A New Photolithography Technique with Antireflective Coating on Resist: ARCOR

A new photolithography technique called antireflective coating on resist (ARCOR) is described. This method improves linewidth accuracy and overlay accuracy by decreasing the multiple interference effect in a resist film. A clear anti‐reflective film is spun on a photoresist prior to alignment pattern detection and exposure. The film is subsequently removed and the resist developed in the conventional way. Multiple reflection in a resist film is suppressed by this antireflective film, thus enabling patterning and alignment without disturbance caused by multiple interference. With this method, linewidth accuracy becomes 0.03 μm, about one–tenth that of the conventional method, and the alignment signal is improved.