Abstract: A semiconductor light-receiving device includes: a first conduction layer of a first conduction type; a light absorption layer provided on the first conduction layer; a multiplication layer provided on the light absorption layer; a window layer provided on the multiplication layer, the window layer being undoped or having the first conduction type; and a second conduction region provided in the window layer by impurity diffusion, the second conduction region having a band gap wider than that of the light absorption layer and having a second conduction type different from the first conduction type. The following condition is satisfied: X/W?(M?1)2/(2M) where W is a film thickness from a lower surface of the light absorption layer and an upper surface of the multiplication layer, X is a film thickness of the second conduction region, and M is a multiplication factor.

Abstract: A photodetector for use at wavelengths of 2 ?m and longer has an intersubband absorption region to provide absorption at wavelengths beyond 2 ?m, integrated with an avalanche multiplier region to provide low-noise gain. In one particular design, the intersubband absorption region is a quantum-confined absorption region (e.g., based on quantum wells and/or quantum dots).

Abstract: An objective is to provide an avalanche photodiode that is excellent in device characteristics such as reliability. An avalanche photodiode is provided, which includes a substrate 1 formed with a light receiving region 3 on a multiplication layer 119, and formed with layers of differing semiconductor type with the multiplication layer 119 intervening, a ring-shaped groove 7 formed on the end face of the substrate 1 on its light-receiving-region side, in such a way that the groove surrounds the light receiving region 3, and one or more steps 5 provided on a side wall of the ring-shaped groove 7, in a range of from ¼ to ¾ of the depth of the groove.

Abstract: A photodetector is described. The photodetector is comprised of a substrate, a first n-type III-V compound semiconductor layer located on the substrate, an n++-type III-V compound semiconductor layer located on a first portion of the first n-type III-V compound semiconductor layer with a second portion of the first n-type III-V compound semiconductor layer exposed, a p-type III-V compound semiconductor layer located on the n++-type compound semiconductor layer, an undoped III-V compound semiconductor layer located on the p-type III-V compound semiconductor layer, a second n-type III-V compound semiconductor layer located on the undoped III-V compound semiconductor layer, a conductive transparent oxide layer located on the second n-type III-V compound semiconductor layer, a first electrode located on a portion of the conductive transparent oxide layer, and a second electrode located on a portion of the second portion of the first n-type III-V compound semiconductor layer.

Abstract: A semiconductor light-receiving device has a substrate including upper, middle and lower regions in its front side. A p-type layer on the lower region has a top surface including a portion on a level with the middle region. An electrode covers at least part of the boundary between the portion of the p-type layer and the middle region. An n-type layer on the p-type layer has a top surface including a portion on a level with the upper region. Another electrode covers at least part of the boundary between the portion of the n-type layer and the upper region.

Abstract: A semiconductor waveguide based optical receiver is disclosed. An apparatus according to aspects of the present invention includes an absorption region defined along an optical waveguide. The absorption region includes a first type of semiconductor material having a first refractive index. The apparatus also includes a multiplication region defined along the optical waveguide. The multiplication region is proximate to and separate from the absorption region. The multiplication region includes a second type of semiconductor material having a second refractive index. The first refractive index greater than the second refractive index such that an optical beam directed through the optical waveguide is pulled towards the absorption region from the multiplication region and absorbed in the absorption region to create electron-hole pairs from the optical beam. The multiplication region includes first and second doped regions defined along the optical waveguide.

Abstract: Electromagnetic energy is detected with high efficiency in the spectral range having wavelengths of about 1–2 microns by coupling an absorber layer having high quantum efficiency in the spectral range having wavelengths of about 1–2 microns to an intrinsic semiconducting blocking region of an impurity band semiconducting device included in a solid state photon detector.

