Photodiode array for image pickup device

A photodiode array comprising:

• a substrate of a common read-out control circuit;
• and
• a plurality of photodiodes arrayed on the substrate and each including an absorption layer, and a pair of a first conductive-side electrode and a second conductive-side electrode,
• wherein each of the photodiodes is separated from adjacent photodiodes,
• the first conductive-side electrodes are provided on first conductivity-type regions and electrically connected in common across all the photodiodes,
• the second conductive-side electrodes are provided on second conductivity-type regions and individually electrically connected to read-out electrodes of the read-out control circuit,
• the photodiodes are semiconductor multilayer structures formed on a semiconductor substrate,
• the semiconductor substrate has been removed or the semiconductor substrate is included in the semiconductor multilayer structure,
• each of the second conductivity-type regions is formed by selective diffusion for corresponding photodiode so as to face the absorption layer,
• the second conductive-side electrodes are provided on the corresponding second conductivity-type regions,
• the second conductive-side electrodes are connected to the corresponding read-out electrodes on the substrate of the read-out control circuit, and
• a surface of the semiconductor multilayer structures opposite a surface on which the second conductive-side electrodes are disposed functions as a light-incident surface.