WO2008075542A1 - フォトダイオード、光通信デバイスおよび光インタコネクションモジュール - Google Patents
フォトダイオード、光通信デバイスおよび光インタコネクションモジュール Download PDFInfo
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- WO2008075542A1 WO2008075542A1 PCT/JP2007/072904 JP2007072904W WO2008075542A1 WO 2008075542 A1 WO2008075542 A1 WO 2008075542A1 JP 2007072904 W JP2007072904 W JP 2007072904W WO 2008075542 A1 WO2008075542 A1 WO 2008075542A1
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Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/08—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors
- H01L31/10—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors characterised by potential barriers, e.g. phototransistors
- H01L31/101—Devices sensitive to infrared, visible or ultraviolet radiation
- H01L31/102—Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier
- H01L31/108—Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier the potential barrier being of the Schottky type
- H01L31/1085—Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier the potential barrier being of the Schottky type the devices being of the Metal-Semiconductor-Metal [MSM] Schottky barrier type
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y20/00—Nanooptics, e.g. quantum optics or photonic crystals
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- G—PHYSICS
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- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
- G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
- G02B6/122—Basic optical elements, e.g. light-guiding paths
- G02B6/1226—Basic optical elements, e.g. light-guiding paths involving surface plasmon interaction
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/08—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors
- H01L31/10—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors characterised by potential barriers, e.g. phototransistors
- H01L31/101—Devices sensitive to infrared, visible or ultraviolet radiation
- H01L31/102—Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier
- H01L31/105—Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier the potential barrier being of the PIN type
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/02—Details
- H01L31/0224—Electrodes
Definitions
- the present invention relates to a photodiode.
- the present invention relates to a photodiode that converts light (including infrared light) signals necessary for information processing and communication fields into electric signals at high speed.
- the present invention also relates to an optical communication device and an optical interconnection module using the photodiode.
- Monolithically integrating photodetectors is very attractive in terms of cost and yield.
- Silicon photodiodes monolithically integrated on the same chip as the CMOS circuits, ie silicon photodiodes, are an attractive alternative to hybrid light receivers (eg, InGaAs photodiodes bonded to CMOS circuits or GaAs circuits). It is an alternative.
- Monolithically integrated receivers can be manufactured using standard silicon processes and are expected to be cheaper to manufacture than hybrid designs.
- the typical one is a pin type photodiode.
- the pin type photodiode has a structure in which an i layer of an intrinsic semiconductor is sandwiched between ap layer of a p type semiconductor and an n layer of an n type semiconductor. Then, when a reverse bias voltage is applied by a bias power supply, almost the entire high-resistance i layer becomes a charge carrier depletion layer. The photons of the incident light are mainly absorbed in the i-layer to generate electron 'hole pairs.
- the generated electrons and holes respectively drift in opposite directions in the depletion layer by reverse bias voltage to generate current, and are detected as signal voltage by the load resistance.
- a factor that limits the response speed of this photoelectric conversion is a circuit time constant that is determined by the product of the load resistance and the electric capacity formed by the depletion layer. Further, as the factor, the carrier transit time required for electrons and holes to pass through the depletion layer can be mentioned.
- a Schottky type photodiode As a photodiode having a short carrier travel time, there is a Schottky type photodiode. It has a structure in which a semitransparent metal film is in contact with the n layer (or n_ layer) of the semiconductor. One. A Schottky barrier is formed near the interface where the n layer (or n_ layer) and the semitransparent metal film are in contact. In the vicinity of the Schottky barrier, electrons diffuse from the semitransparent metal film to the n layer (or n_ layer) to form a depletion layer. In this state, when incident light is irradiated, electrons are generated in the n layer (or n_ layer). The generated electrons drift in the depletion layer due to the reverse bias voltage. And, it is possible to effectively utilize the light absorption in the element surface layer.
- the pin type photodiode it is necessary for the pin type photodiode to have a sufficient thickness in the i layer, that is, the depletion layer, in order to absorb photons.
- the Schottky type photodiodes can make the depletion layer thinner. Therefore, the Schottky photodiode can shorten the carrier travel time.
- the value of the load resistance is reduced in order to shorten the circuit time constant, the voltage of the reproduction signal that can be taken out drops. Therefore, in order to increase the S / N of the reproduction signal and to reduce the read error, it is necessary to reduce the capacitance of the depletion layer. In particular, if the depletion layer is thinned to shorten the carrier transit time, the electric capacity increases. Therefore, for speeding up, it is necessary to reduce the depletion layer (or the area of the Schottky junction). Although the force is reduced, the reduction of the joint area reduces the utilization efficiency of the signal light. As a result, the S / N of the reproduction signal is degraded.
- MSM metal / semiconductor / metal
- Patent Document 1 a metal / semiconductor / metal (MSM) device (photodetector) in which two electrodes are disposed on the same surface of a semiconductor has been proposed (Patent Document 1).
- This MSM photodetector is a type of Schottky photodiode with a Schottky barrier near two electrodes. That is, part of the light transmitted through the electrode surface is absorbed by the semiconductor layer (semiconductor absorption layer) to generate photocarriers. In such MSM photodetectors, the quantum efficiency is increased. If the semiconductor is made thicker for this purpose, the operating speed decreases because the propagation distance of photo carriers increases. In order to prevent the decrease in the operating speed, the photodetector described in Patent Document 1 is provided with metal electrodes along the periodic unevenness. In this way, incident light efficiently couples with surface plasmons of the metal electrode and propagates into the light detector.
- Patent Document 2 a method of manufacturing a MSM type light receiving device in which a metal film provided on a semiconductor is partially oxidized to form a light transmitting insulating film has been proposed.
- a MSM-type light receiving element uses near-field light generated from the end of a metal film on both sides of a light transmitting insulating pattern (the pattern width is a dimension smaller than the wavelength of transmitted light). Article 3). And, it is described that the response speed of this MSM type light receiving element is increased.
- Patent Document 4 discloses a technique for coupling the incident light with the transmitted light, the reflected light, the surface plasmon polariton and the like by resonance. Further, Patent Document 4 states that the photocarrier force S generated and the coupling between the incident light and the surface plus' are strengthened. However, in these light receiving elements, if the irradiation area of the incident light is reduced to reduce the capacitance of the depletion layer, the intensity of the detection signal decreases and the S / N decreases.