Abstract: An avalanche photodiode has improved low-noise characteristics, high-speed response characteristics, and sensitivity. The avalanche photodiode includes a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, a semiconductor multiplication layer interposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer, and a semiconductor light-absorbing layer interposed between the semiconductor multiplication layer and the second conductivity type semiconductor layer. The avalanche photodiode further comprises a multiplication suppressing layer which suppresses multiplication of charge carriers in the semiconductor light-absorbing layer, has a thickness of 0.6 ?m or less, and is located between the semiconductor light-absorbing layer and the second conductivity type semiconductor layer. The thickness of the semiconductor light-absorbing layer is 0.5 ?m or more.

Abstract: A solid-state imaging device is provided which has preferable linearity of signal outputs according to light intensities and does not cause dark defects even at a low light intensity. The solid-state imaging device comprises: a ring gate having a non-uniform width; a source region formed inside the ring gate; a drain region formed surrounding a circumference of the ring gate; and a carrier pocket formed under the ring gate, wherein a region where (X divided by Y) is the smallest substantially coincides with a region where Z is the shortest; X is a pocket-to-source distance; Y is a pocket-to-drain distance; and Z is a source-to-drain distance.

Abstract: An active pixel includes a a photosensitive element formed in a semiconductor substrate. A transfer transistor is formed between the photosensitive element and a floating diffusion and selectively operative to transfer a signal from the photosensitive element to the floating diffusion. The floating diffusion is formed from an n-type implant with a dosage in the range of 5e13 to 5e14 ions/cm2. Finally, an amplification transistor is controlled by the floating diffusion.

Abstract: An interline transfer type image sensing device that can be operated at high speed and with low image smear is described. The device incorporates a refractory metal layer which is used for both a light shield over the vertical charge transfer region and as a wiring layer for low resistance strapping of poly crystalline silicon (polysilicon) gate electrodes for the vertical charge transfer region. Plugs provided by a separate metallization layer connect the refractory light shield to the polysilicon gate electrode. These plugs allow high temperature processing after refractory light shield patterning for improved sensor performance without degradation of the polysilicon gate electrode or the refractory lightshield layer.

Abstract: A plurality of N-type diffusion layers are formed a specified distance apart on a P-type semiconductor layer. A P-type leak prevention layer formed between at least N-type diffusion layers prevents leaking between the diffusion layers. A dielectric film is formed in at least a light incident area on a P-type semiconductor layer including the diffusion layers and the leak prevention layer. Accordingly, provided are a split type light receiving element positively functioning as a split type light receiving element even when charge is accumulated in the dielectric film and having a uniform sensitivity throughout the entire area on a light receiving surface, and a circuit-built-in light receiving element and an optical disk device using the split type light receiving element.

Abstract: A semiconductor photodetection device includes a semiconductor structure including an optical absorption layer having a photo-incidence surface on a first side thereof, a dielectric reflecting layer formed on a second side of the semiconductor structure opposite to the first side, a contact electrode surrounding the dielectric reflecting layer and contacting with the semiconductor structure, and a close contact electrode covering the dielectric reflecting layer and contacting with the contact electrode and the dielectric reflecting layer, wherein the close contact electrode adheres to the dielectric reflecting layer more strongly than to the contact electrode.

Abstract: There is a demand of a solid-state imaging device capable of being driven at a high speed and in which the shading of sensitivity and illuminance defect can be prevented from being caused. A solid-state imaging device (20) includes a light-receiving sensor section disposed on the surface layer portion of a substrate (21) that performs a photoelectric conversion, a charge transfer section that transfers a signal charge read out from the light-receiving sensor section, a transfer electrode (27) (28) made of polysilicon formed on a substrate (21) at a position approximately above the charge transfer section through an insulating film (26), and an interconnection made of polysilicon and interconnected to the transfer electrode (27) (28). At least one of the polysilicon transfer electrode (27)(28) and the interconnection is formed on a polysilicon layer (27a) (28a) by selectively depositing a high-melting point metal having a resistance value lower than that of polysilicon.

