Method for manufacturing image sensor including forming finfet transfer gate having a plurality of channel fins above a p-type region

Abstract

A pixel sensor includes a transfer fin field effect transistor (finFET) to transfer a photocurrent from a photodiode to a drain region. The transfer finFET includes at least a portion of the photodiode, an extension region associated with the drain region, a plurality of channel fins, and a transfer gate at least partially surrounding the channel fins to control the operation of the transfer finFET. In the transfer finFET, the transfer gate is wrapped around (e.g., at least three sides) of each of the channel fins, which provides a greater surface area over which the transfer gate is enabled to control the transfer of electrons. The greater surface area results in greater control over operation of the finFET, which may reduce switching times of the pixel sensor (which enables faster pixel sensor performance) and may reduce leakage current of the pixel sensor relative to a planar transfer transistor.