- a photovoltaic device (light using solar energy) is provided with an aperture (or a recess) periodically arranged on one of two electrodes sandwiching a plurality of spherical semiconductors having a pn junction.
- An electromotive force device is proposed (Patent Document 5)! This photovoltaic device utilizes the resonance of the surface plasmon with the incident light. While this patent document 5 describes thinning the depletion layer and shortening the area for speeding up the photoelectric conversion! // ,.
- Patent Document 7 an MSM type light receiving element in which the light absorbing layer has a multilayer film structure in which a photonic band is formed has been proposed. It has been reported that this MSM light receiving element has high light receiving efficiency. However, even in this structure, it has not been realized to reduce the junction area in the MSM junction and to reduce the element capacitance.
- pin type photodiode pin type photodiode using InGaAs
- a micro lens is provided on the back surface of the substrate, and a mirror is provided to reflect light reflected from the back surface again from the back surface.
- Patent Document 8 It has been reported that this photodiode can improve the tolerance of the light coupling alignment with the external light and can reduce the device junction area. Even in this structure, the diameter of the light spot collected by the micro lens is on the order of several tens of meters in this structure, and there is a limit to achieving high frequency response by reducing the element capacity.
- Non-Patent Document 1 SJ Koester, G. Dehlinger, JD Schaub J. O. Chu, QC Ouyang, a. A. A. Grill, "Germanium-on-Insulator Photodetectors, 2nd International Conferencing Group IV Photonics, FB I 2005, (No. 172) Page, Fig. 3)
- Patent Document 1 Japanese Patent Application Laid-Open No. 59-108376 (page 4-16, FIG. 1-3)
- Patent Document 2 Patent No. 2666888 (page 3-4, FIG. 2)
- Patent Document 3 Patent No. 2705757 (Page 6, Fig. 1)
- Patent Document 4 JP-A-10-509806 (page 26-33, FIG. 1)
- Patent Document 5 Japanese Patent Application Laid-Open No. 2002-76410 (Page 6-9, FIG. 1)
- Patent Document 6 Japanese Patent Application Laid-Open No. 2000-171763 (Pages 7-10, FIGS. 10 and 17)
- Patent Document 7 Japanese Patent Application Laid-Open No. 2005-150291 (page 5, FIG. 1)
- Patent Document 8 Japanese Patent Application Laid-Open No. 6-77518 (Page 2, FIGS. 1, 2)
- Metal-Semiconductor Metal (MSM) photodiodes provide planarity and compatibility with silicon LSIs.
- photodetectors using Si are generally slow due to long carrier lifetime (1 to 10 3) and low light absorptivity (10 to 100 / cm). Indicates responsiveness.
- the Schottky barrier photodiode exhibits a high-speed response.
- the metal electrode reduces the effective light receiving area. Therefore, the sensitivity decreases.
- the problem to be solved by the present invention is to provide a device structure that achieves both the light receiving sensitivity of the photodiode and the high speed.
- the subject is a Schottky barrier type photodiode in which a conductive layer is provided on the surface of a semiconductor layer,
- the photodiode is configured to allow light to be incident from the back surface side of the semiconductor layer, and light incident from the back surface side of the semiconductor layer causes surface plasmon resonance around the Schottky junction of the photodiode. It is solved by a photodiode characterized in that a periodic structure is formed. [0027] Moreover, the photodiode is a PIN type photodiode provided on the surface of the semiconductor layer, and the photodiode is configured to allow light to be incident from the back surface side of the semiconductor layer. A conductive layer is provided around the pin junction, and a periodic structure in which light incident from the back surface side of the semiconductor layer causes surface plasmon resonance is configured.
- the problem is solved by the photodiode characterized in that.
- the photodiode is provided with a metal-semiconductor-metal junction arranged at intervals on the surface of the semiconductor layer,
- the photodiode is configured to allow light to enter from the back surface side of the semiconductor layer, and a conductive layer is provided around the metal-semiconductor metal junction of the photodiode, and the light incident from the back surface side of the semiconductor layer Periodic structure in which the emitted light causes surface plasmon resonance
- the problem is solved by the photodiode characterized in that.
- an optical communication device characterized in that the above-mentioned photodiode is provided in the light receiving section.
- the present invention solves an optical interconnection module including the photodiode and an LSI electronic circuit monolithically formed on the Si substrate. Effect of the invention
- FIG. 1 is a cross-sectional view of a photodiode according to a first embodiment.
- FIG. 2 A sectional view of the photodiode according to the second embodiment
- FIG. 3 A sectional view of the photodiode of the third embodiment
- FIG. 4 A sectional view of the photodiode of the fourth embodiment
- FIG. 11 A graph showing the characteristics of the photodiode of the first embodiment
- FIG. 13 A graph showing the characteristics of the photodiode of the second embodiment
- FIG. 14 A graph showing the characteristics of the photodiode of the third embodiment
- FIG. 15 A plan view of the photodiode of the fourth embodiment
- FIG. 16 A graph showing the characteristics of the photodiode of the fourth embodiment
- FIG. 17 A sectional view of the photodiode of the fifth embodiment
- FIG. 18 Cross sectional view of the photodiode according to the sixth embodiment
- FIG. 19 A sectional view of the photodiode of the seventh embodiment
- FIG. 20 A sectional view of the photodiode of the eighth embodiment
- FIG. 21 A schematic view of a transmission light receiving module equipped with a Schottky type photodiode according to the present invention
- FIG. 22 Schematic diagram of the optical interconnect between LSI chips on which the photodiode of the present invention is mounted
- Optical signal output fiber 34 Optical signal input fiber
- the first photodiode according to the present invention is a semiconductor key barrier type photodiode in which a conductive layer is provided on the surface of a semiconductor layer.
- the photodiode is configured to allow light to be incident from the back side of the semiconductor layer.
- a periodic structure in which light incident from the back surface side of the semiconductor layer causes surface plasmon resonance is formed around the Schottky junction of the photodiode !.
- the second photodiode according to the present invention is a p-i n -type photodiode provided on the surface of the semiconductor layer.
- the photodiode is configured such that light can be incident from the back side of the semiconductor layer.
- a conductive layer is provided around the p-i junction of the photodiode, and a periodic structure in which light incident from the back side of the semiconductor layer causes surface plasmon resonance is configured.
