| 摘要 |
PROBLEM TO BE SOLVED: To form an alignment mark finely on a backside irradiation type CMOS image sensor. SOLUTION: For example, a contact hole 21b penetrating an Si epitaxial layer 10 where a unit cell is formed is formed in the Si epitaxial layer 10. Its inner wall is oxidized to form a thin insulating film 21c having a substantially uniform film thickness. Low-resistance polysilicon is buried in the contact hole 21b with the insulating film 21c interposed to form a contact layer 21a, thereby forming a backside extraction electrode 21 serving as an alignment mark. COPYRIGHT: (C)2010,JPO&INPIT |
