OPTIMIZING I-LINE LITHOGRAPHY FOR 0.3-MU-M POLY-GATE MANUFACTURING

With advanced steppers and resists, i-line lithography (365 nm) is cap able of printing sub-0.35-mu m geometries. Individual and overlapping process windows for grouped and isolated 0.3- and sub-0.3-mu m lines w ere optimized, using advanced resists and bottom antireflected coating (BARC). The entire poly-gate patterning sequence, including process c haracterization by scanning electron microscope (SEM) inspection after resist development, BARC-dry etch, and polysilicon etch, has been inv estigated. Automated electrical linewidth measurements (ELMs) were pro ven to be a fast and reliable method to measure the after-etch process window.