Polishing method
AssigneeRenesas Technology Corp.
InventorsSeiichi Kondo, Yoshio Homma, Noriyuki Sakuma, Kenichi Takeda, Kenji Hinode
Life of this patent
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Abstract
A polishing technique wherein scratches, peeling, dishing and erosion are suppressed, a complex cleaning process and slurry supply/processing equipment are not required, and the cost of consumable items such as slurries and polishing pads is reduced. A metal film formed on an insulating film comprising a groove is polished with a polishing solution containing an oxidizer and a substance which renders oxides water-soluble, but not containing a polishing abrasive.
Claims3
A polishing method for removing at least part of a metal film on an insulating film, comprising:
- chemically mechanically polishing the metal film on the insulating film using a polishing solution which additionally has included therein less than 1 wt % of a polishing abrasive, and includes an oxidizer, a substance which renders an oxide water-soluble, and a surfactant, said solution having a pH and oxidation-reduction potential in the domain of corrosion of said metal film,
- wherein the surfactant is mechanically rubbed out from a surface of the metal film and a metal oxide is made soluble to a substance for polishing the metal film, and
- wherein said metal film is one selected from the group consisting of a tungsten film a tungsten alloy film, and a tungsten compound film having tungsten as its principal component.
A method for manufacturing a semiconductor device, comprising:
- providing a substrate which includes a semiconductor;
- forming an insulating film on said substrate, said insulating film having an opening;
- forming a metal film inside said opening and overlying said insulating film;
- and
- polishing said metal film by chemical mechanical polishing using a polishing solution which additionally has included therein less than 1 wt % of a polishing abrasive, said solution having a pH and oxidation-reduction potential in the domain of corrosion of said metal film, said polishing solution including an oxidizer, a substance which renders a metal oxide water-soluble, and a surfactant, wherein the surfactant is mechanically rubbed out from a surface of the metal film, and a metal oxide is made soluble to a substance for polishing the metal film;
- and
- wherein said metal film is one selected from the group consisting of a tungsten film, a tungsten alloy film, and a tungsten compound film having tungsten as its principal component.
A method of manufacturing semiconductor devices, comprising:
- preparing a substrate having an impurity-doped layer
- forming an insulating film having an opening exposing said impurity-doped layer
- forming a layered film comprising a metal film having titanium nitride and copper as its principal components on the substrate on which said insulating film is formed;
- and
- mechanically rubbing a substance which suppresses etching or oxidation on said layered film surface by using a polishing solution comprising less than 0.01 wt % of an alumina polishing abrasive, hydrogen peroxide, citric acid or malic acid, and a substance which suppresses etching or oxidation, said solution having a pH and oxidation-reduction potential in the domain of corrosion of said layered film.
Dependencies are inferred from the claim text.