- a third photodiode according to the present invention is a photodiode provided with metal-semiconductor semiconductor junctions spaced on the surface of the semiconductor layer.
- the photodiode is configured to allow light to enter from the back surface side of the semiconductor layer.
- a conductive layer is provided around the metal-semiconductor-metal junction of the photodiode, and a periodic structure in which light incident from the back side of the semiconductor layer causes surface plasmon resonance is configured.
- a fourth photodiode according to the present invention is, in particular, configured as follows in the third photodiode.
- the distance between the metal and the semiconductor metal junction disposed on the front surface of the semiconductor layer is equal to or less than ⁇ / ⁇ (where ⁇ is the wavelength of light incident from the back surface side of the semiconductor layer and ⁇ is the refractive index of light in the semiconductor layer) .
- the metal layer is formed by laminating a metal layer which forms a Schottky junction with the semiconductor, and a layer made of a conductive material capable of inducing surface plasmon. Alternatively, the metal layer can form a Si key-junction with the semiconductor and can induce surface plasmons. Metal layer.
- the fifth photodiode according to the present invention is, in particular, configured as follows in the third or fourth photodiode.
- the metal-semiconductor-metal junction at least one of the opposing metal-semiconductor junctions is a Schottky barrier junction.
- a sixth photodiode according to the present invention is particularly configured as follows in any of the first to fifth photodiodes.
- the periodic structure causing the surface plasmon resonance is a structure in which a conductive layer capable of inducing surface plasmon is laminated on the surface of the semiconductor layer in which the unevenness is formed.
- the seventh photodiode according to the present invention is particularly configured as follows in any of the first to sixth photodiodes.
- the periodic structure causing surface plasmon resonance is a structure in which a conductive layer capable of inducing surface plasmon is laminated on the surface of the dielectric layer on which the unevenness is formed.
- the eighth photodiode according to the present invention is particularly configured as follows in any of the first to seventh photodiodes.
- the surface plasmon resonance is not generated on the outside of the periodic structure that generates surface plasmon resonance! /,
- the periodic structure is configured.
- a ninth photodiode according to the present invention is particularly configured as follows in any one of the first to eighth photodiodes.
- a stepped structure for reflecting surface plasmons is formed outside the periodic structure that causes surface plasmon resonance.
- the tenth photodiode according to the present invention is particularly configured as follows in the ninth photodiode.
- the step structure is ⁇ / ((where ⁇ is adjacent to the conductive film)
- the eleventh photodiode according to the present invention is particularly configured as follows in the ninth or tenth photodiode.
- the step structure has ⁇ / ((where ⁇ is
- the twelfth photodiode according to the present invention is particularly configured as follows in any one of the ninth to eleventh photodiodes.
- the step structure has a shape in which holes having a diameter equal to or smaller than the wavelength of incident light provided in the conductive material are arranged.
- the thirteenth photodiode according to the present invention is particularly configured as follows in any of the ninth to twelfth photodiodes.
- the step structure has a shape in which slits having a width equal to or smaller than the wavelength of incident light provided in the conductive material are arranged.
- the fourteenth photodiode according to the present invention is particularly configured as follows in any of the ninth to thirteenth photodiodes.
- the conductive layer is made of at least one metal (or alloy) selected from the group of Al, Ag, Au and Cu.
- the fifteenth photodiode according to the present invention in any one of the first to fourteenth photodiodes, is particularly configured as follows.
- the junction area in the photodiode is less than 100 square meters.
- the sixteenth photodiode according to the present invention is especially configured as follows in any of the first to fourteenth photodiodes.
- the junction area in the photodiode is less than 10 square meters.
- the seventeenth photodiode according to the present invention is especially configured as follows in any of the first to fourteenth photodiodes.
- the junction area in the photodiode is less than one square meter.
- the eighteenth photodiode according to the present invention is particularly configured as follows in any one of the first to seventeenth photodiodes.
- the thickness of the semiconductor absorption layer in the photodiode is 1 m or less.
- the nineteenth photodiode according to the present invention is particularly configured as follows in any one of the first to seventeenth photodiodes.
- the thickness of the semiconductor absorption layer in the photodiode is 200 nm or less.
- the twentieth photodiode according to the present invention is particularly configured as follows in any of the first to nineteenth photodiodes.
- the semiconductor absorption layer in the photodiode is Si, SixGel-x (where X is a positive number less than 1), Ge, GaN, GaAs, GalnAs,
- the twenty first photodiode according to the present invention is particularly configured as follows in any of the above first to twentieth photodiodes.
- the semiconductor absorption layer in the photodiode is made of at least one selected from the group of Ge, SixGel-x (where x is a positive number less than 1). And, a layer composed of an alloy of Ni and Ge is provided between the semiconductor absorption layer and the conductive layer.
- the twenty-second photodiode according to the present invention is particularly configured as follows in any of the first to twenty-first photodiodes.
- a photodiode is configured on a semiconductor optical waveguide.
- the twenty-third photodiode according to the present invention is particularly configured as follows in any of the first to twenty-first photodiodes.
- the photodiode is configured to receive light reflected by the mirror from the optical waveguide formed on the substrate side.
- the twenty-fourth photodiode according to the present invention is particularly configured as follows in any of the first to twenty-third photodiodes.
- the substrate of the photodiode is made of a material transparent to incident light.
- the first photodiode of the present invention is a Schottky barrier wall photodiode having a conductive film on the surface of a semiconductor layer. Then, light can be incident from the back side of the semiconductor layer.
- the periphery of the Schottky junction has a periodic structure for causing light incident from the back surface side of the semiconductor layer to cause surface plasmon resonance. This increases the light coupling efficiency with light incident from the back side of the semiconductor layer.
- This structure is shown in FIG. That is, as shown in FIG. 1, a conductive film 2 is provided on the surface of the semiconductor layer (semiconductor absorption layer) 1. This constitutes a Schottky junction.
- a periodic structure in which light incident from the back surface side (support substrate 8 side) of the semiconductor layer (semiconductor absorption layer) 1 causes surface plasmon resonance around the Schottky junction, that is, a periodic uneven structure 9 is configured.
- the periphery of the semiconductor absorption layer 1 was made to be a semiconductor layer (or dielectric layer) having a refractive index lower than that of the semiconductor absorption layer 1. This refractive index difference confines light. That is, the light confinement effect allows the light power incident on the semiconductor absorption layer 1 to be localized to the minute Si-Key junction region. As a result, efficient photoelectric conversion is achieved in a semiconductor absorption layer of very small volume.
