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US 4,050,954 AGranted
Surface treatment of semiconductor substrates
AssigneeInternational Business Machines Corporation
InventorJagtar S. Basi
Life of this patent
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Abstract
The invention comprehends establishing a hydrophilic surface on polished semiconductor wafers, such as silicon, after polishing (e.g. silica polishing) by oxidation and hydrolysis of the wafer surface for conditioning thereof for post-polishing cleaning.
Claims13
In a method of cleaning a silicon wafer polished with a metal oxide polishing medium, the improvement comprising:
- establishing hydrophilic surfaces on said wafer by oxidation thereof with an oxidizing agent selected from the group consisting of alkali metal hypohalites, and dichromates and permanganate salts of alkali metals in sulfuric acid, and including the step of treating the hydrophilic formed surfaces with an NH.sub.4 OH solution.
In a method of cleaning silicon wafers polished with a metal oxide polishing medium, the improvement comprising:
- a. establishing hydrophilic surfaces on said wafers by oxidation with an oxidizing agent selected from the group consisting of alkali metal hypohalites, and dichromate and permanganate salts of alkali metals in sulfuric acid;
- b. treating said hydrophilic surfaces with an NH.sub.4 OH solution to remove metal ions therefrom remaining from said polishing medium,
- c. establishing hydrophobic surfaces on said wafers by treatment with hydrofluoric acid solution and concurrently removing oxides therewith from said surfaces;
- and
- d. reconverting said surfaces to a hydrophilic condition with re-treatment with said oxidizing agent.
2 more elements
Dependencies are inferred from the claim text.