Method for cleaning the surface of a substrate
AssigneeAdvanced Micro Devices, Inc.
InventorsFrank Koschinsky, Volker Kahlert, Peter Huebler
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Abstract
A cleaning process for cleaning the surface of a substrate is disclosed, wherein the surface comprises portions of a dielectric material and portions of a conductive material. According to the method disclosed, the temperature at the surface of the substrate is kept below a predefined value during the actual cleaning step in a reactive and/or inert plasma ambient, such as an argon gas ambient, wherein the predefined value corresponds to the surface temperature at which agglomeration of the conductive material occurs.
Claims34
A method of cleaning the surface of a substrate, said surface comprising a portion of a dielectric material and a portion of a conductive material, the method comprising:
- a first step of degassing the substrate to promote out-gassing of contaminants, wherein degassing the substrate further comprises:
- degassing the substrate over a plurality of degassing intervals;
- and
- interrupting the degassing between each degassing interval to allow cooling of the substrate;
- a second step of pre-cleaning the surface of the substrate by establishing at least one of an inert and a reactive ambient;
- and
- wherein a surface temperature of said substrate is kept below a predefined first temperature during said second step to inhibit agglomeration of the conductive material.
A method of forming vias in a dielectric layer formed over a metal line on a substrate, said method comprising:
- etching said vias in said dielectric layer according to a predefined layout to connect to said metal line;
- cleaning said substrate;
- wherein cleaning the substrate comprises:
- a first step of degassing the substrate to promote out-gassing of contaminants, wherein degassing the substrate further comprises:
- degassing the substrate over a plurality of degassing intervals;
- and
- interrupting the degassing between each degassing interval to allow cooling of the substrate;
- a second step of pre-cleaning the surface of the substrate by establishing at least one of a reactive and an inert plasma ambient, and
- wherein the surface temperature of said substrate is kept below a predefined first temperature Ta during said second step to reduce agglomeration of the metal in said vias when etching said vias.
A method of forming metal lines on the surface of a substrate, said method comprising:
- forming a dielectric layer on the surface of said substrate;
- forming an opening in said dielectric layer by etching;
- cleaning said substrate;
- wherein cleaning the substrate comprises:
- a first step of degassing the substrate to promote out-gassing of contaminants, wherein degassing the substrate further comprises:
- degassing the substrate over a plurality of degassing intervals;
- and
- interrupting the degassing between each degassing interval to allow cooling of the substrate;
- a second step of pre-cleaning the surface of the substrate by establishing a reaction plasma ambient;
- wherein the surface temperature of said substrate is kept below a predefined first temperature Ta so that, when dielectric material is etched away in correspondence of a metal layer below the dielectric material to uncover a portion of said metal layer, agglomeration of the metal of the metal layer is substantially prevented;
- forming a barrier metal layer on said opening;
- and
- filing said opening with a conductive material.
Dependencies are inferred from the claim text.