150 results about "Avalanche multiplication" patented technology

The present invention provides a photodiode comprising a p-i-n or pn junction at least partly formed by first and second regions (2) made of semiconductor materials having opposite conductivity type, wherein the p-i-n or pn junction comprises a light absorption region (11) for generation of charge carriers from absorbed light. One section of the p-i-n or pn junction is comprises by one or more nanowires (7) that are spaced apart and arranged to collect charge carriers generated in the light absorption region (11). At least one low doped region (10) made of a low doped or intrinsic semiconductor material provided between the nanowires (7) and one of said first region (1) and said second region (2) enables custom made light absorption region and/or avalanche multiplication region of the active region (9).

A wavelength conversion device includes a photodetector for generating a photocurrent in response to the detection of radiation at a first wavelength. An avalanche multiplier amplifies the signal photocurrent and feeds this to a light emitting element that produces radiation at a second wavelength shorter than the first wavelength and corresponding to the detected radiation at the first wavelength. The components are assembled together in an integrated stacked arrangement either by epitaxial growth or wafer fusion of the individual components. The device is useful as an image intensifier or thermal imaging device.

In order to operate a single photon detector in communication wavelength band at a high speed, a DC bias voltage 2 lower than the breakdown voltage is applied to an InGaAs/InP avalanche photodiode (APD) 1. A 500 MHz sine wave gating signal 3 is superimposed with the DC bias voltage 2 and applied to the APD so as to exceed the breakdown voltage by about 4V in a fractional time of each period. The sine wave gating signal 3 passed through the APD 1 is substantially completely removed by a filter 4, thereby improving S/N and enabling to detect a single photon even if the avalanche multiplication time is shortened to reduce the after pulse and the detection period. As a result, it achieves to detect a single photon in the 1550 nm communication band at a high speed.

A metal oxide semiconductor field effect transistor (MOSFET) in a non-volatile memory cell has a source, a drain and a channel region between the source and the drain, all formed in a substrate of opposite conductivity type to the conductivity type of the source and drain. The MOSFET is programmed by connecting the drain electrode to the supply source of the main voltage, V_cc, provided to said non-volatile memory cell and supplying selected voltages to the source and substrate so as to invert a portion of the channel region extending from the source toward the drain. The inverted portion of the channel region ends at a pinch-off point before reaching the drain. By controlling the reverse bias across the PN junction between the source and the substrate, the pinch-off point of the inversion region is pulled back toward the source thereby to increase the programming efficiency of the MOSFET.

Methods and structures for highly efficient Hot Carrier Injection (HCI) programming for Non-Volatile Memories (NVM) apply the main positive supply voltage V_cc to, the drain electrode of the NVM cell from the chip main voltage supply in contrast to the conventional method using a higher voltage than V_cc. The source electrode and substrate are reverse biased with a differential voltage relative to the drain, while a voltage pulse is applied to the control gate of the NVM cell to turn on the NVM cell for programming. To optimize the programming condition, the source voltage and the substrate voltage are then adjusted to achieve the maximum threshold voltage shifts under the same applied gate voltage pulse condition (i.e. using a gate pulse with the same voltage amplitude and duration regardless of the source voltage and the substrate voltage). The substrate voltage to the drain voltage can not exceed the avalanche multiplication junction breakdown for a small programming current during the bias voltage adjustment.

The invention belongs to the fields of photoelectric detection and image sensors, and in order to inhibit fringe field and reduce device dark current while guaranteeing a high field in the central area of the device, reference basis is provided for industrial application. The invention discloses a two-stage table-top InGaAs/InP avalanche photodiode and a preparation method thereof. The structure comprises an N<+>-InP substrate, an N-InP buffer layer, an N<->-InGaAs In0.53Ga0.47As absorbed layer, an N-InGaAsP In(1-x)GaxAsyP(1-y) component gradient layer, an N-InP charge layer, an i-InP multiplying layer, a P-InP field buffer layer and a P<+>-InP contact layer, wherein the P-InP field buffer layer forms a shallow table-top through etching, the N-InP buffer layer forms a deep table-top through etching, and constant impact ionization of photon-generated carriers inside the multiplying layer causes avalanche multiplication. The avalanche photodiode is mainly applied to the design occasionsof photoelectric detection and photoelectric sensors.

A semiconductor photodetector for photon detection without the use of avalanche multiplication, and capable of operating at low bias voltage and without excess noise. In one embodiment, the photodetector comprises a plurality of InP/AlInGaAs/AlGaAsSb layers, capable of spatially separating the electron and the hole of an photo-generated electron-hole pair in one layer, transporting one of the electron and the hole of the photo-generated electron-hole pair into another layer, focalizing it into a desired volume and trapping it therein, the desired volume having a dimension in a scale of nanometers to reduce its capacitance and increase the change of potential for a trapped carrier, and a nano-injector, capable of injecting carriers into the plurality of InP/AlInGaAs/AlGaAsSb layers, where the carrier transit time in the nano-injector is much shorter than the carrier recombination time therein, thereby causing a very large carrier recycling effect.

