A non-diffusion type photodiode is described and has: a substrate, a buffer layer, a light absorption layer, an intermediate layer, and a multiplication/window layer. The buffer layer is disposed on the substrate. The light absorption layer is disposed on the buffer layer. The intermediate layer is disposed on the light absorption layer and has a first boundary, wherein the intermediate layer is an I-type semiconductor layer or a graded refractive index layer. The multiplication/window layer is disposed on the intermediate layer and has a second boundary, wherein in a top view, the first boundary surrounds the second boundary, and a distance between the first boundary and the second boundary is greater than or equal to 1 micrometer. The non-diffusion type photodiode can reduce generation of dark current.

A non-diffusion type photodiode is described and has: a substrate, a buffer layer, a light absorption layer, an intermediate layer, and a multiplication/window layer. The buffer layer is disposed on the substrate. The light absorption layer is disposed on the buffer layer. The intermediate layer is disposed on the light absorption layer and has a first boundary, wherein the intermediate layer is an I-type semiconductor layer or a graded refractive index layer. The multiplication/window layer is disposed on the intermediate layer and has a second boundary, wherein in a top view, the first boundary surrounds the second boundary, and a distance between the first boundary and the second boundary is greater than or equal to 1 micrometer. The non-diffusion type photodiode can reduce generation of dark current.

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 invention is directed to electrical circuits and methods. According to a specific embodiment, the present invention provides a voltage compensation mechanism for one or more single-phone avalanche diodes (SPADs). A reference voltage is generated based at least on an operating voltage of the SPADs. The reference voltage is coupled to a charge pump that generates a compensation voltage for the diodes. There are other embodiments as well.

A photoelectric conversion apparatus comprising an avalanche diode disposed in a semiconductor layer having a first surface and a second surface, wherein the avalanche diode includes a first semiconductor region disposed at a first depth, a second semiconductor region disposed at a second depth deeper from the second surface than the first depth, a third semiconductor region disposed at an edge of the first semiconductor region, a first wiring connected to the first semiconductor region, a second wiring connected to the second semiconductor region, and a third wiring not connected to the semiconductor layer, at least a part of the third wiring overlapping with the third semiconductor region in a planar view, and wherein a third voltage to be supplied to the third wiring is a value between a first voltage to be supplied to the first wiring and a second voltage to be supplied to the second wiring.

A photoelectric conversion apparatus comprising an avalanche diode disposed in a semiconductor layer having a first surface and a second surface, wherein the avalanche diode includes a first semiconductor region disposed at a first depth, a second semiconductor region disposed at a second depth deeper from the second surface than the first depth, a third semiconductor region disposed at an edge of the first semiconductor region, a first wiring connected to the first semiconductor region, a second wiring connected to the second semiconductor region, and a third wiring not connected to the semiconductor layer, at least a part of the third wiring overlapping with the third semiconductor region in a planar view, and wherein a third voltage to be supplied to the third wiring is a value between a first voltage to be supplied to the first wiring and a second voltage to be supplied to the second wiring.

A single-photon detection pixel includes a substrate, a first well provided in the substrate, a pair of heavily doped regions provided on the first well, and a contact provided between the pair of heavily doped regions, wherein the substrate and the pair of heavily doped regions have a first conductivity type, and the first well and the contact have a second conductivity type that is different from the first conductivity type.

A single-photon detection pixel includes a substrate, a first well provided in the substrate, a pair of heavily doped regions provided on the first well, and a contact provided between the pair of heavily doped regions, wherein the substrate and the pair of heavily doped regions have a first conductivity type, and the first well and the contact have a second conductivity type that is different from the first conductivity type.

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.

Techniques are disclosed to enable a system for wide-range scanning of objects in three-dimensions. A broad-beam, laser-based transmitter is provided that is adapted to generate a scanning signal to be transmitted in a scanning direction toward an object to be scanned, a portion of the scanning signal being reflected by the object to be scanned. Additionally, a scanning signal collection lens is provided that is adapted to receive the portion of reflected scanning signal and to direct the reflected scanning signal to a mirror array, the mirror array adapted to selectively direct a directed portion of the reflected scanning signal as well as a detector lens adapted to receive the directed scanning signal, the collection lens adapted to focus the directed scanning signal resulting in a focused directed signal and a photoelectric detector adapted to convert the focused directed scanning signal into at least one electronic representation of a two-dimensional image. A rotational motor is provided that is adapted to rotate the system with respect to the area being scanned.