Abstract: An optical receiver includes an avalanche photodiode (APD) having a light-receiving area provided on a face of a first substrate, the light-receiving area receiving a part of signal light; a photodetector having a light-receiving area provided on a face of a second substrate, the light-receiving area receiving the other part of the signal light; and a mounting member having a principal plane on which the APD and the photodetector are mounted. Due to this structure, crosstalk between the APD and the photodetector does not occur and an avalanche multiplication factor of the APD can be controlled on the basis of the output current of the photodetector.

Abstract: An avalanche photodiode having a reduced capacitance is provided. The avalanche photodiode includes a wide band gap layer in its depletion region. The width of the wide band gap layer increases the extent of the depletion region, thereby reducing the capacitance while minimizing the impact on the dark current.

Abstract: An avalanche photodiode including a multiplication layer is provided. The multiplication layer may include a well region and a barrier region. The well region may include a material having a higher carrier ionization probability than a material used to form the barrier region.

Abstract: A semiconductor device has a structure reducing resistances to a high frequency current. The semiconductor device includes a semi-insulating substrate, a first n-type layer made of a compound semiconductor, and a first p-type layer made of a compound semiconductor in which a signal current flows in a lateral direction, parallel to the semi-insulating substrate. The first p-type layer is sandwiched between the semi-insulating substrate and the first n-type layer. A second n type layer made of a compound semiconductor is between the semi-insulating substrate and the first p type layer. An alternating current component of the signal current flows through the second n type layer.

Abstract: The invention provides a solid-state imaging device that can include a pixel array having a plurality of pixels arranged in a matrix. The pixels can each include a photo diode that generates carriers depending on the intensity of incident light, an accumulation region that accumulates the generated carriers, an insulated-gate output transistor that outputs a signal according to threshold voltage that changes depending on the number of carriers accumulated in the accumulation region, and an insulated-gate clear transistor that discharges carriers accumulated in the accumulation region. The carriers accumulated in the accumulation region are discharged through a channel region of the clear transistor. Accordingly, the invention can provide a technique where carriers in an accumulation region can be easily discharged.

Abstract: A process for forming at least one interface region between two regions of semiconductor material. At least one region of dielectric material comprising nitrogen is formed in the vicinity of at least a portion of a boundary between the two regions of semiconductor material, thereby controlling electrical resistance at the interface.

Abstract: A horizontal access semiconductor photo detector (2) comprises a horizontal light absorbing layer (8) for converting light into photo-current which layer is configured to confine light within it in whispering gallery modes of propagation. The detector is configured to have a first waveguide portion (18) and a second light confining portion (20, 21) arranged such that the waveguide portion couples light into the detector and transfers light into the light confining portion so as to excite whispering gallery modes of propagation around the light confining portion. The light absorbing layer may be part of the light confining portion or alternatively light can be coupled into the light confining portion or alternatively light can be coupled into the light absorbing layer from the light confining portion by evanescent coupling. The excitation of whispering gallery modes within the light absorbing layer significantly increases the effective absorption coefficient of the light absorbing layer.

Abstract: An avalanche photo-detector (APD) is disclosed, which can reduce device capacitance, operating voltage, carrier transport time and dark current as well as increasing response speed and output power. Thus, an avalanche photo-detector (APD) with high saturation power, high gain-bandwidth product, low noise, fast response, low dark current is achieved. The APD includes an absorption layer with graded doping for converting an incident light into carriers, an undoped multiplication layer for multiplying current by means of receiving carriers, a doped field buffer layer sandwiched between the absorption layer and the multiplication layer for concentrating an electric field in the multiplication layer when a bias voltage is applied, and an undoped drift layer sandwiched between the absorption layer and the field buffer layer for capacitance reduction.

Abstract: A blue-ultraviolet on-p-GaAs substrate pin Zn1-xMgxSySe1-y photodiode with high quantum efficiency, small dark current, high reliability and a long lifetime. The ZnMgSSe photodiode has a metallic p-electrode, a p-GaAs single crystal substrate, a p-(ZnSe/ZnTe)m superlattice (m: integer number of sets of thin films), an optionally formed p-ZnSe buffer layer, a p-Zn1-xMgxSySe1-y layer, an i-Zn1-xMgxSySe1-y layer, an n-Zn1-xMgxSySe1-y layer, an n-electrode and an optionally provided antireflection film. Incidence light arrives at the i-layer without passing ZnTe layers. Since the incidence light is not absorbed by ZnTe layers, high quantum efficiency and high sensitivity are obtained.

