A solid-state imaging device having a backside illuminated structure, includes: a pixel region in which pixels each having a photoelectric conversion portion and a plurality of pixel transistors are arranged in a two-dimensional matrix; an element isolation region isolating the pixels which is provided in the pixel region and which includes a semiconductor layer provided in a trench by an epitaxial growth; and a light receiving surface at a rear surface side of a semiconductor substrate which is opposite to a multilayer wiring layer.

An image sensor and a method of manufacturing thereof are provided. The image sensor includes a substrate, a grid structure, and color filters. The substrate includes a pixel separation structure defining pixel regions, and a sub-pixel regions for each pixel region. The grid structure is disposed on the substrate and includes first fence segments provided between the sub-pixel regions, and second fence segments provided between neighboring pixel regions. The grid structure defines openings corresponding respectively to the sub-pixel regions. The color filters are disposed in the openings defined by the grid structure. Each of the color filters has a flat top surface and the flat top surface of each color filter is parallel to a bottom surface thereof.

A depth sensor includes a first pixel including a plurality of first photo transistors each receiving a first photo gate signal, a second pixel including a plurality of second photo transistors each receiving a second photo gate signal, a third pixel including a plurality of third photo transistors each receiving a third photo gate signal, a fourth pixel including a plurality of fourth photo transistors each receiving a fourth photo gate signal, and a photoelectric conversion element shared by first to fourth photo transistors of the plurality of first to fourth photo transistors.

Photosensors may be formed on a front side of a semiconductor substrate. An optical refraction layer having a first refractive index may be formed on a backside of the semiconductor substrate. A grid structure including openings is formed over the optical refraction layer. A masking material layer is formed over the grid structure and the optical refraction layer. The masking material layer may be anisotropically etched using an anisotropic etch process that collaterally etches a material of the optical refraction layer and forms non-planar distal surface portions including random protrusions on physically exposed portions of the optical refraction layer. An optically transparent layer having a second refractive index that is different from the first refractive index may be formed on the non-planar distal surface portions of the optical refraction layer. A refractive interface refracts incident light in random directions, and improves quantum efficiency of the photosensors.

A method for manufacturing a back-illuminated solid-state imaging device includes a first step of preparing a first conduction-type semiconductor layer having a front surface and a back surface, a second step of forming a first asperity region on the front surface of the semiconductor layer by selectively etching the front surface of the semiconductor layer, a third step of forming a second asperity region on the front surface of the semiconductor layer by smoothening asperities of the first asperity region, and a fourth step of forming an insulating layer along the second asperity region and forming a plurality of charge transfer electrodes on the insulating layer.

Disclosed is a SPAD pixel for a backside illuminated image sensor. More particularly, the SPAD pixel may improve sensitivity to long wavelengths by maximizing the depth of a PN junction in an epitaxial layer in the SPAD substrate.

A backside illuminated image sensor, including a semiconductor layer, a first gate structure, and a light sensing device, is provided. The semiconductor layer has a first surface and a second surface opposite to each other. The first gate structure is disposed on the second surface. The light sensing device is located in the semiconductor layer. The light sensing device extends from the first surface to the second surface.

The incidence of incident light transmitted through a photoelectric conversion unit onto a charge holding unit, a pixel in the adjacency, and the like can be blocked in a pixel. An image sensor includes a pixel, a wiring layer, and an incident light attenuation unit. The pixel includes a photoelectric conversion unit that is formed in a semiconductor substrate and performs photoelectric conversion based on incident light, and a pixel circuit that generates an image signal according to a charge generated by the photoelectric conversion. The wiring layer is arranged on a surface of the semiconductor substrate different from a surface onto which the incident light is incident, and transports either the image signal or a signal applied to the pixel circuit. The incident light attenuation unit attenuates the incident light transmitted through the photoelectric conversion unit.

An image sensor includes: a pixel substrate that includes a plurality of pixels each having a photoelectric conversion unit that generates an electric charge through photoelectric conversion executed on light having entered therein and an output unit that generates a signal based upon the electric charge and outputs the signal; and an arithmetic operation substrate that is laminated on the pixel substrate and includes an operation unit that generates a corrected signal by using a reset signal generated after the electric charge in the output unit is reset and a photoelectric conversion signal generated based upon an electric charge generated in the photoelectric conversion unit and executes an arithmetic operation by using corrected signals each generated in correspondence to one of the pixels.

An image sensing device includes a substrate layer in which an array of photoelectric conversion elements is formed, grid structures disposed over the substrate layer to divide space above the substrate into different sensing regions, each grid structure including an air layer, color filters formed to fill bottom portions of spaces between the grid structures, the color filters having a higher refractive index than the air layer, and a lens layer disposed over the grid structures and the color filters such that part of the lens layer fills top portions of the spaces between the grid structures, the lens layer having a higher refractive index than of the color filters.