal to a minimum resolution of a lithographic system used for the patterning;
- depositing a spacer material on the horizontal surface and on all of the vertical side wall surfaces of the plurality of features until the spacer material has a predetermined thickness that is less than the minimum feature size;
- increasing a density of features within the minimum feature size by anisotropically etching the spacer material to selectively remove the spacer material from the horizontal surfaces so that the spacer material remains on all of the vertical side wall surfaces and defines a plurality of sub-lithographic spacers thereon, the sub-lithographic spacers including a thickness that is less than the minimum feature size;
- and
- further increasing the density of features within the minimum feature size until a desired density of features is obtained by repeating the depositing and the anisotropically etching to define additional sub-lithographic spacers on previously defined sub-lithographic spacers, the additional sub-lithographic spacers including a thickness that is less than the minimum feature size.
Dependencies are inferred from the claim text.