BACKGROUND

1. Field

One or more embodiments described herein relate to an image sensor and a method for manufacturing an image sensor.

2. Description of the Related Art

An image sensor converts an optical image into an electrical signal. As the computer and communication industries continue to develop, the demand for image sensors with improved performance increases in various fields, including but not limited to digital cameras, camcorders, personal communication systems, game devices, security cameras, medical micro-cameras, and robotics,

An image sensor generally includes a pixel array, where each pixel has a photo diode that performs a photoelectric conversion function. Each pixel may also have a color filter to filter light of a specific wavelength region. In these and other types of image sensors, optical crosstalk may occur, for example, based on a spectral difference between adjacent pixels.

SUMMARY

In accordance with one or more embodiment, an image sensor includes a semiconductor substrate; a plurality of photoelectric detectors; a plurality of color filters spaced from the semiconductor substrate; and at least one pixel isolation region having a predetermined depth, wherein the at least one pixel isolation region is between adjacent ones of the photoelectric detectors, wherein the color filters include a white color filter, and wherein the color filters correspond to respective ones of the photoelectric detectors.

The color filters may include one of a green filter, a red filter, or a blue filter. The at least one pixel isolation region may extend between the semiconductor substrate a layer including the color filters, and the at least one pixel isolation region may contact the semiconductor substrate. The at least one pixel isolation region may include an insulating material. The at least one pixel isolation region may include a bottom at a higher level than a bottom of at least one of the photoelectric detectors.

In accordance with another embodiment, an image sensor includes a semiconductor substrate; at least one pixel isolation region in a trench over the semiconductor substrate; a plurality of photoelectric detectors separated from each other by the at least one pixel isolation region; an antireflection layer on the at least one pixel isolation region and the photoelectric detectors; a plurality of color filters on the anti-reflection layer; and a plurality of microlenses on the color filters, wherein the color filters include a white filter.

The at least one pixel isolation region may be between the semiconductor substrate and a layer including the color filters, and the at least one pixel isolation region may contact the semiconductor substrate. The at least one pixel isolation region may include silicon oxide. The at least one pixel isolation region may include an oxide of a high permittivity.

The at least one pixel isolation layer may include an insulating layer surrounding a conductive metal layer. The at least one pixel isolation region may extend in a direction toward the semiconductor substrate, and a bottom of the at least one pixel isolation region may be at a higher level than a bottom of one or more of the photoelectric detectors. A refractive index of the at least one pixel isolation region may be different from a refractive index of one or more of the photoelectric detectors. The color filters may include a green filter, a red filter, or a blue filter. The color filters may correspond to the photoelectric detectors, respectively. The microlenses may correspond to the color filters, respectively.

In accordance with another embodiment, a method of manufacturing an image sensor includes providing a semiconductor substrate; forming a photoelectric detector layer on the semiconductor substrate; limning at least one trench in the photoelectric detector layer to a predetermined depth; filling the at least one trench with an insulating material to form at least one isolation region; forming a color filter layer on the photoelectric detector layer and the at least one isolation region, the color filter layer including a white filter and at least one of a red filter, a green filter, or a blue filter; and forming microlenses on the color filter layer.

Forming the at least one trench may include etching the photoelectric detector layer in a direction of the semiconductor substrate. Forming the at least one trench may include etching the photoelectric detector layer so that a height of the at least one trench is substantially equal to a height of the photoelectric detector layer and so that a surface of the semiconductor substrate is exposed. Forming the at least one trench may include etching the photoelectric detector layer so that a bottom of the at least one trench is higher than a bottom of the photoelectric detector layer. The at least one trench may be between adjacent photoelectric detectors in the photoelectric detector layer. The insulating material may have a refractive index different from a refractive index of the photoelectric detector layer.

The method may include forming an anti-reflection layer before forming the color filter layer. The method may include forming a polysilicon layer inside the at least one trench. Use microlenses may correspond to the white filter and at least one of the red filter, the green filter, or the blue filter, respectively. The white filter and at least one of the red filter, green filter, and blue filter may correspond to the photoelectric detectors, respectively.

In accordance with another embodiment, an image sensor includes a first pixel; a second pixel; and an isolation region between the first and second pixels, wherein each of the first and second pixels includes a photodetector and a color filter, the isolation region under the color filter and extending along and optically separating the photodetectors of the first and second pixels. The isolation region may include a first surface to reflect incident light in a direction toward the photodetector of the first pixel and a second surface to reflect incident light in a direction toward the photodetector of the second pixel.

The image sensor may include a first color filter and a second color filter, wherein the first color filter may correspond to the photodetector of the first pixel and the second color filter may correspond to the photodetector of the second pixel, and wherein the first color filter may be a white color filter. The isolation region and the photodetectors of the first and second pixels may have substantially a same height. The isolation region may have a first length, the photodetectors of the first and second pixels may have a second length, and the first length may be less than the second length.

