| 摘要 |
PURPOSE:To maintain productivity at high level even when semiconductor chips, having high degree of integration and shallow depth of focal point, are manufactured. CONSTITUTION:The standard height of the surface to be exposed of a wafer is determined immediately after placement of the wafer 14 on a moving base 15. The below-mentioned procedures are repeated on the respective expected surface for chip formation 14a, which is the surface to be exposed of the wafer for formation of semiconductor chips. The height of the point of image, stored in advance in a lens system 13 in accordance with chip size, is read out. On a plurality of sample points, the relative height from the standard height ZO is measured. The average height Za of the surface to be exposed of the wafer is computed from each value. Lastly, an exposing operation is conducted by matching the surface to be exposed of the wafer to the average height. |
