| 摘要 |
The invention relates to an inspection method for inspecting a surface pattern (4) formed on a front side of a substrate (3), preferably of a sapphire wafer, the method comprising the steps of:
(a) irradiating , with first light (1), preferably having different wavelengths, a first area of the surface pattern (4) from the front side of the substrate (3);
(b) measuring at least one characteristic of said first light (1) after having interacted with the surface pattern (4), preferably by diffraction;
(c) irradiating , with second light (2), preferably having different wavelengths, a second area of the surface pattern (4) through the back side of the substrate (3), wherein the first area and the second area at least partially, preferably completely, overlap with each other;
(d) measuring at least one characteristic of said second light (2) after having interacted with the surface pattern (4), preferably by diffraction;
(e) calculating a quantity (T) containing information about at least one geometric property of the surface pattern (4) of the substrate (3), wherein the quantity (T) is a function of both, the characteristic of the first light (1) measured in step (b) and the characteristic of the second light (2) measured in step (d). |
