VERTICAL TRANSFER GATE STRUCTURE FOR A BACK-SIDE ILLUMINATION (BSI) COMPLEMENTARY METAL-OXIDE-SEMICONDUCTOR (CMOS) IMAGE SENSOR USING GLOBAL SHUTTER CAPTURE

摘要

A back-side illumination (BSI) complementary metal-oxide-semiconductor (CMOS) image sensor using a vertical transfer gate structure for improved quantum efficiency (QE) and global shutter efficiency (GSE) is provided. A semiconductor column extends vertically from a photodetector, towards a back-end-of-line (BEOL) stack. A floating diffusion region (FDR) is vertically spaced from the photodetector by the semiconductor column. The FDR comprises a sidewall surface laterally offset from a neighboring sidewall surface of the semiconductor column to define a lateral recess between the FDR and the photodetector. A gate dielectric layer lines the sidewall surface of the semiconductor column and is arranged in the lateral recess. A gate is arranged laterally adjacent to the gate dielectric layer and filling the lateral recess. Further, a method for manufacturing the vertical transfer gate structure is provided.

主权项

1. A back side illumination (BSI) image sensor comprising:
a semiconductor column extending vertically from a photodetector, towards a back-end-of-line (BEOL) stack; a floating diffusion region (FDR) vertically spaced from the photodetector by the semiconductor column, wherein the FDR comprises a sidewall surface laterally offset from a neighboring sidewall surface of the semiconductor column to define a lateral recess between the FDR and the photodetector; a gate dielectric layer lining the sidewall surface of the semiconductor column and arranged in the lateral recess; and a gate arranged laterally adjacent to the gate dielectric layer and filling the lateral recess.