| 摘要 |
PURPOSE: A method for setting up an optimum focus in a wafer exposure process is provided to improve yield by easily inspecting an optimum focus state of an exposure pattern so that a re-work is reduced in an exposure process of a pattern having insufficient process margin. CONSTITUTION: An optimum focus reference pattern of an exposed focus inspecting pattern is set up. An exposure process is performed regarding a wafer by using a Levinson-type phase shift mask having the focus inspecting pattern. The exposure pattern on the wafer is compared with a reference pattern. If the comparison result is an insufficient focus exposure pattern or over-focus exposure pattern, a focus is set up again. The second exposure process is performed by using the Levinson-type phase shift mask having the focus inspecting pattern. The exposure pattern on the secondly-exposed wafer is compared with the reference pattern. The focus is set up as an optimum focus if the comparison result is an optimum focus exposure pattern not greater than a limited value.
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