METHODS OF FILLING HIGH ASPECT RATIO FEATURES WITH FLUORINE FREE TUNGSTEN

摘要

Provided herein are methods and apparatus for depositing and etching tungsten. The methods involve using tungsten chlorides (WCl_x) as both precursor and etchant. In some embodiments, the exposing the substrate to a WCl_x precursor and a reducing agent at a first set of conditions to deposit a first tungsten layer in a feature on a substrate; and exposing the substrate to a WCl_x precursor and a reducing agent at a second set of conditions to etch the first tungsten layer. According to various embodiments, transitioning from a deposition to etch regime can involve one or more of increasing a WCl_x flux, decreasing a temperature, and changing the WCl_x precursor. Also provided are related apparatus.