Method of depositing Ru films having high density

A semiconductor device, comprising:

• a substrate;
• and
• a ruthenium film formed over the substrate, the film comprising:
• a first ruthenium layer formed over the substrate;
• and
• a second ruthenium layer formed on the first ruthenium layer,
• wherein each of the first and second ruthenium layers has a density of about 10 g/cm3 to about 13 g/cm3.

A ruthenium bilayer structure comprising:

• a first ruthenium layer formed over a substrate;
• and
• a second ruthenium layer formed directly on the first ruthenium layer,
• wherein each of the first and second ruthenium layers has a density of about 10 g/cm3 to about 13 g/cm3.

A method of depositing a ruthenium film, the method comprising:

• providing a substrate into a reactor;
• depositing a first ruthenium layer over the substrate at a first deposition rate by a plasma enhanced atomic layer deposition (PEALD) process;
• and
• depositing a second ruthenium layer over the first ruthenium layer at a second deposition rate by an atomic layer deposition (ALD) process, the second deposition rate being greater than the first deposition rate.

A method of depositing a ruthenium film, the method comprising:

• providing a substrate into a reactor;
• depositing a first ruthenium layer over the substrate by a plasma enhanced atomic layer deposition (PEALD) process;
• and
• depositing a second ruthenium layer over the first ruthenium layer by a non-plasma process, wherein the second ruthenium layer has substantially the same density as that of the first ruthenium layer.