Abstract: An integrated circuit includes a photodetector that has an epitaxial layer with a first conductivity type located over a substrate. A buried layer of the first conductivity type is located within the epitaxial layer and has a higher carrier concentration than the epitaxial layer. A semiconductor layer located over the buried layer has an opposite second conductivity type and includes a first sublayer over the buried semiconductor layer and a second sublayer between the first sublayer and the buried layer. The first sublayer has a larger lateral dimension than the second sublayer, and has a lower carrier concentration than the second sublayer.

Abstract: A photodetector includes a plurality of channels each having a plurality of SPAD units, each SPAD unit having an avalanche photodiode. The photodetector is capable of selecting outputting or non-outputting of the channels. The SPAD unit includes: an active quenching circuit which performs active quenching of the avalanche photodiode; and a control circuit which brings the active quenching circuit which corresponds to the channel where non-outputting is selected into an operable state.

Abstract: An avalanche photo-diode (APD) circuit includes a first APD and a bias circuit. The first APD is configured to detect light. The bias circuit is configured to control a gain of the first APD. The bias circuit includes a second APD, a reference voltage source, a bias voltage generation circuit, and a metal layer configured to shield the second APD from the light. The reference voltage source is configured to bias the second APD. The bias voltage generation circuit is configured to generate a bias voltage for biasing the first APD based on dark current output by the second APD.

Abstract: A semiconductor device that may include an avalanche photodiode (APD), the APD may include: a first doped region of a first polarity; a buried guard ring of a second polarity, the second polarity is opposite to the first polarity, the buried guard ring is spaced apart from the first doped region and is positioned below the first doped region; a well of the second polarity, wherein the well interfaces the first doped region to form a p-n junction; and a second doped region of the second polarity, the second doped region is spaced apart from the first doped region.

Abstract: The invention is directed to an avalanche photodiode containing a substrate and semiconductor layers with various electro-physical properties having common interfaces both between themselves and with the substrate. The avalanche photodiode may be characterized by the presence in the device of at least one matrix consisting of separate solid-state areas with enhanced conductivity surrounded by semiconductor material with the same type of conductivity. The solid-state areas are located between two additional semiconductor layers, which have higher conductivity in comparison to the semiconductor layers with which they have common interfaces. The solid-state areas are generally made of the same material as the semiconductor layers surrounding them but with conductivity type that is opposite with respect to them. The solid-state areas may be made of a semiconductor with a narrow forbidden zone with respect to the semiconductor layers with which they have common interfaces.

Abstract: An avalanche photodiode including a first electrode; and a substrate including a first semiconductor layer of a first conduction type electrically connected to the first electrode, in which at least an avalanche multiplication layer, a light absorption layer, and a second semiconductor layer of a second conduction type with a larger band gap than the light absorption layer are deposited on the substrate. The second semiconductor layer is separated into inner and outer regions by a groove formed therein, the inner region electrically connected to a second. With the configuration, the avalanche photodiode has a low dark current and high long-term reliability. In addition, the outer region includes an outer trench, and at least the light absorption layer is removed by the outer trench to form a side face of the light absorption layer. With the configuration, the dark current can be further reduced.

Abstract: A photodiode array 1 has a plurality of photodetector channels 10 which are formed on an n-type substrate 2 having an n-type semiconductor layer 12, with a light to be detected being incident to the plurality of photodetector channels 10. The photodiode array 1 comprises: a p?-type semiconductor layer 13 formed on the n-type semiconductor layer 12 of the substrate 2; resistors 4 each of which is provided to each of the photodetector channels 10 and is connected to a signal conductor 3 at one end thereof; and an n-type separating part 20 formed between the plurality of photodetector channels 10. The p?-type semiconductor layer 13 forms a pn junction at the interface between the substrate 2, and comprises a plurality of multiplication regions AM for avalanche multiplication of carriers produced by the incidence of the light to be detected so that each of the multiplication regions corresponds to each of the photodetector channels.

