Method for depositing refractory metal layers employing sequential deposition techniques

A method for forming a tungsten layer on a substrate surface, comprising:

• exposing a substrate surface comprising titanium nitride to diborane for less than 30 seconds at about 1 to about 5 Torr and between about 300° C. and about 350° C.;
• depositing a nucleation layer by alternately pulsing a tungsten-containing compound and silane gas at the same process conditions;
• and
• forming a bulk tungsten deposition film on the nucleation layer.

A method for forming a tungsten layer on a substrate surface, comprising:

• positioning the substrate surface in a processing chamber;
• exposing the substrate surface to a boride;
• depositing a nucleation layer in the same processing chamber by alternately pulsing a tungsten-containing compound and silane gas;
• and
• forming a bulk tungsten deposition film on the nucleation layer.