Removal of surface passivation
Methods for removing a passivation film from a copper surface can include exposing the passivation film to a vapor phase organic reactant, for example at a temperature of 100° C. to 400° C. In some embodiments, the passivation film may have been formed by exposure of the copper surface to benzotriazole, such as can occur during a chemical mechanical planarization process. The methods can be performed as part of a process for integrated circuit fabrication. A second material can be selectively deposited on the cleaned copper surface relative to another surface of the substrate.
1. A method for removing at least a portion of a passivation film from a substrate surface comprising a first metal surface and a second dielectric surface, the method comprising:
exposing the passivation film to a vapor phase organic reactant that is an alcohol, an aldehyde or has the formula R—COOH, where R is hydrogen or a C1 to C3 alkyl,
wherein the passivation film was formed by exposure of the first metal surface to a passivation agent comprising a hydrocarbon, and
wherein the passivation film is not exposed to a plasma during exposure of the passivation film to the vapor phase organic reactant, and
selectively depositing a material on the first metal surface relative to the second dielectric surface.
2. The method of claim 1 , wherein the passivation film is exposed to the vapor phase organic reactant at a temperature of 100° C. to 400° C.
3. The method of claim 1 , wherein the vapor phase organic reactant comprises carboxylic acid.
4. The method of claim 1 , wherein the vapor phase organic reactant comprises formic acid.
5. The method of claim 1 , wherein the passivation agent comprises an aromatic hydrocarbon.
6. The method of claim 1 , wherein the passivation agent comprises benzotriazole.
7. The method of claim 1 , further comprising repeating exposing the passivation film to the vapor phase organic reactant at least 10 times.
8. The method of claim 1 , wherein the metal surface is a copper surface.
9. The method of claim 1 , wherein a surface chemistry of the second dielectric surface is substantially unaffected by exposing the passivation film to the vapor phase organic reactant.