A uniform bridge gradient (UBG) time-of-flight (ToF) photodiode block is described, such as for integration with image sensor pixels. The UBG ToF photodiode block can be part of a UBG ToF pixel, and an image sensor can include an array of such pixels. Each UGB ToF photosensor block has multiple taps for selective activation, and a photodiode region designed for complete and rapid transit of photocarriers, as they are generated, via the multiple taps. Embodiments of the photodiode region include a photodiode-defining implant, a relatively shallow first bridging implant, and relatively deep second bridging implant. The bridging implants provide lateral bridging with a uniform doping gradient near and across the multiple taps.

The present disclosure relates to a CMOS image sensor, and an associated method of formation. In some embodiments, the CMOS image sensor comprises a substrate and a transfer gate disposed from a front-side surface of the substrate. The CMOS image sensor further comprises a photo detecting column disposed at one side of the transfer gate within the substrate. The photo detecting column comprises a doped sensing layer comprising one or more recessed portions along a circumference of the doped sensing layer in parallel to the front-side surface of the substrate. By forming the photo detecting column with recessed portions, a junction interface is enlarged compared to a previous p-n junction interface without recessed portions, and thus a full well capacity of the photodiode structure is improved.

An image sensor including a plurality of avalanche photodiodes formed inside and on top of a semiconductor substrate of a first conductivity type having a front side and a back side, wherein: trenches vertically extend in the substrate from its front side to its back side, the trenches having, in top view, the shape of a continuous grid laterally delimiting a plurality of substrate islands, each island defining a pixel including a single individually-controllable avalanche photodiode, and including a doped area of collection of an avalanche signal of the pixel photodiode the lateral walls of the trenches are coated with a first semiconductor layer having a conductivity type opposite to that of the collection area, and a conductive region extends in the trenches, the conductive region being in contact with the surface of the first semiconductor layer opposite to the substrate.

A method of forming a semiconductor device includes: forming a patterned hard mask layer on a semiconductor substrate; performing a first etching process to form a recess in an exposed portion of the semiconductor substrate, using a first etchant that includes a first halogen species; performing a second etching process using a second etchant that includes a second halogen species, such that the second halogen species forms a barrier layer in the semiconductor substrate, surrounding the recess; and growing a detection region in the recess using an epitaxial growth process. The barrier layer is configured to reduce diffusion of the first halogen species into the detection region.

An image sensor includes a photodiode disposed in a substrate and including an n-type impurity region, wherein the n-type impurity region is doped with n-type impurities, a transfer gate (TG) structure partially buried in the substrate and disposed on the n-type impurity region, a recess disposed at an upper surface of the substrate and being spaced apart from the TG structure, a floating diffusion (FD) region disposed under the recess and doped with n-type impurities, and an impurity region disposed at a portion of the substrate between the TG structure and the recess and doped with p-type impurities. An upper surface of the FD region is lower than an upper surface of the impurity region.

An image sensor includes a substrate including a first surface on which light is incident and a second surface opposite to the first surface, unit pixels in the substrate, each including a photoelectric conversion layer, color filters on the first surface of the substrate, a grid pattern on the first surface of the substrate defining a respective light receiving area of each of the unit pixels, and microlenses on the color filters, each of the microlenses corresponding to a respective one of the unit pixels, wherein the unit pixels include a first pixel and a second pixel sharing a first color filter which is one of the color filters, and a first light receiving area of the first pixel is different from a second light receiving area of the second pixel.

An imaging device includes a semiconductor substrate and pixels. Each of the pixels includes a first capacitive element including a first electrode provided above the semiconductor substrate, a second electrode provided above the semiconductor substrate, and a dielectric layer located between the first electrode and the second electrode. At least one selected from the group consisting of the first electrode and the second electrode has a first electrical contact point electrically connected to a first electrical element and a second electrical contact point electrically connected to a second electrical element different from the first electrical element. The first capacitive element includes at least one trench portion having a trench shape.

An image sensor structure including a substrate, a nanowire structure, a first conductive line, a second conductive line, and a third conductive line is provided. The nanowire structure includes a first doped layer, a second doped layer, a third doped layer, and a fourth doped layer sequentially stacked on the substrate. The first doped layer and the third doped layer have a first conductive type. The second doped layer and the fourth doped layer have a second conductive type. The first conductive line is connected to a sidewall of the second doped layer. The second conductive line is connected to a sidewall of the third doped layer. The third conductive line is connected to the fourth doped layer.

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.

A fingerprint sensor includes: a thin film transistor disposed on a substrate; a first insulating layer disposed on the thin film transistor; a first sensing electrode disposed on the first insulating layer and connected to the thin film transistor; a second insulating layer disposed on the first sensing electrode and including an opening exposing the first sensing electrode; a sensing semiconductor layer disposed in the opening of the second insulating layer and on the first sensing electrode, and including an N-type semiconductor layer, an I-type semiconductor layer, and a P-type semiconductor layer; and a second sensing electrode disposed on the sensing semiconductor layer. An upper surface of the sensing semiconductor layer and an upper surface of the second insulating layer are coplanar.