WO2020209791A1 - Structure métal-isolant-semi-conducteur - Google Patents

Structure métal-isolant-semi-conducteur Download PDF

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Publication number
WO2020209791A1
WO2020209791A1 PCT/SG2020/050195 SG2020050195W WO2020209791A1 WO 2020209791 A1 WO2020209791 A1 WO 2020209791A1 SG 2020050195 W SG2020050195 W SG 2020050195W WO 2020209791 A1 WO2020209791 A1 WO 2020209791A1
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mis
layer
tunneling
antenna
metal
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PCT/SG2020/050195
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English (en)
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Yongxin Guo
Baohu HUANG
Siping GAO
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National University Of Singapore
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/0004—Devices characterised by their operation
    • H01L33/0037—Devices characterised by their operation having a MIS barrier layer
    • 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
    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/02—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
    • H01L33/04—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a quantum effect structure or superlattice, e.g. tunnel junction
    • H01L33/06—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a quantum effect structure or superlattice, e.g. tunnel junction within the light emitting region, e.g. quantum confinement structure or tunnel barrier

Definitions

  • the present invention relates broadly to a metal-insulator- semiconductor, MIS, structure, particularly to a CMOS compatible electrically driven plasmonic light source and detector for on-chip or chip-to-chip ultrafast data transfer, to a method of fabricating the MIS structure, to a method of generating light using the MIS structure, and to method of detecting light using the MIS structure.
  • the current intra- and inter-chip data transfer is often limited by the insufficient bandwidth and large footprint of the state-of-the-art global and intermediate interconnects, which are incapable of accommodating the upcoming on-chip architecture beyond the Moore’s Law.
  • the electrical driven quantum tunneling has become more and more promising in realizing high-speed and low-profile plasmonic light source owing to its unique capability of ultrafast response and breaking the diffraction limit.
  • Quantum mechanical tunneling allows electrons transport from one electrode through a layer of nanoscale oxide barrier to another electrode.
  • the tunneling current broadband fluctuates in the quantum tunneling junction accompanied by luminescence process. Different from the spontaneous emission in LEDs which require the recombination of electron-hole pairs, the generation of the plasmon in the tunneling junction does not require the participation of other processes.
  • the speed of quantum electron is of the order of femtosecond time scale [1], and more, the participation of plasmons in the quantum mechanical tunneling can make the device operated in nanoscale, which makes it possible as a high-speed on-chip electric driven quantum light source.
  • the local hot spots introduced by nanophotonic resonance can be used to enhance the conversion efficiency of electron to photon [8]
  • Fermi the inelastic electron tunneling proportion in tunneling junction can be adjusted by local density of optical states (LDOS) [6-7,9].
  • LDOS local density of optical states
  • Nano-plasmonic structures have been greatly developed because of their ability to dynamic collection and amplification of electromagnetic field in nanometer scale, and the radiation efficiency can be enhanced by designing high quality optical antenna [10].
  • efficient light generation from inelastic tunneling using self-assembled edge-to-edge silver nanocubes has been demonstrated by Qian et al. with the electro-optical conversion efficiency increased by three orders of magnitude, up to 2% [7].
  • the main challenge to the wide adoption of the quantum tunneling light source is its low external quantum efficiency.
  • Embodiments of the present invention seek to address at least one of the above problems.
  • a metal-insulator- semiconductor, MIS, structure comprising:
  • the metal antenna layer confines plasmons excitable in the tunneling junction
  • the doped semiconductor waveguide layer couples photons excited by the plasmons for propagation in the doped semiconductor waveguide.
  • a method of fabricating a metal-insulator- semiconductor, MIS, structure as defined in the first aspect is provided.
  • a method of generating light using a metal-insulator- semiconductor, MIS, structure as defined in the first aspect is provided.
