| 摘要 |
<p>PURPOSE: An overlay correcting method in an extreme ultra violet system is provided to reflect the focus changing amount of a mask during overlay correction, thereby accurately correcting a magnification change due to de-focus of the mask. CONSTITUTION: A sample pattern is formed through a light exposure process using an EUV system of a non-telecentric lighting system(410). An overlay about the sample pattern is measured using an overlay measuring device(420). The focus change amount of the mask is calculated using parameters used during the light exposure process and the overlay value(430). The focus of the mask used in the light exposure process is changed according to the calculated focus change amount(440).</p> |
