| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that a pore 26 is easy formed since an entrance is narrower than a back in the cross sectional form of a trench 24 in a conventional manner so that, if the trench 24 of this form is filled with an insulating matter 25, the entrance of the trench 24 is closed before the entire trench 24 is filled with the insulating matter 25, and the problem that the pore 26 bursts up and the trench 24 is broken when a silicon substrate 21 is heated in a post- process. SOLUTION: The surface of a silicon substrate 11 is overlaid with an oxide film 12, a nitride film 13 and a resist pattern 14 in this order. A hole is formed in the oxide film 12 and the nitride film 13. Only the oxide film 12 is lightly etched to make its hole slightly larger than the hole of the nitride film 13, so that the canopy top of the nitride film 13 is formed. With the oxide film 12 and the nitride film 13 as masks, a trench of a cross sectional form whose entrance is wider than a back is formed in the silicon substrate 11. COPYRIGHT: (C)2003,JPO
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