  • a method of detecting light using a metal-insulator-semiconductor, MIS, structure as defined in the first aspect BRIEF DESCRIPTION OF THE DRAWINGS
  • FIG. 1 shows a diagram illustrating an embodiment of a device and operational procedure in accordance with the disclosed embodiments.
  • FIG. 2A shows a schematic x-y cross-section view of the device in accordance with the disclosed embodiments.
  • FIG. 2B shows a schematic top view of the device in accordance with the disclosed embodiments.
  • FIG. 2C shows a schematic y-z cross-section view of the device in accordance with the disclosed embodiments.
  • FIG. 2D shows a schematic y-z cross-section view of the partial magnification of the active region of the device shown in FIG. 2C.
  • FIG. 3A shows an energy band diagram for the device shown in FIG. 2 with applied bias voltage.
  • FIG. 3B shows a flowchart of an embodiment of a method in accordance with the disclosed embodiments.
  • FIG. 4A shows the normalized local density of optical states (FDOS) of the tunneling junction as a function of wavelength according to the example embodiments of FIG. 2.
  • FIG. 4B shows the photon extraction efficiency h ec ⁇ of the silicon waveguide in the tunneling junction as a function of wavelength according to the example embodiments of FIG. 2.
  • FIG. 4C shows the normalized output photon power P e t / Po from the silicon waveguide in the tunneling junction as a function of wavelength according to the example embodiments of FIG. 2.
  • FIG. 5 shows a schematic diagram of the electrically driven light emitting tunnel junction and an energy band diagram for tunneling across a MIS tunnel junction with a bias voltage Vei a An the inset, according to an example embodiment.
  • FIG. 6A shows, from top to bottom, three-dimensional (3D) schematic structures of P-MIS junction, an A-MIS junction, and a W-A-MIS junctions according to an example embodiment.
  • FIG. 6B shows a comparison of the normalized FDOS for the junctions of FIG. 6A.
  • FIG. 6C shows a comparison of radiation efficiency for the junctions of FIG. 6A.
  • FIG. 6D shows a comparison of normalized radiation power for the junctions of FIG. 6A.
  • FIG. 6E shows a comparison of intensity profiles of the y component of the electric field of surface plasmon polaritons and localized surface plasmon modes in the y-z plane for the junctions of FIG. 6A.
  • FIG. 7A shows a schematic of the numerical model for calculating the light emission from dipole emitter placed in the gap of the tunnel junction, according to an example embodiment.
  • FIG. 7B shows normalized LDOS p P /po according to the model of FIG. 7 A.
  • FIG. 7C shows extraction efficiency h ec ⁇ according to the model of FIG. 7A.
  • FIG. 7D shows normalized extraction power P ex Po at the resonant frequency of 1.35 pm as a function of position according to the model of FIG. 7A.
  • FIG. 7E shows intensity profiles of the y component of the electric field in the x-z plane of the interface between metal and barrier and the y-z plane of the middle of the nano-antenna at the resonant frequency of 1.35 pm, according to the model of FIG. 7A.
  • FIG. 8A shows a schematic of the numerical model for calculating the light emission from dipole emitter placed in the barrier of the bump-based tunnel junction, according to an example embodiment.
  • FIG. 8B shows a comparison of normalized LDOS p p / po with bump height h varies from 3 nm to 5 nm as a function of wavelength, according to the model of Fig. 8A.
  • FIG. 8C shows a comparison of extraction efficiency h ec ⁇ with bump height h varies from 3 nm to 5 nm as a function of wavelength, according to the model of Fig. 8A.
  • FIG. 8D shows a comparison of normalized extraction power P ext / Po with bump height h varies from 3 nm to 5 nm as a function of wavelength, according to the model of Fig. 8A.
  • FIG. 9A shows a schematic of the numerical model for calculating the light emission from dipole emitter placed in the barrier of the bump-based tunnel junction, according to an example embodiment.