Abstract: An embodiment of an array of Geiger-mode avalanche photodiodes, wherein each photodiode is formed by a body of semiconductor material, having a first conductivity type, housing a first cathode region, of the second conductivity type, and facing a surface of the body, an anode region, having the first conductivity type and a higher doping level than the body, extending inside the body, and facing the surface laterally to the first cathode region and at a distance therefrom, and an insulation region extending through the body and insulating an active area from the rest of the body, the active area housing the first cathode region and the anode region. The insulation region is formed by a mirror region of metal material, a channel-stopper region having the second conductivity type, surrounding the mirror region, and a coating region, of dielectric material, arranged between the mirror region and the channel-stopper region.

Abstract: An embodiment of an array of Geiger-mode avalanche photodiodes, wherein each photodiode is formed by a body of semiconductor material, having a first conductivity type, housing a first cathode region, of the second conductivity type, and facing a surface of the body, an anode region, having the first conductivity type and a higher doping level than the body, extending inside the body, and facing the surface laterally to the first cathode region and at a distance therefrom, and an insulation region extending through the body and insulating an active area from the rest of the body, the active area housing the first cathode region and the anode region. The insulation region is formed by a mirror region of metal material, a channel-stopper region having the second conductivity type, surrounding the mirror region, and a coating region, of dielectric material, arranged between the mirror region and the channel-stopper region.

Abstract: An avalanche photodiode structure, to a method of fabricating an avalanche photodiode structure, and to devices incorporating an avalanche photodiode structure. The avalanche photodiode structure comprises a Ge doped region having a first polarity; a GaAs doped region having a second polarity opposite to the first polarity; and an undoped region between the Ge doped region and the GaAs doped region forming a heterojunction; wherein the undoped region comprises Ge and AlxGa1-xAs.

Abstract: A photodiode array 1 has a plurality of photodetector channels 10 which are formed on an n-type substrate 2 having an n-type semiconductor layer 12, with a light to be detected being incident to the plurality of photodetector channels 10. The photodiode array 1 comprises: a p?-type semiconductor layer 13 formed on the n-type semiconductor layer 12 of the substrate 2; resistors 4 each of which is provided to each of the photodetector channels 10 and is connected to a signal conductor 3 at one end thereof; and an n-type separating part 20 formed between the plurality of photodetector channels 10. The p?-type semiconductor layer 13 forms a pn junction at the interface between the substrate 2, and comprises a plurality of multiplication regions AM for avalanche multiplication of carriers produced by the incidence of the light to be detected so that each of the multiplication regions corresponds to each of the photodetector channels.

Abstract: An optical semiconductor device includes a distributed Bragg reflection layer of a first conductivity type, a distortion elaxation layer of the first conductivity type, a light absorbing layer, and a semiconductor layer of a second conductivity type, sequentially arranged on a semiconductor substrate. The distortion relaxation layer the same material as the semiconductor substrate. The total optical length of layers between the distributed Bragg reflection layer and the light absorbing layer is an integer multiple of one-half the wavelength of incident light that is detected.

Abstract: An imaging device is provided and includes: a photoelectric conversion layer that has a silicon crystal structure and generates signal charges upon incidence of light; a multiplication and accumulation layer that multiplies the signal charges by a phenomenon of avalanche electron multiplication; and a wiring substrate that reads the signal charges from the multiplication and accumulation layer and transmits the read signal charges.

Abstract: An avalanche photodiode semiconductor device (20) for converting an impinging photon (22) includes a base n+ doped material layer (52) formed having a window section (72) for passing the photon (22). An n? doped material layer (30) is formed on the n+ doped material layer (52) having a portion of a lower surface (74) suitably exposed. An n+ doped material layer (32) is formed on the n? doped material (30). A p+ layer (24) formed on top of the n+ doped layer (32). At least one guard ring (26) is formed in the n? doped layer (30).

Abstract: A transmitted light absorption/recombination layer, a barrier layer, a wavelength selection/absorption layer, and an InP window layer having a p-type region are supported by an n-type substrate and arranged in that order. Light with a wavelength of 1.3 ?m reaches the wavelength selection/absorption layer through the InP window layer. Then, the light is absorbed by the wavelength selection/absorption layer and drawn from the device as an electric current signal. Light with a wavelength of 1.55 ?m reaches the transmitted light absorption/recombination layer through the barrier layer. Then, the light is absorbed by the transmitted light absorption/recombination layer, generating electrons and holes. These electrons and holes recombine with each other and, hence, disappear.

