A photo detector device is provided. The photo detector device includes a substrate, a first metal layer, a first interlayer dielectric layer, an active layer, a photodiode, and a second metal layer. The first metal layer is disposed on the substrate, wherein the first metal layer includes a gate line and a gate, and the gate is electrically connected to the gate line. The first interlayer dielectric layer is disposed on the first metal layer. The active layer is electrically insulated from the gate and partially overlaps the gate. The photodiode is disposed on the substrate. The second metal layer is disposed on the first interlayer dielectric layer, wherein the second metal layer includes a data line and a bias line, and the bias line is disposed on the photodiode.

A semiconductor device includes: a thin film transistor including an oxide semiconductor layer that is formed in an island shape and contains at least one or more elements among indium, gallium, zinc, and tin and oxygen, a source and a drain that are connected to the oxide semiconductor layer; a protective film of at least one or more layers that is formed in an upper layer of the oxide semiconductor layer, and an opening portion that is disposed in the protective film and has a position and a size for including a channel region or a back channel region of the oxide semiconductor layer; and a photodiode that is disposed in an upper layer upper than the oxide semiconductor layer of the thin film transistor and includes a hydrogenated amorphous silicon layer.

A photodetector includes a germanium layer evanescently coupled to a ring resonator. The ring resonator increases the interaction length between light guided by the ring resonator and the germanium layer without increasing the size of the photodetector, thereby keeping the photodetector's dark current at a low level. The germanium layer absorbs the guided light and converts the absorbed light into electrical signals for detection. The increased interaction length in the resonator allows efficient transfer of light from the resonator to the germanium layer via evanescently coupling. In addition, the internal and external quality factors (Q) of the ring resonator can be matched to achieve (nearly) full absorption of light in the germanium with high quantum efficiency.

According to one embodiment, a detection device includes a substrate, a photoelectric conversion element provided on the substrate and including a semiconductor layer, a transistor provided to correspond to the photoelectric conversion element, a support substrate, and a color filter being a green color filter and supported by the support substrate, wherein the color filter overlaps the photoelectric conversion element.

A photo detector includes a substrate, an exciting layer, a first insulation layer, a second insulation layer and a waveguide. The substrate has a recess. The exciting layer is formed in the recess and having a light incident surface and, a first side and a second side opposite to the first side. The first insulation layer is formed in the substrate and disposed on the first side of the exciting layer. The second insulation layer is formed in the substrate and disposed on the second side of the exciting layer. The waveguide is obliquely connected to the light incident surface of the exciting layer. There is an acute angle included between the light incident surface and an extension direction of the waveguide.

A provided semiconductor device includes a Ge photodiode having proper diode characteristics. A groove is provided on a germanium growth protective film, a p-type silicon layer, and a first insulating film from the top surface of the germanium growth protective film without reaching the major surface of a semiconductor substrate. An i-type germanium layer and an n-type germanium layer are embedded in the groove with a seed layer interposed between the layers and the groove, the seed layer being made of amorphous silicon, polysilicon, or silicon germanium. The i-type germanium layer and the n-type germanium layer do not protrude from the top surface of the germanium growth protective film, thereby forming a flat second insulating film having a substantially even thickness on the n-type germanium layer and the germanium growth protective film.

Techniques for enhancing the absorption of photons in semiconductors with the use of microstructures are described. The microstructures, such as pillars and/or holes, effectively increase the effective absorption length resulting in a greater absorption of the photons. Using microstructures for absorption enhancement for silicon photodiodes and silicon avalanche photodiodes can result in bandwidths in excess of 10 Gb/s at photons with wavelengths of 850 nm, and with quantum efficiencies of approximately 90% or more.

An optical semiconductor element includes: a substrate; and a plurality of cells formed on the substrate, the plurality of cells including a first cell, a second cell, and a third cell. A first electrode electrically connected to a first semiconductor layer of the first cell is arranged on the top surface of the first cell, and a second electrode electrically connected to a second semiconductor layer of the third cell is arranged on the top surface of the second cell. Each of the first electrode and the second electrode has a planned contact region with which solder comes into contact during electrical connection with an external member. When viewed from the thickness direction of the substrate, the area of the second electrode on the top surface of the second cell is smaller than the area of the first electrode on the top surface of the first cell.