- FIG. 2 shows that a Schottky contact layer (semiconductor layer for Schottky junction (or a metal layer for realizing sufficient Schottky barrier energy)) 10 is provided on the surface of the semiconductor layer (semiconductor absorption layer) 1, In the photodiode in which the conductive film 2 is provided on the Schottky contact layer 10
- a Schottky contact layer semiconductor layer for Schottky junction (or a metal layer for realizing sufficient Schottky barrier energy)
- periodic concave / convex structure (semiconductor layer (semiconductor absorption layer) 1) around the Schottky junction is for light incident from the back surface side to cause surface plasmon resonance.
- Periodic structure 9 is configured!
- the second photodiode of the present invention is a photodiode in which a pn junction is provided on the surface of a semiconductor layer. And, it is configured such that light can be incident from the back side of the semiconductor layer.
- a conductive layer is provided around the p ⁇ i ⁇ n junction of the photodiode, and a periodic structure in which light incident from the back side of the semiconductor layer causes surface plasmon resonance.
- This periodic structure 9 is, for example, periodic for light incident from the back surface side (n + electrode layer 12: support substrate 8 side) of the semiconductor layer (semiconductor absorption layer: i layer) 1 to cause surface plasmon resonance. Uneven structure. This increases the light coupling efficiency with light incident from the back side of the semiconductor layer.
- This structure is shown in FIG. That is, as shown in FIG. 3, the conductive film 2 is provided on the surface of the semiconductor layer (semiconductor absorption layer: i layer) 1. And The light incident from the back side of the carrier substrate 8 is converted to surface plasmons by the concavo-convex structure 9 provided around the pin junction, and is collected at the pin junction at the center. Ru.
- the periphery of the semiconductor absorption layer 1 is preferably a semiconductor layer (or dielectric layer) having a refractive index lower than that of the semiconductor absorption layer 1.
- This refractive index difference confines light. That is, the light confinement effect allows the incident light power to be localized at the central pin junction. Thereby, efficient photoelectric conversion is achieved in the semiconductor absorption layer 1 of very small volume.
- the conductive film 2 can be used as an antenna and an electrode for plasmon resonance.
- the electrode layer 11 can be constructed using a semiconductor having a band gap larger than the light energy received by the semiconductor absorption layer (i layer) 1, the electrode The light absorption loss in the layer 11 (12) can be reduced. As a result, the photoelectric conversion efficiency can be further improved.
- the third photodiode of the present invention is a photodiode provided with a metal-semiconductor metal (MSM) junction spaced apart on the surface of the semiconductor layer. And, it is configured such that light can be incident from the back side of the semiconductor layer.
- a conductive layer is provided around the MSM junction, and a periodic structure in which light incident from the back surface side of the semiconductor layer causes surface plasmon resonance is configured. This increases the light coupling efficiency with light incident from the back side of the semiconductor layer.
- This structure is shown in FIG. That is, the MSM electrode 13 is provided on the surface of the semiconductor layer (semiconductor absorption layer) 1.
- a conductive film 2 is provided around the MSM electrode 13. And, periodic uneven structure (periodic structure for light incident from the back surface side of the semiconductor layer (semiconductor absorption layer) 1 (support substrate 8 side) to cause surface plasmon resonance around the MSM electrode 13) 9 Is configured!
- the metal electrode formed on the semiconductor surface blocks the light receiving surface of the photodiode, thereby reducing the light receiving sensitivity. Even in the case of providing an electrode spacing that causes surface plasmon resonance, the region where the optical electric field strength is strong is in the region outside the semiconductor. Therefore, efficient photo carrier generation can not be performed.
- the semiconductor absorption layer 1 is a semiconductor layer (or dielectric layer) having a refractive index lower than that of the semiconductor absorption layer 1. This refractive index difference confines light. This results in very efficient photoelectric conversion.
- a depletion layer region of 200 nm or more is formed even at zero bias at a doping concentration of 1 ⁇ 10 15 to 1 ⁇ 10 16 cm ⁇ 3. Be done. Therefore, by reducing the distance between the electrodes, high speed and high sensitivity photodiode operation can be performed even at a low bias voltage.
- the drift time between electrodes of photocarriers is several ps even in the case of a semiconductor material (for example, Si) having a mobility of 10 7 cm / s It is considered to be.
- the drift time can be made to be 20 ps or less.
- the distance between MSM electrodes is about 100 nm
- the junction capacitance is less than 10 fF.
- the junction capacitance is less than 100 fF. That is, assuming that the load resistance is 50 ⁇ , the circuit time constant is lps in the former case and 10 ps in the latter case. Therefore, very fast response is realized.
- FIG. 5 is an example showing a surface plasmon resonance structure which enables light to be confined to a size equal to or smaller than the light wavelength when light is incident from the back side of the light absorption layer. That is, the periodic uneven structure 9 is provided around the center minute Schottky contact portion 18. This makes it possible to couple incident light with surface plasmons induced on the surface of the conductive film (metal film) 2 and to condense light energy on the Schottky contact portion as a surface plasmon.
- the periphery of the semiconductor light absorption layer 1 disposed in the Schottky contact portion is a semiconductor layer (or dielectric layer) having a refractive index lower than that of the semiconductor absorption layer 1. This refractive index difference confines light. That is, due to the light confinement effect, the light power incident on the semiconductor absorption layer 1 can be localized in the minute Schottky junction region. As a result, efficient photoelectric conversion is achieved in a semiconductor absorption layer of very small volume.
- FIG. 6 shows an example of a structure in which a forbidden band grating 14 which does not cause plasmon resonance is formed on the outside of the surface plasmon resonance structure (concave and convex structure 9). Due to the periodic uneven structure 9 formed in the conductive film 2, light incident from the back side of the semiconductor absorption layer 1 Are converted to surface plasmons. Although there is a force, the converted surface plasmon includes a component collected on the central portion (Schottky contact portion 18) and a component propagating to the outside of the light irradiation area. The component propagating to the outside causes a loss in improving the light receiving sensitivity.
- a structure 14 in which the periodic asperity structure 9 is larger than the light irradiation area and in which the propagation mode of surface plasmon does not exist is provided outside the periodic asperity structure 9.
