A photodetector including a substrate having a semiconductor material layer, such as a silicon-containing layer, and a germanium-based well embedded in the semiconductor material layer, where a gap is located between a lateral side surface of the germanium-based well and the surrounding semiconductor material layer. The gap between the lateral side surface of the germanium-based well and the surrounding semiconductor material layer may reduce the surface contact area between the germanium-containing material of the well and the surrounding semiconductor material, which may be a silicon-based material. The formation of the gap located between a lateral side surface of the germanium-based well and the surrounding semiconductor material layer may help minimize the formation of crystal defects, such as slips, in the germanium-based well, and thereby reduce the dark current and improve photodetector performance.

An optical semiconductor device with cascade vias is disclosed. The semiconductor device a logic die having a core circuit area and a logic peripheral circuit area; a memory die positioned on the logic die and having a memory cell area and a memory peripheral area; a first inter-die via positioned in the memory peripheral area; a landing pad positioned on the first inter-die via; and a sensor die positioned on the memory die and including a sensor pixel area and a sensor peripheral area, a first intra-die via positioned in the sensor peripheral area. The first inter-die via and the first intra-die via are electrically coupled through the landing pad in a cascade manner.

A multilayer device includes a substrate and a first layer disposed on the substrate. A trench extends through one or both of the substrate and the first layer. The trench has a first sidewall spaced apart from a second sidewall, each sidewall extending from an upper surface of the substrate to a lower surface of the first layer. An optically active region is disposed on the first layer overlying the trench, such that at least a portion of the optically active region is located within a set of lines corresponding to the sidewalls of the trench.

A method comprises providing a cavity structure on the substrate comprising a first growth channel extending in a first direction, a second growth channel extending in a second direction, wherein the second direction is different from the first direction and the second channel is connected to the first channel at a channel junction, a first seed surface in the first channel, at least one opening for supplying precursor materials to the cavity structure, selectively growing from the first seed surface a first semiconductor structure substantially only in the first direction and in the first channel, thereby forming a second seed surface for a second semiconductor structure at the channel junction, growing in the second channel the second semiconductor structure in the second direction from the second seed surface, thereby forming the semiconductor junction comprising the first and the second semiconductor structure.

A method comprises providing a cavity structure on the substrate comprising a first growth channel extending in a first direction, a second growth channel extending in a second direction, wherein the second direction is different from the first direction and the second channel is connected to the first channel at a channel junction, a first seed surface in the first channel, at least one opening for supplying precursor materials to the cavity structure, selectively growing from the first seed surface a first semiconductor structure substantially only in the first direction and in the first channel, thereby forming a second seed surface for a second semiconductor structure at the channel junction, growing in the second channel the second semiconductor structure in the second direction from the second seed surface, thereby forming the semiconductor junction comprising the first and the second semiconductor structure.

There is provided a photodiode array including a semiconducting substrate and a plurality of photodiodes that are disposed at a surface of the substrate. Each photodiode is laterally spaced apart from neighboring photodiodes by a lateral substrate surface region. An optical interface surface of the substrate is arranged for accepting external input radiation. A plurality of electrically conducting fuses are disposed on the substrate surface. Each fuse is connected to a photodiode in the plurality of photodiodes. Each fuse is disposed at a lateral substrate surface region that is spaced apart from neighboring photodiodes in the plurality of photodiodes.

A optical sensing device includes a substrate, an optical acting area and a filter layer. The optical acting area is disposed on the substrate. The filter layer covers the optical acting area and selectively allows only a light beam with a specific wavelength to pass through and be received by the optical acting area while blocking the light beams with other wavelengths. Each of the two sides of the substrate has a bevel structure. The filter layer covers each bevel structure of each side to prevent the light beams with other wavelengths from passing through the two sides of the substrate being received by the optical acting area.

A light sensor includes a lower electrode layer, an absorption layer and an upper electrode layer. The absorption layer is located on the lower electrode layer, in which the absorption layer includes a material that has an electron mobility greater than 300 cm.sup.2/Vs and greater than twice as many as a hole mobility. The upper electrode layer is located on the absorption layer, and is configured to collect the scattered high-speed excess electrons and to leave low-speed excess holes near the edges of the upper electrode layer. A downward photocurrent is generated by the photovoltage in the absorption layer due to the formation of positively charged region near the upper surface.

A light receiving device includes a substrate having a principal surface and a back surface, the substrate containing GaSb semiconductor co-doped with a p-type dopant and an n-type dopant; a stacked semiconductor layer disposed on the principal surface of the substrate, the stacked semiconductor layer including an optical absorption layer; and an incident surface provided on the back surface of the substrate that receives an incident light. The optical absorption layer includes a super-lattice structure including a first semiconductor layer and a second semiconductor layer that are alternately stacked. In addition, the first semiconductor layer contains gallium and antimony as constituent elements. The second semiconductor layer is composed of a material different from a material of the first semiconductor layer.

Described herein is a pinned photodiode pixel architecture having a p-type substrate that is independently biased with respect to a pixel area to provide an avalanche region between an n-type region and a p-type region formed on the substrate. Such a pinned photodiode pixel can be used in imaging sensors that are used in low light level conditions.