Using Statistical Methods to Optimize Patterning Parameters for Tungsten Deposition

Circuit edit and failure analysis require tungsten deposition parameters to accomplish different goals. Circuit edit applications desire low resistivity values for rewiring, while failure analysis requires high deposition rates for capping layers. Tungsten deposition can be a well controlled process for a variety of beam parameters. For circuit edit, tungsten resistivity approaching below 150 µohm-cm and 50 μm³/nC is predicted. Material deposition rates of 80 μm³/nC can be achieved with reasonable pattern accuracy using defocus as a parameter.