| 摘要 |
PURPOSE:To ensure the formation of a favorable exposure pattern and to contrive the improvement in yield and the miniaturization of the pattern by diminishing a sideways encroachment of a selective oxide film in a region of arer alignment mark for an exposure pattern at the time for forming a selective oxide film. CONSTITUTION:A pattern of an Si3N4 film 3 is formed on a semiconductor substrate 1 and only the region where this Si3N4 film is not formed is oxidized selectively to effect selective oxidation. At this time, a thickness of a selective oxide film 4 is restrained to be thin enough to form an alignment mark clearly and a cover pattern 5 is made only in an alignment mark region M whereas the pattern is not made in an element region D. Accordingly, a pattern size in this case is as thick as it can cover the alignment mark region M. After forming the cover pattern 5, the selective oxidation is effected again in order to form the selective oxide film 4 having an enough thickness for the element region D. Then, by removing the pattern 5 and the Si3N4 film pattern, the region D and an alignment mark for an exposure pattern are formed. |
