Design dependency of yield loss due to tungsten residues in spin on glass based planarization processes

In spin on glass (SOG) planarization processes yield loss can occur in between closely spaced metal lines due to the formation of tungsten residues called stringers. Stringers may cause electrical shorts between adjacent metal tracks, In this paper it is shown under what conditions stringers may occur and the extraction procedure capable of detecting locations prone to stringers in a product is proposed. The usefulness of such a procedure for both failure analysis and in line process monitoring is discussed as well.