Light detection device

A photodetection device comprising:

• a semiconductor photodetection element including a semiconductor substrate having a first surface, and a second surface opposite to the first surface and on which detection target light is incident, and including a photodetection region on the first surface configured to generate a charge in an amount according to a light intensity of the detection target light, and a light absorption film provided on a region of at least a part of a region around a region obtained by projecting the photodetection region on the second surface in a direction opposite to an incident direction of the detection target light;
• and
• a package having an optical window through which the detection target light passes, and configured to contain the semiconductor photodetection element, wherein
• the light absorption film has a multi-layer structure including a light absorption layer, a resonance layer provided between the light absorption layer and the semiconductor substrate, and a reflection layer being a metal layer provided between the resonance layer and the semiconductor substrate, and
• at a wavelength of the detection target light, a light transmittance inside the resonance layer is larger than a light transmittance inside the light absorption layer, and a light reflectance on a surface of the reflection layer is larger than a light reflectance on a surface of the resonance layer, and wherein
• the light absorption layer mainly contains tungsten silicide.

A photodetection device comprising:

• a semiconductor photodetection element including a semiconductor substrate having a first surface on which detection target light is incident, and a second surface opposite to the first surface, and including a photodetection region on the first surface side configured to generate a charge in an amount according to a light intensity of the detection target light, and a light absorption film provided on a region of at least a part of a region around the photodetection region on the first surface;
• and
• a package having an optical window through which the detection target light passes, and configured to contain the semiconductor photodetection element, wherein
• the light absorption film has a multi-layer structure including a light absorption layer, a resonance layer provided between the light absorption layer and the semiconductor substrate, and a reflection layer being a metal layer provided between the resonance layer and the semiconductor substrate, and
• at a wavelength of the detection target light, a light transmittance inside the resonance layer is larger than a light transmittance inside the light absorption layer, and a light reflectance on a surface of the reflection layer is larger than a light reflectance on a surface of the resonance layer, and wherein
• the semiconductor photodetection element further includes an electrode pad for wire bonding electrically connected to the photodetection region on the first surface, and
• the light absorption film is configured to cover at least a part of the electrode pad.