Methods of etching a tungsten layer
AssigneeApplied Materials, Inc.
InventorsAMRITA B. MULLICK, ISMAIL EMESH, UDAY MITRA, ROEY SHAVIV, REGINA FREED
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Abstract
Methods of etching tungsten are disclosed including: leveling a first top surface of a tungsten layer within a feature and atop a top surface of a substrate; and etching the tungsten layer with a peroxide such as hydrogen peroxide and one of a strong acid or a strong base to remove a first portion of the tungsten layer from atop the substrate to form a second top surface of a tungsten layer at a level below the top surface of the substrate. The methods are suitable for forming substantially level or flat top surfaces of a tungsten layer at a level below the top surface of the substrate or within one or more features such as vias or trenches.
Claims20
A method of etching tungsten, comprising:
- leveling a first top surface of a tungsten layer within a feature and atop a top surface of a substrate;
- and
- etching the tungsten layer with a hydrogen peroxide and one of a strong acid or a strong base to remove a first portion of the tungsten layer from atop the substrate to form a second top surface of a tungsten layer at a level below the top surface of the substrate.
A method of etching tungsten, comprising:
- planarizing a top surface of a tungsten layer disposed atop a substrate and above a feature formed in a dielectric layer of the substrate to form a first level top surface of the tungsten layer above the feature;
- and
- contacting the first level top surface of the tungsten layer with an etch solution comprising an oxidizing agent and one of a strong acid or strong base for a time sufficient to etch the first level top surface of the tungsten layer to form a second level top surface of the tungsten layer within the feature.
A method of etching a tungsten layer disposed on a substrate, comprising:
- contacting a substantially level first top surface of a tungsten layer with an etch solution comprising hydrogen peroxide, and optionally one of a strong acid or a strong base for a time sufficient to etch the substantially level first top surface of the tungsten layer to form a substantially level second top surface within a feature disposed in the substrate, wherein the feature has a high aspect ratio and a width of less than 20 nanometers.
Dependencies are inferred from the claim text.