- a forbidden band grating 14 is realized by forming a grating structure having a period of about 1/2 of the grating period obtained from the dispersion relation of surface plasmons.
- FIGS. 7, 8, 9 and 10 have periods for the same purpose as arranging the forbidden band grating 14 when causing light to be incident from the back side of the semiconductor absorption layer 1 to cause plasmon resonance.
- An example of the structure (projection shape 15, groove shape 16, slit array 17, and through hole 17) of reflecting the surface plasmon propagating to the outside of the typical unevenness is shown. That is, a protrusion shape 15 higher than ⁇ / ⁇ ( ⁇ : refractive index of induced d d collector layer, ⁇ : wavelength of light), and a groove shape 16 d deeper than ⁇ / ⁇
- a periodic slit 17 penetrating the conductive film 2 or a minute open lower ray 17 having a wavelength equal to or less than the wavelength is disposed outside the periodic asperity 9 that causes surface plasmon resonance.
- the same effect as the forbidden band grating 14 can be realized.
- the minute open array 17 having a wavelength or less at a period of about 1/2 of the plasmon resonance period radially from the central portion reflection of surface plasmon can be effectively generated.
- the phase relationship between the surface plasmon to be reflected and the resonance mode is important. For example, by matching the resonance mode with the reflection phase, maximum light receiving sensitivity can be obtained.
- ⁇ and ⁇ are the induction m d of the metal generating the surface plasmon and the dielectric in contact therewith
- the propagation length of the surface plasmon is represented by the following equation 2.
- the complex dielectric constant ⁇ of the metal is expressed as ⁇ ′ + ⁇ ′ ′.
- the optical loss of surface plasmons largely depends on the ratio of the imaginary part of the dielectric constant of the metal film to the square of the real part. Therefore, the conductive layer of the present invention is desirably made of at least one metal (or an alloy selected from these) selected from Al, Ag, Au and Cu. Also, from the viewpoint of reducing the propagation loss of surface plasmons, it is very important to reduce the random unevenness of the metal surface. Therefore, it is preferable to provide an underlayer such as Ta, Cr, Ti, or Zr. Alternatively, even when a small amount of an element such as Nb is added to form an alloy, it is effective.
- the intensity distribution of near-field light due to surface plasmons is affected by the periodic uneven structure, the refractive index of the adjacent dielectric layer, the arrangement of the MSM electrode, and the refractive index and absorption coefficient of the semiconductor absorption layer. Change.
- the structure of the present invention which localizes light energy in a very small area of a semiconductor, it becomes possible to generate electron-hole pairs (photocarriers). Therefore, efficient photocarrier formation and local photocarrier travel are realized by matching the depletion region formed in the semiconductor absorption layer with the Schottky junction and the photocarrier generation region by the near field. it can. As a result, a photodiode having high quantum efficiency and fast response characteristics can be obtained.
- a Schottky junction or pin junction area for generating and sweeping photocarriers can be made smaller than 10 squares ⁇ .
- the junction capacitance can be made extremely small. Therefore, the circuit time constant for operating the photodiode at high frequency can be reduced to several picoseconds or less, and high frequency operation of several tens of GHz or more can be realized.
- an optical waveguide in which the difference in refractive index between the core and the cladding is 5% or more.
- a channel-type optical waveguide has a structure in which the core is surrounded by a medium having a smaller refractive index than the core. ing. Then, due to the difference in refractive index between the core and the cladding layer, light propagates while repeating total reflection. In this case, if the difference in refractive index between the core and the cladding layer is large, light is strongly confined to the core. Thus, even if the waveguide is sharply bent with a small curvature, light is guided along it.
- the refractive index difference is 5% or more, it is possible to realize a light spot diameter of 10 m or less. Furthermore, when the difference in refractive index between the core and the cladding is about 10 to 40%, it is possible to realize a light spot diameter of a size equal to or less than the wavelength.
- a waveguide core with a cross-sectional size of approximately 0 ⁇ S ⁇ m X O. 3 m is made of Si (refractive index is approximately 3 ⁇ 4), and the circumference (cladding layer) of this waveguide core is SiO (refractive index In the case of a structure covered by about 1.5)
- the mode size of light is reduced to a size substantially equal to that of the waveguide core.
- the wavelength of light to be guided is about 850 nm
- a waveguide loss is generated due to light absorption. Therefore, when the waveguide core is made of SiO N or the like, which exhibits negligible light transmission characteristics over a wide wavelength range, and the cladding is covered with SiO clad, the refractive index difference is
- the light spot diameter is about 1 to 4 Hm, because the light confinement becomes weaker as compared with the case of using the semiconductor core (Si).
- the wavelength range of light for which the present invention is effective covers a wide wavelength range including visible light, near infrared light, and infrared light.
- the refractive index of the metal periodic structure that induces surface plasmon resonance By adjusting the refractive index of the metal periodic structure that induces surface plasmon resonance, the laminated structure of the semiconductor absorption layer that efficiently confines and transmits light, and the dielectric layer adjacent to the semiconductor absorption layer, A high-speed photodetector that efficiently generates photocarriers and obtains electrical signals can be obtained.
- FIG. 1 is a cross-sectional view of a Si Schottky type photodiode according to a first embodiment of the present invention.
- the Schottky photodiode of the present invention has a surface such as SOI (Silicon-on-Insulator).
- a metal semiconductor Schottky junction is provided on a part of the insulated semiconductor absorption layer 1.
- a conductive film 2 for producing surface plasmons is formed on the periphery of this Schottky junction. Then, around the Schottky junction and on the lower surface side of the laminated conductive film 2, the light having entered the periodic uneven structure (the back surface side of the semiconductor absorption layer 1 (support substrate 8 side) is A periodic uneven structure 9 for generating surface plasmon resonance is configured.
- FIG. 1 Silicon-on-Insulator
- reference numeral 3 denotes a lower electrode layer of the semiconductor absorption layer 1
- reference numeral 4 denotes a buried oxide layer provided on a support substrate 8.
- 5 is a load resistance and 6 is a bias power supply.
- An oxide film 7 is provided on the buried oxide layer 4, and a conductive film 2 is provided on the oxide film 7.
- the conductive film 2 provided to induce surface plasmons is a metal such as Al, Ag, Au, or Cu.
