INSPECTION METHOD AND TEMPLATE

摘要

An inspection method for inspecting a substrate by using an optical image obtained by irradiating the substrate with light from a light source through an optical unit, and causing the light reflected by the substrate to be incident to a sensor, includes adjusting a focus offset value such that a focal distance for setting the signal-to-noise ratio of a programmed defect to the maximum level, is obtained by acquiring the optical image while changing a focal distance between the surface in which a first pattern is provided and the optical unit. The substrate includes the first pattern, a second pattern on the same plane as the first pattern, the programmed defect in the second pattern, and a third pattern on the same plane as the first pattern. The existence of a defect is detected by acquiring the optical image of the first pattern after the focus offset is adjusted.

主权项

1. An inspection method for inspecting a substrate to detect the existence of a defect using an optical image obtained by irradiating a substrate with light emitted from a light source through an optical unit, and causing the light reflected by the substrate to be incident to a sensor through the optical unit,
wherein the substrate includes a first pattern consisting of a repetitive pattern that is finer than the resolution limit of the optical unit; a second pattern arranged on the same plane as the first pattern, having the same direction as the first pattern, and consisting of a repetitive pattern that is finer than the resolution limit of the optical unit; a programmed defect disposed in the second pattern, finer than the resolution limit of the optical unit; and a third pattern arranged on the same plane as the first pattern, having a shape reflecting the direction of the first pattern, not finer than the resolution limit of the optical unit, the inspection method comprising: adjusting a focus offset value such that a focal distance for setting the signal-to-noise ratio of the programmed defect to the maximum level, is obtained in an optical image of the programmed defect by acquiring the optical image while changing a focal distance between the surface in which the first pattern is provided and the optical unit; detecting the existence of a defect of the first pattern by acquiring an optical image of the first pattern after the focus offset is adjusted.