  • FIG. 9B shows a comparison of normalized LDOS p P lpo with the length l of the nano-antenna varies from 300 nm to 340 nm as a function of wavelength, according to the model of FIG. 9A.
  • FIG. 9C shows a comparison of extraction efficiency h ec ⁇ with the length l of the nano- antenna varies from 300 nm to 340 nm as a function of wavelength, according to the model of FIG. 9A.
  • FIG. 9D shows a comparison of normalized extraction power P ex Po with the length l of the nano-antenna varies from 300 nm to 340 nm as a function of wavelength, according to the model of FIG. 9A.
  • FIG. 10A shows a three-dimensional (3D) schematic diagram of Au nano-antenna coupled MIS tunneling light source with a silicon waveguide, according to an example embodiment.
  • FIG. 10B shows the partial enlargement of the schematic diagram of the electrically driven tunnel junction of FIG. 10A and energy band diagram for tunneling across a MIS junction with a bias voltage V7 3 ⁇ 4hab in the inset.
  • FIG. 11A shows normalized LDOS p p /po, extraction efficiency h ec ⁇ at the resonant waveguide of 1.3 pm as a function of dipole positions, according to example embodiments.
  • FIG. 11B shows normalized extraction power P ex Po at the resonant waveguide of 1.3 pm as a function of dipole positions, according to example embodiments.
  • the schematic of the numerical model for calculating the light emission from dipole emitter placed in the 2-nm- thick barrier layer of the tunnel junction is shown in the inset.
  • FIG. 12A shows schematic diagrams of three configurations of excitation positions of the y component of the electric field in the x-z plane of the interface between metal and barrier and the y-z plane of the middle of the nano-antenna at the resonant frequency of 1.35 pm, according to example embodiments.
  • FIG. 12B shows intensity profiles of the y component of the electric field in the x-z plane of the interface between metal and barrier and the y-z plane of the middle of the nano-antenna at the resonant frequency of 1.35 pm, according to example embodiments.
  • FIG. 13 A shows a comparison of the normalized LDOS between two output modes in the light source according to an example embodiment.
  • FIG. 13B shows extraction efficiency between two output modes in the light source according to an example embodiment.
  • FIG. 13C shows normalized extraction power between two output modes in the light source according to an example embodiment.
  • FIG. 14A shows a comparison of normalized LDOS p P /po with the length of the nano-antenna varies from 140 nm to 300 nm as a function of wavelength, according to example embodiments.
  • FIG. 14B shows extraction efficiency h ec ⁇ with the length of the nano-antenna varies from 140 nm to 300 nm as a function of wavelength, according to example embodiments.
  • FIG. 15A shows normalized LDOS, photon extraction efficiency and the normalized extraction power near the resonant frequency of 1.3 pm, as a function of electrode location, for a 30 nanometer wide electrode placed at one end of the antenna and moved to the other end at a step length of 14.5 nm, according to example embodiments.
  • FIG. 15B shows normalized LDOS, photon extraction efficiency and normalized extraction power vs the variation of electrode width at the resonant frequency of 1.3 pm, when the middle position of the antenna is selected for electrode connection, and the width of the electrode varies from 10 to 175nm, according to example embodiments.
  • FIG. 17 shows normalized LDOS p p /po, extraction efficiency h ec ⁇ and normalized extraction power P ext /Po vs different doping concentrations of the n-type silicon as a function of wavelength, according to example embodiments.
  • Embodiments of the present invention aim to address the fundamental limitations of inelastic electron tunnel junction for the on-chip light source and optical interconnects, whose performance is strongly sensitive to the conversion efficiency of electron-to-plasmon and plasmon-to-photon.
  • the proposed designs according to example embodiments are able to use strong localized plasmon confinement of an optical nanoantenna in the MIS tunnel junction to provide a large local density of optical states (LDOS) and are able to bridge the size mismatch between nanoscale volumes and far-field radiation to preferably achieve improved performance.