Abstract: In a photoelectric conversion element which is formed by alternately stacking a region of a first conductivity type and a region of a second conductivity type as a conductivity type opposite to the first conductivity type to form a multi-layered structure, in which junction surfaces between the neighboring regions of the first and second conductivity types are formed to have depths suited to photoelectrically convert light in a plurality of different wavelength ranges, and which outputs signals for respective wavelength ranges, a region of a conductivity type opposite to the conductivity type of a surface-side region of the junction surface closest to a surface is formed in the surface of the surface-side region. Thus, highly color-separable signals which suffer less color mixture upon reading out signals from a plurality of photodiode layers is read out.

Abstract: A process for forming at least one interface region between two regions of semiconductor material. At least one region of dielectric material comprising nitrogen is formed in the vicinity of at least a portion of a boundary between the two regions of semiconductor material, thereby controlling electrical resistance at the interface.

Abstract: A sequential mesa type avalanche photodiode (APD) includes a semiconductor substrate and a sequential mesa portion formed on the substrate. In the sequential mesa portion, a plurality of semiconductor layers, including a light absorbing layer and a multiplying layer, are laminated by epitaxial growth. In the plurality of semiconductor layers, a pair of semiconductor layers forming a pn junction is included. The carrier density of a semiconductor layer which is near to the substrate among the pair of semiconductor layers is larger than the carrier density of a semiconductor layer which is far from the substrate among the pair of semiconductor layers. In the APD, light-receiving current based on movement of electrons and positive holes generated in the sequential mesa portion when light is incident from the substrate toward the light absorbing layer is larger at a central portion than at a peripheral portion of the sequential mesa portion.

Abstract: A highly reflecting back illuminated diode structure allows light that has not been absorbed by a semiconductor absorbing region to be back reflected for at least a second pass into the absorbing region. The diode structure in a preferred embodiment provides a highly reflecting layer of gold to be supported in part by a conducting alloyed electrode ring contact and in part by a passivation layer of SixNy. Conveniently this structure provides a window within the contact which allows light to pass between the absorbing region and the reflecting layer of gold.

Abstract: There is provided a semiconductor photodetector which comprises (i) an InP substrate(1), (ii) an optical waveguide(5) having an N-type semiconductor layer(32) formed on the InP substrate(1), an optical waveguide core layer(3) formed on a partial area of the N-type semiconductor layer(32), and an upper cladding layer(4) formed on the optical waveguide core layer(3), and (iii) an avalanche photodiode(17) constructed by forming a photo absorbing layer(33), a heterobarrier relaxing layer(34), an underlying layer(14a) of a N-type field dropping layer(35), an overlying layer(14b) of the N-type field dropping layer(35), a carrier multiplying layer(36), and a P-type semiconductor layer(37) in sequence on another area of the N-type semiconductor layer(32), and coupled to the optical waveguide(5), wherein a side surface of the underlying layer(14a) of the N-type field dropping layer(35) comes into contact with a side surface of the optical waveguide core layer(3), and a part of the overlying layer(14b) of the N-type fi

Abstract: A wavelength-selective photo detector device includes a transparent upper electrode including a capacitor, a first semiconductor layer disposed under the upper electrode, an optical absorption layer disposed under the first semiconductor layer for absorbing light to form pairs of electrons and holes, an amplification layer disposed under the optical absorption layer for generating secondary electrons, a second semiconductor layer disposed under the amplification layer, and a lower electrode disposed under the second semiconductor layer and including an inductance coupled in parallel with an external resistance. The photo detector improves the S/N ratio and filters only light having a particular wavelength band.

