Methods for minimizing feature-to-feature gap fill height variations

A method of gap filling a feature on a substrate, comprising:

• heating a substrate to a temperature of approximately 350 degrees Celsius to approximately 450 degrees Celsius;
• exposing the substrate to a tungsten hexafluoride gas (WF6) at a process pressure of approximately 10 Torr;
• soaking the substrate for a soak time of approximately 10 seconds with the tungsten hexafluoride gas;
• and
• performing a metal preclean process and a gap fill deposition on a plurality of features on the substrate after soak time has elapsed.

A non-transitory, computer readable medium having instructions stored thereon that, when executed, cause a method of gap filling a feature to be performed, the method comprising:

• heating a substrate to a temperature of approximately 350 degrees Celsius to approximately 450 degrees Celsius;
• exposing the substrate to a tungsten halide gas at a process pressure of approximately 5 Torr to approximately 25 Torr;
• soaking the substrate for a soak time of approximately 5 seconds to approximately 60 seconds with the tungsten halide gas;
• and
• performing a metal preclean process and a gap fill deposition on a plurality of features on the substrate after soak time has elapsed, wherein a feature-to-feature gap fill height variation of the plurality of features on the substrate is less than 9 nm.