| 摘要 |
An insulating portion has a first region, a second region, and a third region in the stated order from the silicon portion side, the nitrogen concentration of the first region is lower than the nitrogen concentration of the second region and the oxygen concentration of the first region, the nitrogen concentration of the third region is lower than the nitrogen concentration of the second region and the oxygen concentration of the third region, and the thickness of the first region is larger than the thickness of the third region. |