- a base film made of a metal such as Cr, Ta or Ni may be provided.
- an n + Si layer in which the dopant concentration of P or the like is 1 ⁇ 10 2 ° cm ⁇ 3 or higher can be used as a substrate.
- the n_Si layer which is the semiconductor absorption layer (light absorption layer) 1
- the dopant concentration of the light absorption layer becomes high due to the thermal diffusion of the dopant element.
- the depletion voltage increases, and the thickness of the depletion layer when the Schottky junction is formed decreases. That is, it becomes difficult to drive at high speed with low voltage.
- n-S leak semiconductor absorption layer (light absorption layer) 1 on the n + Si layer 23
- a technique of epitaxial growth at a low temperature of 600 ° C. or less is required.
- the Si semiconductor supporting substrate 8 is thinned to about 50 to 100 m by CMP (chemical mechanical polishing) or the like. Further, the support substrate 8 on the back surface of the photodiode is dissolved and removed with a mixed solution of hydrofluoric acid and nitric acid, to form a light incident window having a diameter of about 10 to 50 ⁇ m.
- the light incident from the back surface side of the support substrate 8 is converted into surface plasmons by the periodic concavo-convex structure 9 that generates surface plasmon resonance, and is collected at the Schottky junction in the center.
- a semiconductor layer having a refractive index lower than that of the semiconductor absorption layer 1 Alternatively, it is composed of a dielectric layer (oxide film 7)). Therefore, the light power incident on the semiconductor absorption layer 1 is localized in a minute Schottky junction region due to the confinement effect due to the refractive index difference. Thus, efficient photoelectric conversion is achieved in a semiconductor absorption layer of very small volume.
- FIG. 11 is a graph showing the characteristics of the photodiode when light is irradiated around the Schottky junction. That is, in a photodiode formed by arranging an Ag electrode of 120 nm thickness on the surface of a Si semiconductor with a diameter of 200 nm, periodic structure causing plasmon resonance (for example, calculation of electromagnetic field by finite difference time domain method) The sensitivity characteristics are compared in the case of forming the 560 nm period, 50 nm high uneven structure) and the case where there is no periodic uneven structure.
- laser light (wavelength: 850 nm, intensity: lmW) was vertically incident from the back side of the substrate 8 to observe the photocurrent. It can be understood from FIG. 11 that when the periodic concavo-convex structure 9 causing the plasmon resonance is formed, a photocurrant larger by two digits or more is obtained. The quantum efficiency at this time was about 50%.
- FIG. 12 is a cross-sectional view showing a method of manufacturing the photodiode of the present example.
- the n-type doped SOI substrate shown in FIG. 12 (a) is used.
- a semiconductor absorption layer 1 having a thickness of about 20 Onm was epitaxially grown thereon.
- the resistivity of the semiconductor absorption layer 1 is about 1 to 10 ⁇ ′cm, and the doping concentration is about 1 ⁇ 10 15 to 1 ⁇ 10 16 cm o
- the n-type semiconductor absorption layer 1 was patterned as shown in FIG. 12 (b) to define the junction size. That is, patterning was performed by reactive etching using a silicon nitride SiN film as a mask. A mixed gas of CF 4 gas and SF gas was used as the reaction raw gas. And
- the SiN film as shown in FIG. 12 (c) was removed by placing it in hot phosphoric acid at about 130 ° C. for about 1 hour. At this time, a relatively flat surface can be obtained by optimizing the mesa shape and the thermal oxidation process. Further, by applying a CMP process, the one having a flatness of several nm was obtained. Now, a metal layer (conductive film) for forming a Schottky junction is formed on the surface of the mesa shape. At this time, a periodic groove pattern (concave and convex pattern 9) was formed on the surface of the Si oxide film 7 around the semiconductor mesa structure by reactive etching as shown in FIG. 12 (d).
- the conductive film 2 is provided by depositing the alloy having the metal element as a constituent element.
- FIG. 2 is a cross-sectional view of a Ge Schottky type photodiode showing a second embodiment of the present invention.
- the Schottky photodiode of the present invention has a metal-semiconductor Schottky junction formed on a part of the semiconductor absorption layer 1 whose surface is insulated, such as SOI (Silicon-on-Insulator). Since the Ge layer has a lattice mismatch with the Si layer, a suitable buffer layer such as Si 2 Ge was formed to about 10 nm by gas source MBE on the SOI layer with a thickness of 100 nm or less. Buffer
- n-Ge layer was grown on the layer to form a high-quality Ge semiconductor absorption layer 1 with a low threading transition density.
- a Ni underlayer is deposited by vapor deposition or the like.
- 2 is a conductive film
- 3 is a lower electrode layer of the semiconductor absorption layer 1.
- 5 is a load resistance and 6 is a bias power supply.
- An oxide film 7 is provided on the support substrate 8 and a conductive film 2 is provided on the oxide film 7.
- a conductive film 2 for generating surface plasmons is laminated and formed around the Schottky junction.
- a periodic concavo-convex structure 9 is formed so that light incident from the back surface side (support substrate 8 side) of the semiconductor absorption layer 1 causes surface plasmon resonance.
- the conductive film 2 provided to induce surface plasmons is a metal such as Al, Ag, Au, or Cu.
- the underlayer provided to form the Schottky junction may be made of Cr or Ta.
- the lower electrode layer 3 is formed by doping P (phosphorus) in advance to the SOI layer which is a substrate of the Ge growth layer, and has sufficient conductivity.
- Si semiconductor support since light is incident from the back surface side of the support substrate 8, when light having a wavelength of 1 rn or less, which is affected by light absorption of Si, is incident, as in the first embodiment, Si semiconductor support
- the substrate 8 is thinned to about 50 to 100 m by CMP or the like. Then, using a mixed solution of hydrofluoric acid and nitric acid, the supporting substrate 8 on the back surface of the photodiode is dissolved and removed to form a light incident window having a diameter of about 10 to 50 111.
- the light incident from the back surface side of the substrate 8 is converted into surface plasmons by the periodic concave-convex structure 9 that generates surface plasmon resonance, and is collected at the Schottky junction in the center.
