Electroless deposition method

A method of processing a substrate, comprising:

• polishing a substrate surface to expose copper features formed in a dielectric material;
• depositing a noble metal selected from the group of palladium, platinum, and combinations thereof, selectively on the exposed copper features by exposing the substrate surface to an acidic electroless solution containing a noble metal salt, an inorganic acid, and having a pH between about 1 and about 3;
• removing copper oxides from the exposed copper features;
• cleaning the substrate surface of the acidic electroless solution;
• and
• depositing cobalt or cobalt alloy on the noble metal with a cobalt electroless composition.

A method of processing a substrate comprising a dielectric material and apertures formed therein, the method comprising:

• depositing an initiation layer of a conductive material on the dielectric material and apertures formed therein by a first electroless solution comprising a noble metal salt, an inorganic acid, and a pH of about 7 or less;
• cleaning the substrate surface of the first electroless solution;
• and
• depositing a cobalt-containing layer on the initiation layer by a second electroless solution.

A method of processing a substrate having a conductive silicon-based material disposed thereon with patterned apertures formed therein, the method comprising:

• depositing an initiation layer on the substrate surface by a first electroless solution comprising a noble metal salt, an inorganic acid, and a pH of about 7 or less;
• cleaning the substrate surface of the first electroless solution;
• depositing a first metal material on the initiation layer by exposing the initiation layer to a second electroless solution;
• and
• forming a metal silicide layer by reacting the conductive silicon-based material and the first metal layer using one or more annealing processes.