Method of removing etch residues
AssigneeMicron Technology, Inc.
InventorsLarry Hillyer, Max F. Hinerman
Life of this patent
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Abstract
Organic etch residues are often left within vias formed by etching through resist masks. Since the etch is designed to expose an underlying metal layer and is directional in order to produce vertical via sidewalls, the residue often incorporates metal. The present invention discloses a method of removing such etch residues while passivating exposed metal, including exposing the residue to ammonia. In the disclosed embodiment, ammonia and oxygen are mixed in a plasma step, such that the resist can be burned off at the same time as the residue treatment. The residue can thus be easily rinsed away.
Claims20
A method of forming and cleaning a via in a partially fabricated integrated circuit having a top, wherein the integrated circuit comprises a metal layer, an anti-reflective coating above the metal layer, and a dielectric layer above the anti-reflective coating, the method comprising:
- depositing an organic resist layer on the top of the partially fabricated integrated circuit;
- forming an opening in the resist layer;
- etching a via through the opening in the resist layer, wherein the via extends through the dielectric layer and the anti-reflective coating, thereby exposing the metal layer;
- and
- cleaning the via by exposing the via to a plasma that simultaneously removes the resist layer, wherein the plasma is formed from a gas comprising ammonia.
A method of forming and cleaning a void in a partially fabricated integrated circuit comprising:
- depositing a resist layer on a top of the partially fabricated integrated circuit;
- forming an aperture in the resist layer;
- etching a void through the aperture in the resist layer and through an underlying dielectric layer to expose a metal layer, thereby forming a residue in the void;
- and
- removing the resist layer and the residue from the void by exposing the partially fabricated integrated circuit to a plasma formed from a gas comprising ammonia and rinsing the exposed void.
Dependencies are inferred from the claim text.