| 摘要 |
PROBLEM TO BE SOLVED: To maintain high reliability of circuit devices by properly preventing diffusion of hydrogen, moisture or the like into circuit devices such as nonvolatile memory cells. SOLUTION: A memory cell 12 is formed on a semiconductor substrate 11, and a first wiring layer 14 is formed on the memory cell 12 via a first interlayer insulating film 13. A second wiring layer 16 is formed as an upper layer of the first wiring layer 14. A TEOS oxide film 15b having a flat surface is formed between the first wiring layer 14 and the second wiring layer 16 for offsetting the difference in levels of the first wiring layer 14 and a plasma oxide film 15a, which is packed more closely than in the TEOS oxide film 15b, is formed under it. A TEOS oxide film 17b having a flat surface is formed for offsetting the difference in levels of the second wiring layer 16, in such a way that it directly covers the top and sides of the second wiring layer 16 and a plasma oxide film 17c, which is packed more closely than in the TEOS oxide film 17b and is thicker than the plasma oxide film 15a, is formed on the oxide film 17b.
|
