A photoelectric conversion device includes a photoelectric conversion region, a readout circuit, and a counting circuit. The photoelectric conversion region is configured to generate a signal charge. The readout circuit is configured to, when reading out a signal that is based on the signal charge generated at the photoelectric conversion region, selectively perform first readout for reading out the signal using avalanche multiplication that is based on the signal charge and second readout for reading out the signal without causing avalanche multiplication to occur with respect to at least a part of the signal charge. The counting circuit is configured to count a number of occurrences of avalanche current which is caused to occur by avalanche multiplication in the first readout.

A light sensitive semiconductor structure comprises: a substrate; a doped upper region of said substrate having a first type of doping; a first implant region located below and being in direct contact with said doped upper region, said first implant region having a second type of doping so that a pn-junction is located between said doped upper region and said first implant region; and a second implant region located below said first implant region and having said second type of doping, and wherein a peak in a doping profile of said second type of doping is located in said second implant region.

A single photon avalanche diode (SPAD) device comprises: a silicon layer; an active region in said silicon layer for detecting incident light; and a blocking structure overlapping said active region for blocking incident light having a wavelength at least in the range of 200 nm to 400 nm, so that light having said wavelength can only be detected by said SPAD device when incident upon a region of said silicon layer outside of said active region.

A light receiving element capable of reducing at least either power consumption or a dead time while reducing an input voltage to a readout circuit is proposed. There is provided a light receiving element (200) including a photon response multiplication part (210) that includes a charge multiplication region capable of multiplying a charge generated in response to incidence of a photon, a first resistor part (211) that is connected at one end to one end of the photon response multiplication part and has a resistance value larger than a resistance value of the photon response multiplication part, a second resistor part (212) that is connected at one end to the other end of the first resistor part, and a readout unit (230) that is connected to the other end of the first resistor part and reads an output from the photon response multiplication part via the first resistor part.

A photoelectric conversion apparatus includes an avalanche diode arranged in a semiconductor layer having a first surface and a second surface facing the first surface. The avalanche diode includes a first semiconductor region of a first conductivity type, which is arranged at a first depth, a second semiconductor region of a second conductivity type, which is arranged at a second depth deeper than the first depth with respect to the second surface, a third semiconductor region provided in contact with an end of the first semiconductor region in a planar view from the second surface, a first wiring portion connected to the first semiconductor region, and a second wiring portion connected to the second semiconductor region. In a planar view from the second surface, at least part of a boundary between an insulating film and the second wiring portion that faces the first wiring portion overlaps the third semiconductor region and does not overlap the first semiconductor region.

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.

An imaging device may include single-photon avalanche diodes (SPADs). To improve the sensitivity and signal-to-noise ratio of the SPADs, light scattering structures may be formed in the semiconductor substrate to increase the path length of incident light through the semiconductor substrate. To mitigate crosstalk, an isolation structure may be formed in a ring around the SPAD. The isolation structure may be a hybrid isolation structure with both a metal filler that absorbs light and a low-index filler that reflects light. The isolation structure may be formed as a single trench or may include a backside deep trench isolation portion and a front side deep trench isolation portion. The isolation structure may also include a color filtering material.

The present technology relates to a light receiving element and a ranging system which achieve improvement of pixel characteristics while allowing variation in a breakdown voltage of an SPAD. The light receiving element includes a pixel array in which a plurality of pixels is arranged in a matrix, and a pixel driving unit configured to control respective pixels of the pixel array to be active pixels or non-active pixels. The pixel includes an SPAD, a transistor connected to the SPAD in series, an inverter configured to output a detection signal indicating incidence of a photon on the SPAD, a first transistor which is switched on or off in accordance with control of the pixels to be the active pixels or the non-active pixels, and a second transistor connected to the first transistor in series. The present technology is applicable to a ranging system that detects a range in a depth direction to a subject, for example.

A light detecting device includes first pixel circuitry including a first avalanche photodiode, and second pixel circuitry including a second avalanche photodiode, a first delay circuit including an input coupled to a cathode of the second avalanche photodiode, a first circuit including a first input coupled to the cathode of the second avalanche photodiode, and a second input coupled to an output of the first delay circuit. The light detecting device includes a control circuit coupled to an output of the first circuit and configured to control a potential of an anode of the first avalanche photodiode based on the output of the first circuit. The control circuit is configured to control a potential of an anode of the second avalanche photodiode based on the output of the first circuit.

A photon avalanche diode includes: first, second, and third diodes formed in a semiconductor body, the second diode being a photodiode; a main cathode terminal connected to the cathode of the first diode; a main anode terminal connected to the anode of the third diode; an auxiliary cathode terminal connected to the cathode of the second and third diodes; and an auxiliary anode terminal connected to the anode of the first and second diodes. The main anode terminal is electrically connected to ground or a reference potential. The main cathode terminal is electrically connected to a voltage which causes a photocarrier multiplication region to form within the semiconductor body. The auxiliary anode terminal is electrically connected to ground or to a read-out circuit. The auxiliary cathode terminal is electrically connected to a constant bias voltage less than a voltage applied to the main cathode terminal.