METHOD FOR CRITICAL DIMENSION SHRINK USING CONFORMAL PECVD FILMS
First Claim
1. A method of reducing critical dimension of a recess having sidewalls and a bottom portion formed in a substrate having a field region, comprising:
- applying a conformal layer over the field region, sidewalls, and bottom portion;
removing the conformal layer from the bottom portion by a directional etch process to expose the substrate;
etching the exposed substrate at the bottom portion; and
removing the conformal layer by a wet etch process.
1 Assignment
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Accused Products
Abstract
A method and apparatus for forming narrow vias in a substrate is provided. A pattern recess is etched into a substrate by conventional lithography. A thin conformal layer is formed over the surface of the substrate, including the sidewalls and bottom of the pattern recess. The thickness of the conformal layer reduces the effective width of the pattern recess. The conformal layer is removed from the bottom of the pattern recess by anisotropic etching to expose the substrate beneath. The substrate is then etched using the conformal layer covering the sidewalls of the pattern recess as a mask. The conformal layer is then removed using a wet etchant.
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Citations
24 Claims
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1. A method of reducing critical dimension of a recess having sidewalls and a bottom portion formed in a substrate having a field region, comprising:
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applying a conformal layer over the field region, sidewalls, and bottom portion; removing the conformal layer from the bottom portion by a directional etch process to expose the substrate; etching the exposed substrate at the bottom portion; and removing the conformal layer by a wet etch process. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method of forming a via in a field region of a substrate, comprising:
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patterning a layer formed on a surface of the substrate to form a recess having sidewalls and a bottom portion; reducing the width of the recess by applying a conformal film over the layer; forming a reduced critical dimension area by removing the conformal film from the bottom portion of the recess to expose a portion of the substrate; and etching the reduced critical dimension area to form the via. - View Dependent Claims (16, 17, 18, 19, 20, 21)
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22. A method of patterning a dielectric layer formed on a substrate, comprising:
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forming a pattern transfer layer over the dielectric layer; patterning the pattern transfer layer by applying a photoresist, patterning the photoresist, and etching the pattern into the pattern transfer layer to form a recess having a bottom portion; depositing a first conformal layer over the pattern transfer layer; removing the first conformal layer from the bottom portion of the recess to expose the dielectric layer; etching the exposed portion of the dielectric layer to form a narrow recess; removing the pattern transfer layer and the conformal layer; depositing a second conformal layer over the substrate; and removing the second conformal layer from the bottom portion of the narrow recess. - View Dependent Claims (23, 24)
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Specification