Role of film conformality in charging damage during plasma-assisted interlevel dielectric deposition

While observations of charging damage during plasma-assisted deposition have been erratic thus far, concern abounds that it may worsen as aspect ratios increase and high-density plasmas are used more frequently. Simulations of pattern-dependent charging during interlevel dielectric deposition reveal that the initial conformality of the dielectric film plays a crucial role in metal line charge up and the subsequent degradation to the buried gate oxide, to which the metal line is connected. For moderate aspect ratios, significant charging damage occurs for nonconformal step coverage.