Steve L. Hentschel, Henry H. Kamberian, Julius Kovatch
Oct 6, 1995
Journal name not available for this finding
Recent advances in pattern placement accuracy by photomask lithography tools are requiring much tighter repeatability specifications from the metrology equipment used in the characterization and monitoring process of these reticle writing systems. As pattern positioning accuracy specifications for the next generation tools (i.e., MEBES 4500 and ALTA 3000) dip below the 40 nanometer mark, the metrology tool must maintain a pattern placement measurement precision four times smaller than the writing tool, or less than 10 nanometers to satisfy current industry standards. The newest line width and coordinate registration metrology tool from Nikon, the Laser XY-5i, can measure photomasks and reticles with sub-10 nanometer precision. Recent acceptance test results as well as long term stability data (2-4 months) from a tool in a production environment prove the XY-5i worthy to characterize and monitor the newest mask and reticle lithography tools. A road map for future improvements and specification reduction will show the XY-5i capable of meeting the industry's metrology needs well into the 0.25 micron device generation and beyond.