| 摘要 |
PURPOSE:To reduce the degradation of mark signal intensity and obtain high alignment accuracy even if thick resist is applied to the mark by a method wherein the atomic number of at least one of the elements of which mark material is composed is larger than the atomic numbers of any of the elements of which a substrate is composed and the cross-section of the mark is a T-shape to the direction vertical to the surface of the substrate. CONSTITUTION:Two layers of resists with different sensitivities are applied to an Si substrate to form a specimen and the specimen is exposed to an electron beam. The upper layer resist has high sensitivity and the lower layer resist has low sensitivity. The thickness of the upper layer is 0.5 mum and the thickness of the lower layer is 0.3 mum and the exposure is carried out with an acceleration voltage of 25 kV and dosage of 80 muc/cm<2>. Then the specimen is dipped in development solution exclusive for the low sensitivity resist for 2 minutes to obtain the cross-section as shown in Fig. (b) after development. Then an Au film with 0.5 mum thickness is formed by EB evaporation as shown in Fig. (c) and, by lifting-off with trichloroethylene, an alignment mark with a T-shape cross-section can be obtained as shown in Fig. (d).
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