Imaging device and method of manufacturing the same

A method of manufacturing an imaging device having a waveguide, comprising the steps of:

• defining a pixel region, a peripheral circuit region, and a seal ring region continuously enclosing the pixel region and the peripheral circuit region over a semiconductor substrate;
• forming a wiring structure and a pad electrode in the peripheral circuit region by forming an interlayer insulating film and a conductive film sequentially and patterning each of them, and forming a seal ring in the seal ring region;
• forming an insulating film over the semiconductor substrate so as to cover the pixel region, the pad electrode, and the seal ring;
• forming a pattern of a first photoresist exposing a first region of the insulating film located right above the pad electrode and a second region including a right-above portion of the insulating film located right above the seal ring;
• subjecting etching treatment to the exposed first and second regions of the insulating film using the first photoresist as an etching mask;
• after removing the first photoresist, forming a pattern of the second photoresist covering a region including the first and second regions of the insulating film and exposing a third region of the insulating film located in the pixel region;
• and
• forming a waveguide holding hole in the pixel region by subjecting etching treatment to the exposed third region of the insulating film using the second photoresist as an etching mask.