Abstract: A novel structure for a photodiode is disclosed. It is comprised of a p-type region, which can be a p-substrate or p-well, extending to the surface of a semiconductor substrate. A multiplicity of parallel finger-like n-wells is formed in the p-type region. The fingers are connected to a conductive region at one end.

Abstract: In a photoelectric conversion device comprising a first-conductivity type first semiconductor region located in a pixel region, a second-conductivity type second semiconductor region provided in the first semiconductor region, and a wiring for electrically connecting the second semiconductor region to a circuit element located outside the pixel region, a shield is provided on the light-incident side of the wiring, via an insulator in such a way that it covers at least part of the wiring and also the shield comprises a conductor whose potential stands fixed. This photoelectric conversion device may hardly be affected with low-frequency radiated noises as typified by power-source noise.

Abstract: A blue-ultraviolet on-p-GaAs substrate pin Zn1-xMgxSySe1-y photodiode with high quantum efficiency, small dark current, high reliability and a long lifetime. The ZnMgSSe photodiode has a metallic p-electrode, a p-GaAs single crystal substrate, a p-(ZnSe/ZnTe)m superlattice (m: integer number of sets of thin films), an optionally formed p-ZnSe buffer layer, a p-Zn1-xMgxSySe1-y layer, an i-Zn1-xMgxSySe1-y layer, an n-Zn1-xMgxSySe1-y layer, an n-electrode and an optionally provided antireflection film. Incidence light arrives at the i-layer without passing ZnTe layers. Since the incidence light is not absorbed by ZnTe layers, high quantum efficiency and high sensitivity are obtained.

Abstract: A photodiode (111) and resistors (121) are formed on a semi-insulating InP substrate (101). The photodiode (111) is formed by subjecting a layered structure formed by successively depositing an n+-type InP cladding layer (102), an n-type InGaAsP core layer (103), a nondoped InGaAs active layer (104), a p-type InGaAsP core layer (105), and a p+-type InP cladding layer 106 on the InP substrate (101) to a selective etching process. The resistors (121) have the same layered structure as the photodiode (111). Photodiode (111) is connected to n-type wiring lines (131) and a p-type wiring line (141). Resistors (121) are connected to the n-type wiring lines (131) and the p-type wiring line (141) in parallel to the photodiode (111). A side surface on the side of the photodiode (111) of the InP substrate (101) is a cleavage plane, and the cleavage plane is coated with an antireflection film (161).

Abstract: A photodetector circuit incorporates an avalanche photodiode (APD) 300 produced by epitaxy on a CMOS substrate 302 with implanted n-well 304 and p-well 306. The n-well 304 has an implanted p+ guard ring 310 delimiting the APD 300. Within the guard ring 310 is an implanted n+ APD layer 312 upon which is deposited an epitaxial p+ APD layer 314, these layers forming the APD 300. The APD may be incorporated in an amplifier circuit 50 providing feedback to maintain constant bias voltage, and may include an SiGe absorption region to provide extended long wavelength response or lower avalanche voltage. Non-avalanche photodiodes may also be used.

Abstract: An optical transistor is disclosed that provides a fast switching time, an amplified gain, and isolation. The optical transistor receives a small optical input signal at an optical base port, generates an amplified replica at an optical emitter port, and generates an inverted replica on a vertical light at an collector port. One embodiment of the optical transistor is implemented with a vertical lasing semiconductor optical amplifiers (VLSOA), wherein the ballast light is used a signal for the collector port.

Abstract: Disclosed is a PIN photodiode used for a light-receiving element for optical communication. The PIN photodiode comprises a gate electrode structure consisting of a gate insulation layer and a gate electrode pad which prevent a bonding layer from being excessively depleted in the lateral direction at the time of applying a negative electric voltage to an electrode that is in contact with the bonding layer. The PIN photodiode allows the control of the electrostatic capacitance of the element by controlling the depletion level of the bonding layer in the lateral direction using the gate electrode pad. Therefore, it is possible to suppress the increase of the electrostatic capacitance and to achieve a high-speed operating property.

