Lithographic performance of SiNx single-layer halftone mask

An aging process that makes SiNx single-layer halftone film stable for DUV (248 nm) exposure has been established. The light irradiation with a low pressure mercury lamp was used to age the SiNx halftone film from the tendency of the transmittance change caused by the DUV exposure. Taking account of the optical constants shift during aging process, a SiNx halftone film with transmittance T equals 9.3%, phase shift angle (theta) equals 178 degrees was obtained. At the SiNx film, no transmittance change was observed after 2800 J/cm2 DUV exposure. Using the mask, 0.2 micrometers hole patterns were obtained with above 1.0 micrometers depth of focus (DOF).© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.