- the periphery of the semiconductor absorption layer 1 is formed of a semiconductor layer (or a dielectric layer (oxide film 7)) having a refractive index lower than that of the semiconductor absorption layer 1. Therefore, the optical power incident on the semiconductor absorption layer 1 is localized in the minute Schottky junction region due to the confinement effect due to the refractive index difference. This achieves efficient photoelectric conversion in a semiconductor absorption layer of very small volume.
- FIG. 13 is a graph showing the characteristics of the photodiode when light is irradiated around the Schottky junction. That is, in a photodiode formed by arranging an Ag electrode of 120 nm in thickness on the surface of a Ge semiconductor with a diameter of 200 nm, periodic structure causing plasmon resonance (for example, calculation of electromagnetic field by finite difference time domain method) The sensitivity characteristics are compared in the case of forming the 560 nm period, 50 nm high uneven structure) and the case where there is no periodic uneven structure.
- laser light (wavelength: 850 nm, intensity: lmW) was vertically incident from the back side of the substrate 8 to observe the photocurrent. It can be understood from FIG. 13 that when the periodic uneven structure 9 causing the plasmon resonance is formed, a photocurrant larger by two digits or more is obtained. The quantum efficiency at this time was about 80%.
- the Si support substrate 8 can be treated as a transparent substrate. Therefore, even if the processing process such as removal of the support substrate is not performed, the quantum efficiency is about 60% and sufficient light receiving sensitivity can be obtained only by making the back surface of the substrate a mirror surface.
- FIG. 3 is a cross-sectional view of a pin photodiode according to a third embodiment of the present invention.
- the p-in type photodiode of the present invention is formed by depositing a portion of the semiconductor absorption layer 1 whose surface is insulated such as SOI (Silicon-on-Insulator) by CVD (Chemical Vapor D marking) or the like. It has a formed structure.
- a conductive film 2 for generating surface plasmons is laminated and formed around the pin junction.
- a periodic concavo-convex structure 9 is formed in order for light incident from the back surface side (support substrate 8 side) to generate surface plasmon resonance.
- 4 is a buried oxide layer provided on the support substrate 8
- 5 is a load resistance
- 6 is a bias power supply.
- An oxide film 7 is provided on the buried oxide layer 4
- a conductive film 2 is provided on the oxide film 7.
- a conductive film 2 for generating surface plasmons is laminated on the p + electrode layer 11 on the semiconductor absorption layer 1. Therefore, the conductive film 2 and the p + electrode layer 11 are electrically connected.
- the conductive film 2 provided to induce surface plasmons is made of a metal such as Al, Ag, Au or Cu (or an alloy containing at least one of the metals as an essential constituent element).
- FIG. 14 is a graph showing the characteristics of the photodiode when light is irradiated around the pin junction. That is, in a photodiode formed by arranging a 120 nm thick Ag electrode on a Si semiconductor surface with a diameter of 200 nm, a periodic structure causing plasmon resonance (for example, 560 nm determined by calculating an electromagnetic field by a finite difference time domain method) The sensitivity characteristics are compared in the case where the uneven structure having a period of 50 nm height is formed and the case where there is no periodic uneven structure. In the experiment, laser light (wavelength: 850 nm, power: lm W) was vertically incident from the back side of the substrate 8 to observe the photocurrent. It can be understood from FIG. 14 that when the periodic uneven structure 9 causing the plasmon resonance is formed, a photocurrent larger by two digits or more is obtained. The quantum efficiency at this time was about 40%.
- FIGS. 4 and 15 are a cross-sectional view and a plan view of an MSM type photodiode showing a fourth embodiment of the present invention.
- the MSM type photodiode has a structure of metal semiconductor metal (MSM) junction on a part of the semiconductor absorption layer 1 whose surface is insulated such as SOI (Silicon-on-Insulator). Then, the distance between the metal electrodes is set to be smaller than ⁇ / ⁇ ( ⁇ : wavelength of incident light, n: refractive index of semiconductor layer). Thus, light incident from the back surface side of the semiconductor absorption layer 1 is confined in the semiconductor absorption layer 1.
- 4 is a buried oxide layer provided on the support substrate 8
- 5 is a load resistance
- 6 is a bias power supply.
- An oxide film 7 is provided on the buried oxide layer 4
- a conductive film 2 is provided on the oxide film 7.
- 14 is Do not generate plasmon resonance! /, Forbidden band grating.
- the forbidden band grating 14 is provided outside the periodic uneven structure 9.
- 21 is an electrode pad.
- the MSM electrode 13 is made of a metal such as Al, Ag, Au, or Cu (or an alloy containing at least one of the metals as an essential constituent element) to induce surface plasmons. .
- a metal such as Al, Ag, Au, or Cu (or an alloy containing at least one of the metals as an essential constituent element) to induce surface plasmons.
- an undercoat film made of a metal such as Cr, Ta or Ni may be provided.
- Ti or the like as the underlying film as the opposing electrode film, it is possible to form an ohmic junction.
- a conductive film 2 capable of generating surface plasmons is provided adjacent to the periphery of the MSM junction. And, in order to cause surface plasmon resonance, a periodic uneven structure 9 is formed.
- FIG. 16 is a graph showing the characteristics of the MSM photodiode. That is, in a photodiode formed by arranging an Ag electrode of 120 nm in thickness on the surface of a Si semiconductor with a diameter of 200 nm, periodic structure causing plasmon resonance (for example, calculation of electromagnetic field by finite difference time domain method) The sensitivity characteristics are compared in the case of forming the 560 nm period, 50 nm height uneven structure) and the case where there is no periodic uneven structure.
- laser light (wavelength: 850 nm, power: lmW) was vertically incident from the back side of the substrate 8 to observe the photocurrent. It can be seen from FIG. 16 that when the periodic uneven structure 9 causing the plasmon resonance is formed, a photocurrent larger by two digits or more is obtained. The quantum efficiency at this time was about 50%.
- FIGS. 17, 18, 19, and 20 show surface plasmons of Example 1 (FIG. 1), Example 2 (FIG. 2), Example 3 (FIG. 3), and Example 4 (FIG. 4).
- a Schottky type in which a forbidden band grating 14 having a reflection function of surface plasmons, a protrusion shape 15, a groove shape 16, a periodic slit array or a minute aperture array 17 is formed outside the periodic uneven structure 9 causing resonance.
- FIG. 2 shows a cross-sectional view of a photodiode.
