Metal silicide, metal germanide, methods for making the same

A method for selective silicidation, comprising:

• providing an interface film over an exposed silicon-containing region in a manner that avoids oxidation of the exposed silicon-containing region, wherein the interface film is a material different from that of the exposed silicon-containing region;
• forming a metal oxide thin film on the interface film by CVD, pulsed CVD or at least one cycle of an atomic layer deposition (ALD) or ALD-type process, wherein one cycle comprises:
• contacting a substrate with a metal source precursor, and
• contacting the substrate with an oxygen source precursor;
• and
• reacting the metal from the metal oxide film with silicon from the silicon-containing region to form a metal silicide film over remaining portions of the silicon-containing region.

A method for forming metal germanide, comprising:

• providing a substrate having at least one exposed silicon region;
• depositing a germanium layer on the exposed silicon region;
• depositing a metal oxide film over germanium layer;
• and
• heating the substrate to form a metal germanide film using metal from the metal oxide film and a metal silicide under the metal germanide.

A method for forming a doped metal silicide layer on a substrate, comprising:

• providing a substrate having at least one exposed silicon region;
• depositing a metal film comprising a first metal over the silicon region, wherein depositing the metal film comprises multiple cycles of a primary metal atomic layer deposition-type process;
• depositing a dopant film comprising a second metal over the silicon region, wherein depositing the dopant film comprises one or more cycles of a dopant atomic layer deposition-type process;
• and
• annealing the substrate to form a metal silicide of the first metal that is doped with the second metal, wherein the cycles of the primary metal atomic layer deposition-type process and the cycles of the dopant atomic layer deposition-type process are carried out at a specific ratio to achieve a desired dopant concentration in the doped metal silicide layer.