Half-tone PSM Inspection Sensitivity of 257nm Light Source MC-3000

摘要

Binary (Chromium) and, KrF/ArF phase shift masks (PSM) were inspected by MC-3000, which uses DUV (257nm) light source, and an evaluated results of these sensitivities are shown. In the case of the chromium mask, sufficient detection sensitivity for 130nm-device inspection was obtained. For KrF and ArF phase shift masks, the detection sensitivities of the edge and the corner areas are practically equivalent to that of chromium. Though the detection sensitivity of a minute pinhole is slightly lower under the influence of the diffracted light. With an ArF phase shift mask, the contrast of absorber and a glass portion is low, and so improvement of the signal noise ratio of a sensor becomes essential for false-defect control. Additionally, the minute pinhole detection sensitivity will be higher, if a reflective inspection etc. is carried out.