| 摘要 |
Process for the manufacture of calibration structures comprises (i) applying a first material (2) and a first photoresist (3) to a substrate, exposing to a first mask, developing and etching to produce images (2', 2") of the first material, (ii) applying a second material (5) and a second photoresist (6) over the images, exposing to a second mask, developing and etching to produce images (5', 5", 5"') of the second material on the first material images (2', 2") and on the substrate (1). The overhang (2a, 2b) of the images (2', 2") may be removed by etching, a third photoresist (7) may be applied and exposed to a third mask so that images (5', 5'") can be removed to leave image (5") between images (2', 2") so that calibration structures are provided in which the misalignment of the first layer with respect to the second layer is set to a known extent by means of the first masking step. Alternatively, the overhangs (2a, 2b) may be removed before the remaining second photoresist (6', 6", 6'") is removed or after the third photoresist (7) has been masked. <IMAGE>
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