A low noise and high sensitivity image sensor with imaging and phase-difference detection af in all pixels

Abstract

In this paper, we describe a device structure and optical design for a CMOS image sensor with phase-difference detection photodiodes (PD) for autofocus (AF) function. The individual pixel of this image sensor is composed of two horizontally displaced PDs separated by a PN junction. All the effective pixels function as both the imaging and the phase-difference detection AF (PDAF). We have realized a low dark random noise (1.8e- at 1PD, 2.5e- at 1pixel) and high sensitivity (78Ke-/lx.sec at 1green pixel) image sensor with the imaging and the PDAF functions in all the effective pixels.