Abstract: A photodetector includes an optical absorption layer having a thickness d optimized with regard to a voltage applied across the optical absorption layer such that there occurs an increase of optical absorption coefficient at the wavelength of 1580 nm or longer.

Abstract: A light-receiving element array is provided in which the degradation of characteristic thereof due to the crosstalk may be prevented. An n-InP layer, an i-InGaAs layer, and an n-InP layer are stacked on an n-InP substrate. Zn is diffused into the topmost n-InP layer to form a p-type diffused region, resulting in a pin-photodiode. A passivation layer is deposited on the structure to a thickness such that a nonreflective condition is satisfied. On the passivation film, a light-shielding film is provided so as to cover the area between light-receiving elements.

Abstract: In one aspect the invention relates to a high bandwidth shallow mesa semiconductor photodiode responsive to incident electromagnetic radiation. The photodiode includes an absorption narrow bandgap layer, a wide bandgap layer disposed substantially adjacent to the absorption layer, a first doped layer having a first conductivity type disposed substantially adjacent to the wide bandgap layer, and a passivation region disposed substantially adjacent to the wide bandgap layer and the first doped layer.

Abstract: Reducing a dark current in a semiconductor photodetector provided with a second mesa including an regrown layer around a first mesa. An n-type buffer layer, a n-type multiplication layer, a p-type field control layer, a p-type absorption layer, a cap layer made of p-type InAlAs crystal, and a p-type contact layer 107 are made to grow on a main surface of a n-type substrate. Thereafter the p-type contact layer, the p-type cap layer, the p-type absorption layer and the p-type field control layer are patterned to form a first mesa. Next, after making a p-type regrown layer selectively grow around the first mesa or by forming a groove in the regrow layer located in a vicinity of the p-type cap type during a step of the selective growth, the p-type cap layer containing Al and the regrow layer are separated owing to the groove such that no current path is formed between both layers.

Abstract: An avalanche photodiode (APD) includes an absorption layer above the multiplication layer, where the thickness of the multiplication layer is defined through a growth process. The APD can also have a third-terminal, or peripheral ring terminal, for collecting charge carriers generated outside the optically-active region of the device. Undesirable dark current can thus be better managed during the life of the device. The three-terminal design may also be utilized in other photodetectors, including PIN diodes.

Abstract: An infrared photodetector structure with voltage-tunable and -switchable photoresponses constructed of superlattices and blocking barriers. The photoresponses of the double-superlattice structure are also insensitive to the operating temperature changes. By using GaAs/AlxGa1-xAs system, the feasibility of this idea is verified. In the embodiment, the photoresponses can be switched between 6˜8.5 and 7.5˜12 m by the bias polarity and are also tunable by the bias magnitude in each detection wavelength range. In addition, the photoresponses are insensitive to operating temperatures ranging from 20 to 80 K. For the SLIP with few periods, the responsivity may be higher than the one with many periods and the operational temperature is higher. These results show the invention can be useful in the design of multicolor imaging systems.

Abstract: A sequential mesa type avalanche photodiode (APD) comprises a semiconductor substrate and a sequential mesa portion formed on the substrate. In the sequential mesa portion, a plurality of semiconductor layers, including a light absorbing layer and a multiplying layer, are laminated by epitaxial growth. In the plurality of semiconductor layers, a pair of semiconductor layers forming a pn junction is included. The carrier density of a semiconductor layer which is near to the substrate among the pair of semiconductor layers is larger than the carrier density of a semiconductor layer which is far from the substrate among the pair of semiconductor layers. In the APD, light-receiving current based on movement of electrons and positive holes generated in the sequential mesa portion when light is incident from the substrate toward the light absorbing layer is larger at a central portion than at a peripheral portion of the sequential mesa portion.

