Methods for fabricating residue-free contact openings
AssigneeMicron Technology, Inc.
InventorLi Li
Life of this patent
Estimating the term…
Abstract
A two-step via cleaning process which removes metal polymer and oxide polymer residues from a via with substantially no damage to the via or underlying structures on a semiconductor substrate. The two-step cleaning process comprises first subjecting the residue layer to a nitric acid dip which removes the metal polymer component to expose the oxide polymer component. The oxide polymer component is then subjected to a phosphoric acid dip which removes the oxide polymer component. The oxide polymer and metal polymer residues may also be removed during the fabrication of the via by removing them directly after their respective formations.
Claims54
A method of fabricating a contact opening in a dielectric layer and a barrier layer for a semiconductor device, comprising:
- providing a semiconductor substrate having a conductive pad;
- forming said barrier layer over said semiconductor substrate and said conductive pad;
- forming said dielectric layer over said barrier layer;
- forming a first via portion by anisotropic etching through said dielectric layer to expose a portion of said barrier layer, said formation of said first via portion forming an oxide polymer residue within said first via portion;
- applying a phosphoric acid containing solution within said first via portion to remove said oxide polymer residue;
- forming a second via portion by anisotropic etching through said exposed portion of said barrier layer, said formation of said second via portion forming a metal polymer residue within said first and second via portions;
- and
- applying a nitric acid containing solution within said first and second via portions to remove said metal polymer residue.
A method of fabricating a contact opening in a dielectric layer and a barrier layer for a semiconductor device, comprising:
- providing a semiconductor substrate having a conductive pad;
- forming said barrier layer over said semiconductor substrate and said conductive pad;
- forming said dielectric layer over said barrier layer;
- forming a first via portion having substantially parallel sidewalls through said dielectric layer to expose a portion of said barrier layer, said formation of said first via portion forming an oxide polymer residue within said first via portion;
- applying a solution including a fluorine containing component within said first via portion to remove said oxide polymer residue;
- forming a second via portion having substantially parallel sidewalls contiguous with said substantially parallel sidewalls of said first via portion through said exposed portion of said barrier layer, said formation of said second via portion forming a metal polymer residue within said first and second via portions;
- and
- applying nitric acid within said first and second via portions to remove said metal polymer residue.
A method of fabricating a contact opening in a dielectric layer and a barrier layer for a semiconductor device, comprising:
- providing a semiconductor substrate having a metal trace;
- forming said barrier layer over said semiconductor substrate and said metal trace;
- forming said dielectric layer over said barrier layer;
- forming a first via portion by anisotropic etching through said dielectric layer to expose a portion of said barrier layer, said formation of said first via portion forming an oxide polymer residue within said first via portion;
- forming a second via portion by anisotropic etching through said exposed portion of said barrier layer, said formation of said second via portion exposing said metal trace and forming a metal polymer residue;
- applying nitric acid within said first and second via portions to remove said metal polymer residue;
- and
- subsequently applying a solution including a fluorine containing component within said first via portion to remove said oxide polymer residue.
A method of fabricating a contact opening in a dielectric layer and a barrier layer for a semiconductor device, comprising:
- providing a semiconductor substrate having a metal trace;
- forming said barrier layer over said semiconductor substrate and said metal trace;
- forming said dielectric layer over said barrier layer;
- forming a first via portion defined by substantially parallel sidewall portions through said dielectric layer to expose a portion of said barrier layer, said formation of said first via portion forming an oxide polymer residue within said first via portion;
- applying a solution including a fluorine containing component within said first via portion to remove said oxide polymer residue;
- forming a second via portion defined by substantially parallel sidewall portions contiguous with said sidewall portions of said first via portion through said exposed portion of said barrier layer, said formation of said second via portion exposing said metal trace and forming a metal polymer residue within said first and second via portions;
- and
- applying a nitric acid containing solution within said first and second via portions to remove said metal polymer residue.
Dependencies are inferred from the claim text.