US 12,272,709 B2
Image sensor wherein the transfer gate contacts a first refractive layer that is coplanar with a second refractive layer
Minho Jang, Suwon-si (KR); Jeongsoon Kang, Gum-si (KR); Donghyun Kim, Hwaseong-si (KR); Seungkuk Kang, Seoul (KR); and Insung Joe, Seoul (KR)
Assigned to SAMSUNG ELECTRONICS CO., LTD., Suwon-si (KR)
Filed by SAMSUNG ELECTRONICS CO., LTD., Suwon-si (KR)
Filed on Mar. 21, 2022, as Appl. No. 17/655,576.
Claims priority of application No. 10-2021-0100683 (KR), filed on Jul. 30, 2021.
Prior Publication US 2023/0030489 A1, Feb. 2, 2023
Int. Cl. H01L 27/146 (2006.01)
CPC H01L 27/1463 (2013.01) [H01L 27/14603 (2013.01); H01L 27/14629 (2013.01); H01L 27/14636 (2013.01); H01L 27/1464 (2013.01); H01L 27/14643 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An image sensor, comprising:
a first structure, a second structure, and a third structure that are sequentially stacked in a vertical direction,
wherein the first structure comprises a first substrate and at least one first transistor disposed on the first substrate,
wherein the second structure comprises a second substrate and at least one second transistor disposed on the second substrate,
wherein the third structure comprises:
a third substrate that includes an upper surface on which light is incident and a lower surface that is opposite to the upper surface;
a photoelectric conversion region disposed in the third substrate;
a transfer gate disposed on the lower surface of the third substrate; and
a reflective structure disposed on the lower surface of the third substrate and on a lower surface and a side surface of the transfer gate,
wherein the reflective structure comprises a first refractive index layer disposed on the lower surface of the third substrate and on the lower surface and the side surface of the transfer gate, and a second refractive index layer disposed on a lower surface of a portion of the first refractive index layer that is on the lower surface of the third substrate, and
wherein the lower surface of the portion of the first refractive index layer on the lower surface of the transfer gate and a lower surface of the second refractive index layer are coplanar.