Abstract: A single-photon avalanche detector is disclosed that is operable at wavelengths greater than 1000 nm and at operating speeds greater than 10 MHz. The single-photon avalanche detector comprises a thin-film resistor and avalanche photodiode that are monolithically integrated such that little or no additional capacitance is associated with the addition of the resistor.

Abstract: An embodiment of an array of Geiger-mode avalanche photodiodes, wherein each photodiode is formed by a body of semiconductor material, having a first conductivity type, housing a first cathode region, of the second conductivity type, and facing a surface of the body, an anode region, having the first conductivity type and a higher doping level than the body, extending inside the body, and facing the surface laterally to the first cathode region and at a distance therefrom, and an insulation region extending through the body and insulating an active area from the rest of the body, the active area housing the first cathode region and the anode region. The insulation region is formed by a mirror region of metal material, a channel-stopper region having the second conductivity type, surrounding the mirror region, and a coating region, of dielectric material, arranged between the mirror region and the channel-stopper region.

Abstract: An embodiment of array of Geiger-mode avalanche photodiodes, wherein each photodiode is formed by a body of semiconductor material, having a first conductivity type and housing an anode region, of a second conductivity type, facing a top surface of the body, a cathode-contact region, having the first conductivity type and a higher doping level than the body, facing a bottom surface of the body, an insulation region extending through the body and insulating an active area from the rest of the body, the active area housing the anode region and the cathode-contact region. The insulation region is formed by a first mirror region of polycrystalline silicon, a second mirror region of metal material, and a channel-stopper region of dielectric material, surrounding the first and second mirror regions.

Abstract: In a semiconductor photo-detecting element (an avalanche photodiode), a high-sensitivity element is obtained by incorporating a multiplication layer having high-performance multiplication characteristics. By using a structure which reduces an electric field applied to an etching stopper layer, it is possible to use a multiplication layer having higher-performance multiplication characteristics (a multiplication layer which performs multiplication with a high electric field). The first method to realize this is to use a conductivity type multiplication layer. The second method is to use a structure in which a field buffer layer of the second conductivity type is incorporated. As a result of the use of these methods, a structure which applies an electric field lower than the multiplier electrical field to the etching stopper layer is obtained.

Abstract: An avalanche photodiode (APD) includes an anode layer, a cathode layer, an absorption layer between the anode layer and the cathode layer, a first multiplying stage between the absorption layer and the cathode layer, a second multiplying stage between the first multiplying stage and the cathode layer, and a carrier relaxation region between the first and second multiplying stages. Each multiplying stage includes, in the direction of drift of electrons, a first layer that is doped with acceptors, a second layer that is substantially undoped, a third layer that is doped with acceptors, a fourth layer that is substantially undoped, and a fifth layer that is doped with donors.

Abstract: A semiconductor light-receiving device includes: a semi-insulating substrate; a semiconductor layer of a first conduction type that is formed on the semi-insulating substrate; a buffer layer of the first conduction type that is formed on the semi-insulating substrate and has a lower impurity concentration than the semiconductor layer of the first conduction type; a light absorption layer that is formed on the buffer layer and generates carriers in accordance with incident light; a semiconductor layer of a second conduction type that is formed on the light absorption layer; and a semiconductor intermediate layer that is interposed between the buffer layer and the light absorption layer, and has a forbidden bandwidth within a range lying between the forbidden bandwidth of the buffer layer and the forbidden bandwidth of the light absorption layer.

Abstract: In a semiconductor photo-detecting element (an avalanche photodiode), a high-sensitivity element is obtained by incorporating a multiplication layer having high-performance multiplication characteristics. By using a structure which reduces an electric field applied to an etching stopper layer, it is possible to use a multiplication layer having higher-performance multiplication characteristics (a multiplication layer which performs multiplication with a high electric field). The first method to realize this is to use a conductivity type multiplication layer. The second method is to use a structure in which a field buffer layer of the second conductivity type is incorporated. As a result of the use of these methods, a structure which applies an electric field lower than the multiplier electrical field to the etching stopper layer is obtained.