Image sensor and forming method thereof

Abstract

The invention discloses an image sensor and a forming method thereof. The image sensor comprises a semiconductor substrate; a photodiode for absorbing green light, a photodiode for absorbing blue light, a photodiode for absorbing red light and a vertical charge transfer layer which are arranged in the semiconductor substrate; the photodiode for absorbing the green light, the photodiode for absorbing the red light and the vertical charge transfer layer are spaced apart from each other, and the photodiode for absorbing the blue light is arranged on the photodiode for absorbing the red light andextends to cover the vertical charge transfer layer; the image sensor further comprises a planarization layer arranged on the semiconductor substrate, and a filter layer and a micro lens arranged on the planarization layer, the filter layer includes a green filter, a magenta filter and a blue filter, the photodiode for absorbing the green light corresponds to the lower portion of the green filter,the photodiode for absorbing the red light corresponds to the lower portion of the magenta filter, and the vertical charge transfer layer corresponds to the lower portion of the blue filter. According to the image sensor, crosstalk of light to the vertical charge transfer layer is avoided, and the light transmissive area of the image sensor is increased.

Description

technical field [0001] The invention belongs to the technical field of image sensor manufacturing technology, and in particular relates to an image sensor and a forming method thereof. Background technique [0002] In general, an image sensor is a semiconductor device used to convert an optical image into an electrical signal. Image sensors are classified into charge-coupled device (Charge-Coupled Device, CCD) and complementary metal oxide semiconductor (Complementary Metal Oxide Semiconductor, CMOS) image sensors. [0003] Traditional image sensors use red, green and blue color filters, and there are photodiodes under the corresponding filters that absorb light of the corresponding wavelength. The vertical pixel structure utilizes the correlation between the absorption depth of visible light incident on the semiconductor material and the wavelength, that is, the absorption depth of short-wavelength light is small, and the absorption depth of long-wavelength light is large,...

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Problems solved by technology

[0005] The technical problem to be solved by the technical solution of the present invention is how to reduce the crosstalk of light to the vertical charge transfer layer without wasting the light-transmitting area

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