An avalanche photodiode including a first electrode; and a substrate including a first semiconductor layer of a first conduction type electrically connected to the first electrode, in which at least an avalanche multiplication layer, a light absorption layer, and a second semiconductor layer of a second conduction type with a larger band gap than the light absorption layer are deposited on the substrate. The second semiconductor layer is separated into inner and outer regions by a groove formed therein, the inner region electrically connected to a second. With the configuration, the avalanche photodiode has a low dark current and high long-term reliability. In addition, the outer region includes an outer trench, and at least the light absorption layer is removed by the outer trench to form a side face of the light absorption layer. With the configuration, the dark current can be further reduced.

An image sensor includes an imaging area including a plurality of cells arrayed in a matrix on a semiconductor substrate, each of the cells including an avalanche photodiode, the avalanche photodiode including: an anode region buried in an upper portion of the semiconductor substrate; a cathode region buried in the upper portion of the semiconductor substrate separated from the anode region in a direction parallel to the surface of the semiconductor substrate; and an avalanche multiplication region defined between the anode and cathode regions, the avalanche multiplication region having an impurity concentration less than the anode and cathode regions; wherein depths of the anode and cathode regions from the surface of the semiconductor substrate are different from each other.

The invention discloses an SPAD with high detection efficiency and low dark count based on a standard CMOS process. The SPAD is prepared on a P substrate that is provided based on the CMOS process; anN-buried layer is arranged on the P substrate to play an isolation role, the buried N-type injection has the characteristic of inverted doping distribution, the doping concentration increases with the increase of depth, and a virtual protection ring is formed; an N-well region, a P-well region and a heavily doped P+ region are respectively arranged in a diffusion doping region of the N-buried layer, and the N-well region is taken as a component part of a photosensitive PN junction; the P-well region serves as a protection ring; the heavily doped P+ region, a shallow P-well region and the N-type region jointly form a P+P-/N-well photosensitive PN junction, and the combination of two P-type injections with different concentrations form a gradient junction to reduce the dark count of devices; the depletion region of the PN junction is the main occurrence region of avalanche multiplication, and meanwhile, the heavily doped P+ region is also taken as an anode contact region of a photodetector; an N-well contact region is arranged in the N-well region at the edge, and the N-well contact region is a heavily doped N+ region and serves as a cathode contact region of the photodetector.

A semiconductor photodetector has at least one unit pixel having a photoelectric conversion part, a charge storage part, and a detection circuit. The photoelectric conversion part includes a charge multiplication region in which incident light is converted into a charge, and the charge is multiplied by avalanche multiplication. The charge storage part is connected to the photoelectric conversion part and stores a signal charge from the photoelectric conversion part. The detection circuit is connected to the charge storage part, converts the signal charge stored in the charge storage part into a voltage, passes the voltage through an amplifier to amplify the voltage, and outputs the amplified voltage.

The invention relates to an InP base plane type back incident avalanche optoelectronic diode which comprises a substrate, a buffer layer manufactured on the substrate, an absorption layer manufactured on the buffer layer, a transition layer manufactured on the absorption layer, an electric field control layer manufactured on the transition layer and an avalanche multiplication layer manufactured on the electric field control layer, wherein a concave part is disposed on a central area on the avalanche multiplication layer, and the edge of the concave part is of an inverse step-shaped structure; a floating protective ring is manufactured at the outside of the concave part on the avalanche multiplication layer; the concave part comprises a P-type doped layer disposed on the bottom surface of the concave part and a passivation protecting layer disposed on the surfaces of the P-type doped layer and the avalanche multiplication layer, wherein a contact through hole is disposed in the center of the passivation protecting layer, and a P electrode is manufactured at the bottom in the middle of the passivation protecting layer; and an n electrode is manufactured on the back of the substrate, and a light incident window is disposed in the middle of the n electrode.

The invention discloses an aluminum gallium nitride (AlGaN) base solar-blind ultraviolet detector. The aluminum gallium nitride (AlGaN) base solar-blind ultraviolet detector comprises a sapphire substrate, an A1N nucleation layer, an Alx1Ga1-x1N buffer layer, an n-type Alx2Gal-x2N layer, a non-doped i-type Zny1Mg1-y1O absorption layer, an n-type ZnO/Zny2Mg1-y2O superlattice separation layer, a non-doped i-type Zny3Mg1-y3O multiplication layer, a p-type Alx3Ga1-x3N layer, and a p-type GaN layer. An n-type ohmic electrode is led out from the n-type Alx2Gal-x2N layer, and a p-type ohmic electrode is led out from the p-type GaN layer. The invention also discloses the preparation method the aluminum gallium nitride (AlGaN)base solar-blind ultraviolet detector. The aluminum gallium nitride (AlGaN) base solar-blind ultraviolet detector is capable of improving the solar-blind ultraviolet detector avalanche multiplication factor and the responsibility of the detector.