Image sensor and manufacturing method of image sensor

Abstract

The invention relates to an image sensor and a manufacturing method of the image sensor. The image sensor comprises a photodiode, a first conducting type isolation layer, a second conducting type shallow doping region, a first conducting type shallow doping region, a transmission tube grid electrode structure and a floating diffusion region, wherein the second conducting type shallow doping region is formed inside a first conducting type semiconductor substrate, the first conducting type shallow doping region is formed at the lower part of the second conducting type shallow doping region, the second conducting type shallow doping region is isolated in a second conducting type region of the photodiode through the first conducting type shallow doping region, and the floating diffusion region is provided with the second conducting type heavy doping. The image sensor has the advantages that through the formation of the second conducting type shallow doping region in contact with the floating diffusion region, the distance between the floating diffusion region and the photodiode is reduced, so photon-generated carriers can be more rapidly transmitted to the floating diffusion region from the photodiode, and the transmission efficiency of the photon-generated carriers is improved.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to an image sensor and a manufacturing method thereof. Background technique [0002] Image sensors are semiconductor devices that convert optical signals into electrical signals. The image sensor includes a photodiode (photo diode, PD) for sensing light and a logic circuit for converting the sensed light into an electrical signal. The logic circuit generally includes a transfer transistor, and the photodiode is connected to a floating diffusion region (Floating Diffusion, FD) through the transfer transistor. When the image sensor is working, the photo-generated carriers in the photodiode are transferred to the floating diffusion region through the channel of the transfer pipe by opening the transfer pipe. [0003] In existing image sensors, the transfer efficiency of photogenerated carriers from photodiodes to floating diffusion regions is low. For more information on the ...

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Problems solved by technology

[0003] In existing image sensors, the transfer efficiency of photogenerated carriers from the photodiode to the floating diffusion region is low

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