Phase focusing image sensor and forming method thereof

Abstract

The invention discloses a phase focusing image sensor and a forming method thereof. According to the method, a semiconductor substrate, a first photosensitive structure and a first filter layer are provided, wherein the semiconductor substrate comprises a phase focusing area and has a first surface and a second surface opposite to the first surface; the first photosensitive structure is located inthe phase focusing area of the semiconductor substrate; the first photosensitive structure comprises a first surface and a second surface opposite to the first surface; the first photosensitive structure comprises an absorption layer which is used for absorbing near infrared light; the first surface of the first photosensitive layer is exposed from the absorption layer; the first filter layer islocated on the second surface of the phase focusing area of the semiconductor substrate; and natural light passes through the first filter layer. The performance of the phase focusing image sensor isimproved.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a phase focus image sensor and a forming method thereof. Background technique [0002] An image sensor is a semiconductor device that converts light signals into electrical signals. At present, CMOS phase focusing image sensors have been widely used in digital still cameras, digital video cameras, medical imaging devices, and automotive imaging devices. [0003] At present, the focus methods used in mobile phone shooting are mainly contrast detection autofocus (contrast detection autofocus) and phase detect autofocus (PDAF for short). The principle of contrast focusing is to find the position of the lens with the maximum contrast according to the contrast change of the picture at the focal point, that is, the position of accurate focus. The principle of phase focusing is to reserve some pixels on the photosensitive element for phase detection, and determine the focus ...

AI Technical Summary

Problems solved by technology

[0004] However, since phase focusing needs to use pixels for phase detection, phase focusing has relatively high requirements on light intensity, and the focusing speed and accuracy are not high in dark and weak light environments, resulting in poor performance of phase focusing image sensors.

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