A method for fabricating an image sensor in accordance with an embodiment of the inventive concepts may include forming first and second photodiodes within a substrate, forming first and second gate electrodes over the substrate, the first gate electrode vertically partially overlapping the first photodiode and the second gate electrode vertically partially overlapping the second photodiode, forming an impurity injection region comprising first and second type impurities between the first and the second gate electrodes, and performing an annealing process to form a floating diffusion region comprising the first type impurities and a channel region comprising the second type impurities. The channel region surrounds lateral surfaces and a bottom surface of the floating diffusion region.

Various embodiments of the present disclosure are directed towards an image sensor. The image sensor includes a first semiconductor substrate having a photodetector and a floating diffusion node. A transfer gate is disposed over the first semiconductor substrate, where the transfer gate is at least partially disposed between opposite sides of the photodetector. A second semiconductor substrate is vertically spaced from the first semiconductor substrate, where the second semiconductor substrate comprises a first surface and a second surface opposite the first surface. A readout transistor is disposed on the second semiconductor substrate, where the second surface is disposed between the transfer gate and a gate of the readout transistor. A first conductive contact is electrically coupled to the transfer gate and extending vertically from the transfer gate through both the first surface and the second surface.

A sensing device includes a light source to emit light, a light sensor to detect reflection of the emitted light and distance determination circuitry responsive to reflected-light detection within the light sensor. The light sensor includes a photodetector having a photocharge storage capacity in excess of one electron and an output circuit that generates an output signal responsive to light detection within the photodetector with sub-hundred nanosecond latency. The distance determination circuitry measures an elapsed time based on transition of the output signal in response to photonic detection within the photodetector and determines, based on the elapsed time, a distance between the sensing device and a surface that yielded the reflection of the emitted light.

To provide a semiconductor device which has transistor characteristics with little variation and includes an oxide semiconductor. The semiconductor device includes an insulating film over a conductive film and an oxide semiconductor film over the insulating film. The oxide semiconductor film includes a first oxide semiconductor layer, a second oxide semiconductor layer over the first oxide semiconductor layer, and a third oxide semiconductor layer over the second oxide semiconductor layer. The energy level of a bottom of a conduction band of the second oxide semiconductor layer is lower than those of the first and third oxide semiconductor layers. An end portion of the second oxide semiconductor layer is positioned on an inner side than an end portion of the first oxide semiconductor layer.

Semiconductor devices and methods of fabricating such devices are provided. The devices include source and drain regions on one conductivity type separated by a channel length and a gate structure. The devices also include a channel region of the one conductivity type formed in the device region between the source and drain regions and a screening region of another conductivity type formed below the channel region and between the source and drain regions. In operation, the channel region forms, in response to a bias voltage at the gate structure, a surface depletion region below the gate structure, a buried depletion region at an interface of the channel region and the screening region, and a buried channel region between the surface depletion region and the buried depletion region, where the buried depletion region is substantially located in channel region.

Semiconductor devices and methods of forming semiconductor devices are disclosed. In some embodiments, a first trench and a second trench are formed in a substrate, and dopants of a first conductivity type are implanted along sidewalls and a bottom of the first trench and the second trench. The first and second trenches are filled with an insulating material, and a gate dielectric and a gate electrode over the substrate, the gate dielectric and the gate electrode extending over the first trench and the second trench. Source/drain regions are formed in the substrate on opposing sides of the gate dielectric and the gate electrode.

Provided is a complementary metal-oxide-semiconductor (CMOS) image sensor. The CMOS image sensor can include a substrate having a first device isolation layer defining and dividing a first active region and a second active region, a photodiode disposed in the substrate and can be configured to vertically overlap the first device isolation layer, a transfer gate electrode can be disposed in the first active region and can be configured to vertically overlap the photodiode, and a floating diffusion region can be in the first active region. The transfer gate electrode can be buried in the substrate.

An imaging device with excellent imaging performance is provided. In the imaging device, a first layer, a second layer, and a third layer have a region overlapping with one another, the first layer and the second layer each include transistors, and the third layer includes a photoelectric conversion element. Off-state currents of the transistors formed in the first layer are lower than those of the transistors formed in the second layer, and field-effect mobilities of the transistors formed in the second layer are higher than those of the transistors formed in the first layer.

Channel stop sections formed by multiple times of impurity ion implanting processes. Four-layer impurity regions are formed across the depth of a semiconductor substrate (across the depth of the bulk), so that a P-type impurity region is formed deep in the semiconductor substrate; thus, incorrect movement of electric charges is prevented. Other four-layer impurity regions of another channel stop section are decreased in width step by step across the depth of the substrate, so that the reduction of a charge storage region of a light receiving section due to the dispersion of P-type impurity in the channel stop section is prevented in the depth of the substrate.

A semiconductor device is provided that includes an array of imaging cells realized from a plurality of layers formed on a substrate, wherein the plurality of layers includes at least one modulation doped quantum well structure spaced from at least one quantum dot structure. Each respective imaging cell includes an imaging region spaced from a corresponding charge storage region. The at least one quantum dot structure of the imaging region generates photocurrent arising from absorption of incident electromagnetic radiation. The at least one modulation doped quantum well structure defines a buried channel for lateral transfer of the photocurrent for charge accumulation in the charge storage region and output therefrom. The at least one modulation doped quantum well structure and the at least one quantum dot structure of each imaging cell can be disposed within a resonant cavity that receives the incident electromagnetic radiation or below a structured metal film having a periodic array of holes.