Patent ID: 8378400
Filing Date: 2013-02-19
Classification: H01L,Y02E

Abstract:
1. A solid-state imaging device in which a plurality of pixels are two-dimensionally arranged, a plurality of island-shaped semiconductors constituting the plurality of pixels being formed on a substrate, wherein: the plurality of island-shaped semiconductors each comprises a first semiconductor region formed in a lower area of the island-shaped semiconductor, a second semiconductor region formed on the first semiconductor region and having a conductivity type opposite to a conductivity type of the first semiconductor region or being an intrinsic semiconductor, a third semiconductor region formed on an upper lateral side of the second semiconductor region and having a conductivity type the same as the conductivity type of the first semiconductor region, a fourth semiconductor region formed on an outer periphery of the third semiconductor region and having a conductivity type opposite to the conductivity type of the first semiconductor region, an insulating layer formed on an outer periphery of the fourth semiconductor region and a lower lateral side of the second semiconductor region, a conductive layer formed on an outer periphery of the insulating layer and functioning as a gate electrode forming a channel in a lower area of the second semiconductor region, a reflection conductive layer formed on an outer periphery of the third semiconductor region, the fourth semiconductor region, and the insulating layer and reflecting an electromagnetic energy wave, a fifth semiconductor region formed over the second semiconductor region and the third semiconductor region and having a conductivity type the same as the conductivity type of the fourth semiconductor region, and a microlens formed over the fifth semiconductor region and whose focal point is located in a portion near an upper surface of the fifth semiconductor region; the island-shaped semiconductor includes a portion functioning as a photoelectric conversion unit, a portion functioning as a signal charge storing unit, a portion functioning as a signal charge reading unit, and a portion functioning as a stored signal charge discharging unit; the photoelectric conversion unit includes a photodiode region including the second semiconductor region and the third semiconductor region and an electromagnetic energy wave incident to the microlens generates signal charges in the photoelectric conversion unit; the signal charge storing unit includes the third semiconductor region and stores the signal charges generated in the photoelectric conversion unit; the signal charge reading unit includes a junction transistor in which each of the fifth semiconductor region and a lower area of the second semiconductor region serves as a drain or a source and the signal charge storing unit serves as a gate, and functions to read as an output signal a drain-source current which flows between the drain and the source of the junction transistor and changes in accordance with the amount of signal charges stored in the signal charge storing unit; and the stored signal charge discharging unit includes a MOS transistor in which the first semiconductor region serves as a drain, the conductive layer serves as a gate, the third semiconductor region serves as a source, and a portion of the second semiconductor region that is sandwiched between the first semiconductor region and the third semiconductor region serves as a channel, and functions to apply a certain voltage to the conductive layer to discharge the signal charges stored in the signal charge storing unit to the first semiconductor region.