PECVD and CVD processes for WNx deposition

摘要

Improvements to chemical vapor deposition processes are taught for depositing tungsten nitride in semiconductor manufacturing processes. In one irmproved process NF3 is used as a source of nitrogen, and a plasma is introduced under controlled conditions to control particle formation and lower the temperature at which acceptable films may be produced. In another set of processes substantially pure tungsten is produced by rapid thermal annealing of substantially amorphous tungsten nitride at temperatures lower than achieved in the art, by using hydrogen in the ambient atmosphere. In yet another set of new processes particle formation and step coverage enhancement when using NH3 as a nitrogen source is controlled by limiting the pressure at which source gases mix, by unique wall coating technique, and by controlling chamber wall temperature. In still another set of unique processes a graded film on oxide, starting with tungsten silicide quickly grading to tungsten nitride is produced by introducing silane in the NH3 chemistry under controlled conditions.