Patent ID: 7605415

Claim:
An amplifying type image pickup device, comprising a plurality of pixels, wherein each pixel includes: a photoelectric conversion unit for converting incident light into a signal carrier; a floating diffusion portion, arranged adjacent to the photoelectric conversion unit so as to sandwich a portion of a transfer transistor between the floating diffusion portion and the photoelectric conversion unit, for converting the signal carrier generated by the photoelectric conversion unit into a signal voltage; an amplification transistor, having a gate connected to the floating diffusion portion, for outputting an amplified signal based on the signal voltage; a well of a second conductivity type arranged on a semiconductor substrate of a first conductivity type; a first semiconductor region of the first conductivity type, capable of accumulating the signal carrier, arranged in the well of the second conductivity type and constituting a part of the photoelectric conversion unit; a second semiconductor region of the first conductivity type, arranged in the well of the second conductivity type, operating as a source region or a drain region of the amplification transistor; an element isolation region arranged between the first and second semiconductor regions; and a guard region portion of the second conductivity type arranged under the element isolation region, the guard region portion including a plurality of semiconductor regions of the second conductivity type respectively at different depths, having an impurity concentration higher than that of the well of the second conductivity type, and extending to reach the semiconductor substrate, wherein the guard region portion of the second conductivity type surrounds the first semiconductor region and the floating diffusion portion of the pixel, and the second semiconductor region is sandwiched between a guard region included in a first pixel and a guard region included in a second pixel adjacent to the first pixel, so that the well remains under the second semiconductor region.