0.2 mu m or less i-line lithography by phase-shifting-mask technology

A novel phase-shifting technology has been developed for improving resolution of isolated patterns. A phase-shifter edge line (PEL) is used as an opaque mask instead of a chrome pattern. The intensity distribution of the PEL is sharper than those of chrome patterns under the same illumination conditions. 0.15 mu m wide space patterns in LMR-UV (negative resist) are delineated in the focus range of more than 1.5 mu m by using a PEL-mask and an i-line stepper. In the same manner, 0.15 mu m wide line patterns are clearly formed by use of PFR-TT15 (positive resist). In addition, a new modification adapted to hole or pillar patterns has been developed by applying double exposure with a pair of PEL-masks. By this method 0.2 mu m hole patterns in LMR-UV are successfully delineated in a wide focus latitude of 1.5 mu m.<>