The present disclosure relates to a photodiode comprising a first part made of silicon and a second part made of doped germanium lying on and in contact with the first part, the first part comprising a stack of a first area and of a second area forming a p-n junction and the doping level of the germanium increasing as the distance from the p-n junction increases.

The present technology relates to a solid-state imaging apparatus and a driving method that can perform imaging at lower power consumption. By providing the solid-state imaging apparatus including a pixel array section on which a plurality of SPAD pixels is two-dimensionally arranged, in which in a case where illuminance becomes first illuminance higher than reference illuminance, a part of the SPAD pixels of the plurality of pixels arranged on the pixel array section is thinned, it is possible to image at lower power consumption. The present technology can be applied to an image sensor, for example.

A structure of the avalanche photodiode type includes a first P doped semiconducting zone, a second multiplication semiconducting zone adapted to supply a multiplication that is preponderant for electrons, a fourth P doped semiconducting “collection” zone. One of the first and second semiconducting zones forms the absorption zone. The structure also includes a third semiconducting zone formed between the second semiconducting zone and the fourth semiconducting zone. The third semiconducting zone has an electric field in operation capable of supplying an acceleration of electrons between the second semiconducting zone and the fourth semiconducting zone without multiplication of carriers by impact ionisation.

Methods and devices for an avalanche photo-transistor. In one aspect, an avalanche photo-transistor includes a detection region configured to absorb light incident on a first surface of the detection region and generate one or more charge carriers in response, a first terminal in electrical contact with the detection region and configured to bias the detection region, an interim doping region, a second terminal in electrical contact with the interim doping region and configured to bias the interim doping region, a multiplication region configured to receive the one or more charge carriers flowing from the interim doping region and generate one or more additional charge carriers in response, a third terminal in electrical contact with the multiplication region and configured to bias the multiplication region, wherein the interim doping region is located in between the detection region and the multiplication region.

Provided is a semiconductor device capable of achieving high detection efficiency and low jitter without depending on an increase in thickness of a substrate. A semiconductor device is provided with a plurality of pixels in each of which an avalanche photodiode element that photoelectrically converts incident light is formed, and each of the plurality of pixels is provided with a substrate including a first semiconductor material, and a stacked portion stacked on a surface on a light incident side of the substrate and including a second semiconductor material different from the first semiconductor material.

The present invention provides a normal-incident photodiode structure with a dark current self-compensation function, including a photosensitive photodiode and a compensating photodiode, where a photosensitive surface of the compensating photodiode is provided with a light-blocking layer, and dark currents of the photosensitive photodiode and the compensating photodiode are equal. According to the present invention, the dark current self-compensation function may be implemented at a chip level without an external circuit and an operational amplifier; the normal-incident photodiode structure according to the present invention has the photosensitive photodiode and the compensating photodiode, and the compensating photodiode may counteract the dark current of the photosensitive photodiode during operation, thus reducing noise caused by the dark current of the photosensitive photodiode; and bias voltages of the photosensitive photodiode and the compensating photodiode according to the present invention are controlled separately, and thus may be applied to more usage scenarios.

Techniques for realizing compound semiconductor (CS) optoelectronic devices on silicon (Si) substrates are disclosed. The integration platform is based on heteroepitaxy of CS materials and device structures on Si by direct heteroepitaxy on planar Si substrates or by selective area heteroepitaxy on dielectric patterned Si substrates. Following deposition of the CS device structures, device fabrication steps can be carried out using Si complimentary metal-oxide semiconductor (CMOS) fabrication techniques to enable large-volume manufacturing. The integration platform can enable manufacturing of optoelectronic module devices including photodetector arrays for image sensors and vertical cavity surface emitting laser arrays. Such module devices can be used in various applications including light detection and ranging (LIDAR) systems for automotive and robotic vehicles as well as mobile devices such as smart phones and tablets, and for other perception applications such as industrial vision, artificial intelligence (AI), augmented reality (AR) and virtual reality (VR).

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 waveguide type photodetector includes a first semiconductor layer of a first conductive type, a multiplication layer of a first conductive type on the first semiconductor layer, an optical waveguide structure, and a photodiode structure. The photodiode structure has a third semiconductor layer of a second conductive type, an optical absorption layer of an intrinsic conductive type or of a second conductive type, and a second semiconductor layer of a second conductive type. The optical waveguide structure includes an optical waveguiding core layer and a cladding layer. An end face of the photodiode structure located in a second region of the first semiconductor layer and an end face of the optical waveguide structure located in a first region of the first semiconductor layer are in contact.

An avalanche photodiode (APD) structure, comprising an absorption layer comprising InGaAs, InGaAlAs, InGaAsP, or an InGaAs/GaAsSb type-II superlattice, an avalanche layer comprising AlGaAsSb, and a transition portion disposed between the absorption layer and the avalanche layer is disclosed. The transition portion comprises a first grading layer of InAlGaAs or InGaAsP and a first field control layer disposed between the first grading layer and the avalanche layer. The first field control layer has a bandgap between the bandgap of the absorption layer and the bandgap of the avalanche layer. In an alternative embodiment, an avalanche photodiode (APD) structure, comprising an absorption layer comprising GaAsSb, an avalanche layer comprising AlGaAsSb, and a transition portion disposed between the absorption layer and the avalanche layer. The transition portion comprises a first grading layer and one or more field control layers having a bandgap between the bandgaps of the absorption layer and the avalanche layer.