A sensor chip includes a sensor pixel. The sensor pixel includes an avalanche photodetector. A circuit is adjacent to the avalanche photodetector. The circuit is coupled to the avalanche photodetector. An isolation structure at least partially encloses the circuit and is between the avalanche photodetector and the circuit.

Provided is a semiconductor device capable of improving the optical response speed. The semiconductor device includes a pixel array portion in which a plurality of pixels are arranged in a matrix, each of the plurality of pixels including: a pixel forming region partitioned by a separation region in a semiconductor layer; a first semiconductor region of a first conductivity type and a second semiconductor region of a second conductivity type sequentially arranged from a first surface side of the pixel forming region toward a second surface side opposite to the first surface; a pn junction portion in which the first semiconductor region and the second semiconductor region are bonded; a charge extraction region of the second conductivity type provided in a side wall of the separation region; and a relay region of the second conductivity type provided at a position deeper than the second semiconductor region so as to be connected to the charge extraction region and the second semiconductor region. A plurality of the pn junction portions are scattered apart from each other, and the relay region has a higher impurity concentration than the second semiconductor region and terminates at a peripheral portion so as to surround a central portion of a surface of the second semiconductor region opposite to the pn junction portion side.

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.

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.

There is provided a photodetection circuit capable of improving distance measuring performance.

The photodetection circuit according to an embodiment of the present disclosure includes: an avalanche photodiode; a charging circuit that supplies a voltage to the avalanche photodiode; an input amplifier including a comparison circuit in which a voltage level of an output terminal changes according to a comparison result between a voltage of an input terminal connected to the avalanche photodiode and a reference voltage, and a voltage control circuit that changes a potential of the reference voltage; and a state detecting circuit that sets timing for causing the voltage control circuit to change the potential of the reference voltage on the basis of a detection result of the voltage level.

An optical sensing device includes a light source, which emits one or more beams of light pulses toward a target scene at respective angles about a transmit axis of the light source. A first array of single-photon detectors output electrical pulses in response to photons that are incident thereon. A second array of counters count the electrical pulses output during respective count periods by respective sets of one or more of the single-photon detectors. Light collection optics form an image of the target scene on the first array along a receive axis, which is offset transversely relative to the transmit axis, thereby giving rise to a parallax shift as a function of distance between the target scene and the device. Control circuitry sets the respective count periods of the counters, responsively to the parallax shift, to cover different, respective time intervals following each of the light pulses.

An image pickup element using an APD is provided. The image pickup element has a first substrate, a second substrate, and a connector. The first substrate is provided with a plurality of light receivers having the APD. The second substrate has a pixel circuit that corresponds to each of the APDs. Additionally, the connector electrically connects the APD and the pixel circuit corresponding to the APD.

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.

A photoelectric conversion device includes a pixel, the pixel including an avalanche photodiode, and a signal processing circuit including a counter configured to generate a count value based on a photon incident on the avalanche photodiode during a count period, the signal processing circuit being configured to output the count value for each count period repeatedly. The pixel transitions from a first state to a second state in which a length of the count period is shorter than that in the first state in accordance with a result of determination based on the count value and a predetermined threshold value.