PHASE SHIFT MASK AND ITS INSPECTION METHOD

摘要

PURPOSE:To measure and inspect the transmittance error and phase shift angle errors of phase shifters on the phase shift mask by measuring the width of the resist patterns transferred onto a wafer by stepping using the phase shift mask. CONSTITUTION:Periodic line and space patterns are formed by a chrome on a glass substrate 1 and further, the phase shifters 3 are arranged at every other one in light transmission parts. A resist 5 applied on the wafer 4 is exposed by i rays 4 through the phase shift mask and is developed while the focus is changed. The width Ws of the resist patterns formed on the wafer 4 by exposing through the phase shifters 3 and the width Wo of the resist patterns formed by exposing not through the phase shifters 3 are then measured. The transmittance errors and phase shift angle errors of the phase shifters 3 are measured by a relation between Ws and Wo with respect to defocusing.