Image sensor, manufacturing method thereof, and image capturing apparatus

An image capturing apparatus comprising:

• an image sensor including:
• a plurality of photoelectric conversion portions that convert light incident on a first surface of a semiconductor substrate into charge;
• a plurality of circuit portions, controlled from a second surface that is an opposite surface of the first surface of the semiconductor substrate, for transferring the charge converted by the photoelectric conversion portions;
• and
• first separation portions that separate the photoelectric conversion portions and the circuit portions for transferring the charge converted by the photoelectric conversion portions;
• and
• a processing unit that processes a signal output from the image sensor,
• wherein at least part of the first separation portions are formed such that the area of the first surface is larger than the area of the second surface at least part of the respective photoelectric conversion portions.

A manufacturing method of an image sensor comprising:

• forming, in a semiconductor substrate, first separation portions that penetrate from a first surface on which light is incident to a second surface that is opposite side of the first surface;
• forming a plurality of circuit portions that are controlled by the second surface for transferring charge converted by photoelectric conversion portions;
• forming second separation portions that separate the circuit portions and the photoelectric conversion portions;
• and
• forming the photoelectric conversion portions that converts light incident on the first surface into charge,
• wherein at least part of the first separation portions and the second separation portions are formed so that the area of the first surface is larger than the area of the second surface of at least part of the respective photoelectric conversion portions.