Solid-state image pickup device

Abstract

Abstract PURPOSE:To remove surely an excess charge without requiring an extra area, by forming a clip diode on a semiconductor substrate of a unit picture element by lamination. CONSTITUTION:A diffusion layer 1 is a junction diode part which has a conductive type opposite to that of a semiconductor substrate 2 and is connected electrically to a photoconductor film 5 through a conductive electrode 3 and a metallic electrode 4. A conductive electrode 6 having a conductive type opposite to that of the electrode 3 forms a junction diode 7 which is operated as a clip diode between electrodes 6 and 3, and an optional voltage is biased from the external. The potential of the diode 1 rises in accordance with the strength of a signal light. However, if the clip potential of the storage diode 1 is set to a value equal to the transfer capacity of a CCD of a transfer line 9 at this time, all of the excess signal charge larger than the transfer capacity is swept away to the diode 7 side. When the clip potential of the diode 1 is selected properly, the signal charge is prevented from overflowing to the transfer line even if a strong light is incident.

Inventors

• 👤 Mitsuo Nakayama
• 👤 光雄 中山

Bibliographic Details