Solid-state imaging device and endoscope system

A backside illumination type solid-state imaging device, comprising:

• a semiconductor layer having a first surface, a second surface, and a plurality of photoelectric conversion elements;
• an electrode disposed on the first surface;
• a wiring layer laminated on the second surface of the semiconductor layer;
• a plurality of filters arranged on the first surface side at positions corresponding to the plurality of photoelectric conversion elements;
• an input terminal to which a reference voltage is input from outside;
• and
• a voltage generation circuit configured to generate a first voltage and a second voltage on the basis of the reference voltage input to the input terminal,
• wherein the plurality of filters include a first filter and a second filter,
• a light transmittance of the first filter has a peak in a wavelength range corresponding to blue,
• a light transmittance of the second filter has a peak at a wavelength of 450 nm or more, and in the second filter, a transmittance of light having a wavelength of 450 nm or less is greater than a minimum value of a transmittance of light having a wavelength longer than 450 nm,
• the first voltage and the second voltage are selectively applied to the electrode,
• the second voltage differs from the first voltage,
• the voltage generation circuit is configured to generate the second voltage to cause the photoelectric conversion elements to have a higher sensitivity to light having a wavelength of 450 nm or less, compared to when the first voltage is applied to the electrode,
• a potential in a cross section of the semiconductor layer has a first distribution when the first voltage is applied to the electrode,
• the potential in the cross section of the semiconductor layer has a second distribution when the second voltage is applied to the electrode,
• in a first region of the cross section of the semiconductor layer, the potential at a peak of the first distribution is greater than the potential at a peak of the second distribution, the first region is a region in which a distance from the first surface is less than 0.3 μm,
• a material constituting the semiconductor layer includes silicon,
• in the first distribution, a gradient of a variation of the potential in a second region of the cross section of the semiconductor layer is greater than a gradient of a variation of the potential in a third region,
• the second region is a region in which the distance is greater than a first distance at the peak of the first distribution and is less than 0.3 μm, and
• the third region is a region between the first surface and the photoelectric conversion elements in which the distance is 0.3 μm or more.