- any of the structures a quantum efficiency of about 2 to 3 times is obtained as compared with the case of the periodic uneven structure 9 alone. Then, the surface plasmons are efficiently reflected to condense the light to the Schottky junction and to localize the light energy to the semiconductor absorption layer.
- FIG. 21 is a schematic view showing an optical receiving module for 40 Gbps (gigabit per second) transmission equipped with the Schottky photodiode 22 according to the present invention.
- the photodiode is a Schottky type photodiode in which a substrate obtained by epitaxially growing a Ge film on an SOI substrate is used, and a Ni / Au electrode is provided thereon.
- a conductive film having a concavo-convex structure (a concavo-convex structure made of Ag (or Au) that enables light coupling and focusing by surface plasmon resonance) is provided around the photodiode.
- the concavo-convex cycle of the concavo-convex structure of the conductive film (metal film) is about 1.2 111, and in the case of using eight concavo-convex irregularities
- the outer diameter is about 20 m.
- the depth of the unevenness at this time was about 0.;! ⁇ 0.4 m.
- the diameter of the Schottky junction was about 0.3 to 0 ⁇ 7 m.
- the photodiode is mounted on a chip carrier 26. Then, an optical coupling force is made by the optical fiber 120 and the lens, and an electrical connection is made to the preamplifier IC 25 in the subsequent stage.
- a side-incidence waveguide type photodiode is often used for the mounted photodiode. This is the surface where light is incident on the semiconductor surface This is because in the incident type photodiode, high quantum efficiency can not be obtained if the absorption layer is thinned to reduce charge carrier transit time.
- the waveguide photodiode can achieve high quantum efficiency while keeping the charge carrier transit time short.
- the semiconductor absorption layer thickness is usually 1 m or less. In this case, the coupling tolerance with respect to the position of the optical fiber needs to be about ⁇ 1 ⁇ m, which is a major problem in both the mounting design and the manufacturing cost.
- the photodiode according to the present invention has an effective effective diameter of 20 am. For this reason, it is possible to set the bonding tolerance to ⁇ 2 m or more. As a result, optical coupling can be performed only by simple lens coupling. This makes it possible to reduce the cost of the optical transmission receiver module.
- Figure 22 shows the optical interconnect configuration between LSI chips on which the photodiode of the present invention is mounted.
- the light signal from the light signal input fiber 33 is irradiated by the concave mirror 36 to the photodiode 22 according to the present invention.
- the semiconductor material of the photodiode is Si
- the asperity period of the metal periodic structure at this time is 600 to 700 nm.
- a photodiode made of Si generates a photocurrent by further optically coupling near-field light generated by the metal periodic structure with the semiconductor absorption layer.
- a current corresponding to the optical signal is supplied to the LSI through the photodiode wiring layer 29.
- coupling tolerance regarding the position of the concave mirror and the photodiode can be taken to be ⁇ 1 ⁇ m or more.
- the photodiode wiring layer 32 is electrically connected to the photodiode wiring via 29 of the LSI.
- a planar optical waveguide or the like is Other methods can be used.
- a condensing mechanism such as a convex lens can be used.
- An electrical signal from the LSI is converted into an optical signal by a VCSEL (surface emitting laser) light source 27 having an electrical modulation mechanism from the light source and modulation electrical signal via 28 through the light source and modulation electrical wiring layer 31. Be done.
- the light signal is reflected by the concave mirror 36 and sent to the light signal output fiber 33.
- the VCSEL light source 27 equipped with an electrical modulation mechanism is replaced by another mechanism known to modulate light by electricity, such as a Mach-Zehnder modulator that modulates light from an external light source by electro-optical effect or thermo-optical effect. Can do.
- the mounted photodiode is a compound such as InGaAs grown on an InP substrate in order to speed up the response.
- a semiconductor material or the like is used.
- compound semiconductors have high costs that are not compatible with the manufacturing process of Si semiconductor devices.
- the photodiode of the present invention can use Si, the manufacturing cost can be reduced. Then, in the optical interconnect according to the present invention shown in FIG. 22, a high-speed photoelectric conversion operation of about 40 GHz was confirmed.
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Abstract
Description
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Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
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EP07832626A EP2110864A4 (en) | 2006-12-20 | 2007-11-28 | PHOTODIODE, OPTICAL COMMUNICATION DEVICE, AND OPTICAL INTERCONNECTION MODULE |
CN2007800471169A CN101563790B (zh) | 2006-12-20 | 2007-11-28 | 光电二极管、光通信装置及光互连模块 |
JP2008550080A JP5282887B2 (ja) | 2006-12-20 | 2007-11-28 | フォトダイオード、光通信デバイスおよび光インタコネクションモジュール |
US12/519,701 US20100200941A1 (en) | 2006-12-20 | 2007-11-28 | Photodiode, optical communication device, and optical interconnection module |
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US (1) | US20100200941A1 (ja) |
EP (1) | EP2110864A4 (ja) |
JP (1) | JP5282887B2 (ja) |
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JP2015019088A (ja) * | 2009-05-26 | 2015-01-29 | ユニバーシティ オブ ソウル インダストリー コーポレーション ファウンデーション | 光検出器 |
US9397249B2 (en) | 2009-07-06 | 2016-07-19 | University Of Seoul Industry Cooperation Foundation | Photodetector capable of detecting long wavelength radiation |
JP2014146703A (ja) * | 2013-01-29 | 2014-08-14 | Ren Solation Co Ltd | 光電変換素子 |
JP2016219668A (ja) * | 2015-05-22 | 2016-12-22 | 日本電信電話株式会社 | フォトダイオード装置およびフォトミキサモジュール |
JP2019128157A (ja) * | 2018-01-19 | 2019-08-01 | 国立大学法人電気通信大学 | 分光用デバイス、分光器、及び分光測定方法 |
JP7084020B2 (ja) | 2018-01-19 | 2022-06-14 | 国立大学法人電気通信大学 | 分光用デバイス、分光器、及び分光測定方法 |
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Also Published As
Publication number | Publication date |
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JP5282887B2 (ja) | 2013-09-04 |
EP2110864A1 (en) | 2009-10-21 |
CN101563790B (zh) | 2011-10-05 |
EP2110864A4 (en) | 2011-09-07 |
CN101563790A (zh) | 2009-10-21 |
US20100200941A1 (en) | 2010-08-12 |
JPWO2008075542A1 (ja) | 2010-04-08 |
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