Abstract: The present invention relates to an impact ionisation avalanche transit time (IMPATT) diode device comprising an avalanche region and a drift region, wherein at least one narrow bandgap region, with a bandgap narrower than the bandgap in the avalanche region, is located adjacent to or within the avalanche region in order to generate within the narrow bandgap region a tunnel current which is injected into the avalanche region. This improves the predictability with which a current can be injected into the avalanche region and enables a relatively narrow pulse of current to be injected into the avalanche region in order to enable a relatively noise free avalanche multiplication. The narrow bandgap region may be located between a heavily doped contact region and the avalanche region and is preferably arranged to generate a tunnel current at the peak reverse bias applied to the diode.

Abstract: In one aspect the invention relates to a high bandwidth shallow mesa semiconductor photodiode responsive to incident electromagnetic radiation. The photodiode includes an absorption narrow bandgap layer, a wide bandgap layer disposed substantially adjacent to the absorption layer, a first doped layer having a first conductivity type disposed substantially adjacent to the wide bandgap layer, and a passivation region disposed substantially adjacent to the wide bandgap layer and the first doped layer.

Abstract: A PIN photodetector includes reduced parasitic capacitance and is suitable for high-speed applications. Metal interconnect leads are coupled to the photodetector and extend over electrically insulating regions which reduce or eliminate parasitic capacitance. The electrically insulating regions may be formed by a deep proton implantation process which introduces impurities into the N-type layer, P-type layer and intrinsic layer in portions of the inactive area according to one embodiment. In another embodiment, the electrically insulating regions may be formed by removing parts of the film stack that includes N-type layer, P-type layer and intrinsic layer, from portions of the inactive area, introducing impurities and optionally adding a dielectric material. The PIN photodetector may take on the shape of a mesa to provide contact to each of the upper and lower electrodes.

Abstract: An avalanche photodiode charge-carrier multiplication region comprises a first region fabricated from a first material having a first impact ionization threshold and a second region joined to the first region at an interface and fabricated from a second material having a second impact ionization threshold lower than the first impact ionization threshold. The first region includes, in the presence of an applied reverse-bias, first and second oppositely charged layers to establish an elevated, localized electric field within a sub-region of the first region. The first and second charged layers are arranged such that preferred charge carriers are accelerated by the localized electric field just prior to being injected into the second material where they impact ionize at predetermined statistical rate.

Abstract: An Indium/Gallium/Arsenide (InGaAs) detector having avalanche photodiodes (APD's) and p-i-n photodiodes on a single chip is provided. A method of fabricating the InGaAs device is also provided. The bias on the APD and p-i-n photodiodes are separately controlled.

Abstract: There is provided a semiconductor photodetector which comprises (i)an InP substrate(1), (ii)an optical waveguide(5) having an N-type semiconductor layer(32) formed on the InP substrate(1), an optical waveguide core layer(3) formed on a partial area of the N-type semiconductor layer(32), and an upper cladding layer(4) formed on the optical waveguide core layer(3), and (iii)an avalanche photodiode(17) constructed by forming a photo absorbing layer(33), a heterobarrier relaxing layer(34), an underlying layer(14a) of a N-type field dropping layer(35), an overlying layer(14b) of the N-type field dropping layer(35), a carrier multiplying layer(36), and a P-type semiconductor layer(37) in sequence on another area of the N-type semiconductor layer(32), and coupled to the optical waveguide(5), wherein a side surface of the underlying layer(14a) of the N-type field dropping layer(35) comes into contact with a side surface of the optical waveguide core layer(3), and a part of the overlying layer(14b) of the N-type field

Abstract: The speed at which optical networking devices operate is increased with the present invention with integrated circuits that provide both optical and electronic functions. The present invention provides highly integrated p-i-n or p-i-n-i-p photodetectors and heterojunction bipolar transistors for amplifying photodetector signals formed from a single semiconductor layer stack. The techniques are applicable for the integration of all InP-based and GaAs-based single-heterojunction bipolar transistors and double-heterojunction bipolar transistors. The photodetectors and transistors are formed from common layers, allowing them to be manufactured simultaneously during a processing of the stack. Integrating these components on a single circuit has the potential to greatly increase the speed (in excess of 40 Gb/s) and to decrease the cost of high-speed networking components through the development of compact optical circuits for optical networking.