Photoelectric conversion device and a method for producing photoelectric conversion device

摘要

A producing method of a photoelectric conversion device comprises a photoelectric conversion region where are arranged a plurality of pixels including a photoelectric conversion element, a transfer MOS transistor for transferring an electric charge generated at the photoelectric conversion element to a floating diffusion region and an amplifying MOS transistor of which a gate is connected to the floating diffusion region, and a peripheral circuit region where are located a plurality of peripheral MOS transistors for performing at least one of driving the transfer MOS transistor and processing a signal read from the photoelectric conversion region, the photoelectric conversion region and the peripheral circuit region being arranged on the same semiconductor substrate, characterized in that the producing method comprises steps of forming gate electrodes of the transfer MOS transistor, the amplifying MOS transistor and the peripheral MOS transistor implanting fist conductivity type impurity ions with the gate electrodes as a mask forming an insulating film by covering the photoelectric conversion region and the peripheral circuit region forming a side spacer on a side wall of the gate electrode of the peripheral MOS transistor by protecting the insulating film formed in the photoelectric conversion region with a mask and etching back the insulating film formed in the peripheral circuit region; and forming a source region and a drain region of the peripheral MOS transistor by implanting the first conductivity type impurity ions with the insulating film and the side spacer formed in the photoelectric conversion region as a mask such that impurity concentrations of the source region and the drain region of the peripheral transistor are higher than impurity concentration of the floating diffusion region.