| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent drop of alignment precision by allowing at least a part of the alignment mark provided on a substrate to protrude above a substrate surface. SOLUTION: A nitride film 3 is formed on a pad oxide film 2 formed on an Si substrate 1, on which a photo-resist element separation pattern is formed. Then, the nitride film 3 and the pad oxide film 2 are sequentially ion-etched, reactive anisotropically, to expose the Si substrate 1. Then, after the photo-resist is released, the Si substrate 1 is anisotropically etched with the nitride film 3 as a mask to form a groove 4. Then, with the nitride film 3 as a mask, the Si substrate 1 is thermally oxidized to form a thermal oxide film 5 on a side wall and a bottom surface of the groove 4. Then a CVD oxide film 6 is deposited to bary the groove 4 appropriately, and CMP is so performed as to expose the nitride film 3 for flattened CVD oxide film 6. Then, etching is performed using a mask wherein a photo-resist 7 is patterned, to adjust the height of the upper surface of the CVD oxide film 6.</p> |