  • LDOS optical states
  • CMOS -compatible electrical driven light source with its efficiency enhanced by nano-antenna is provided.
  • Three orders of magnitude of far-field light emission enhancement is achieved in the silicon waveguide in comparison with traditional planar MIS tunnel junctions.
  • the strong localized plasmon confinement in the optical nanoantenna provides a large local density of optical states (LDOS), which greatly enhances the electron-to-plasmon conversion efficiency; 2) the optical antenna efficiently bridges the size mismatch between nanoscale volumes and far-field radiation thus strongly enhances the plasmon to photon conversion efficiency; 3) the silicon waveguide provides better photon confinement and much lower loss compared with the commonly used surface plasmon polariton (SPP) waveguides in MIM junction-based plasmonic interconnects.
  • SPP surface plasmon polariton
  • example embodiments of the present invention provide a nanoantenna enhanced electrical driven silicon light source based on inelastic electron tunnel junction for the high speed miniaturization and CMOS compatible on-chip optical interconnects.
  • the electric driven tunnel junction enables the transport of electrons across a nanoscale barrier between the Au nano-bump and doped silicon waveguide according to an example embodiment.
  • the strong localized plasmon mode is excited by the broadband fluctuations in the tunneling current where the electromagnetic field will be constrained in the area of nanoscale, and that constraint will greatly enhance the local density of optical states (LDOS) and then enhance the spontaneous emission rate.
  • the optical antenna in an example embodiment will also solve the wave vector mismatch between plasmon and photon, enhancing the far- field radiation efficiency of light source in free- space.
  • Embodiments of the present invention are desirable as a novel solution for the next generation integrated opto -electronic circuits for high-speed on-chip information processing and chip-to-chip communications.
  • the example embodiments described herein involve an electrically driven silicon light source with a photon emission spectrum whose peak value can be tuned by modifying the size of the nano-antenna.
  • the tunneling current broadband fluctuates in the quantum tunneling junction accompanied with a wide spectrum of luminescence process from visible to near infrared. That provides a broadband spontaneous emission for many applications, while the optical nanoantenna can manipulate the spontaneous emission spectrum at selected peaks and greatly enhance the far-field radiation intensity.
  • devices may be configured to operate within portions of the spectrum, such as from the 1.31 pm to 1.55 infrared spectral range.
  • the embodiments of the devices described herein introduce plasmonic nanostructure to dynamic collection and amplification of electromagnetic field in ultrasmall volumes.
  • the total spontaneous emission is proportional to the electron-to-plasmon conversion efficiency and the antenna radiation efficiency.
  • the former is described by Fermi’s golden rule which is related to the applied bias voltage and the local density of optical states (LDOS). That means the proportion of inelastic electron tunneling in the total tunneling current in the tunneling gap can be adjusted by the LDOS.
  • Example embodiments of the present invention benefit from the use of the optical nanoantenna in the MIS tunneling junction - the coupling between the electrons and plasmons is greatly enhanced by the localized plasmon resonance which is excited by the inelastic tunneling electrons.
  • the described example embodiments exploit nanoantenna as an enhanced far-field photon radiative element whose plasmon-to-photon conversion efficiency can be improved by the solution of wave vector mismatch.
  • the main challenge for light generation from inelastic electron tunneling is its wave vector mismatch between nanoscale volumes and far-field radiation.
  • SPP surface plasmon polarizations
  • example embodiments operate based upon a concept that differs from the typical light-emitting diodes, in which p-n junction diodes serve as the active area of the device for light emission.
  • the disclosed embodiments do not feature a p-n junction diode, but rather the light emission of inelastic electron tunneling, that provide the potential to enable CMOS -compatible, high-speed silicon waveguide coupled light sources.
  • example embodiments of the present invention can also work as a photoelectric detector because of the reversibility of quantum processes.
  • the optical TM mode are bound and transmitted in silicon waveguide, and the photon emission wavelength can be tuned to different spectrum bands in the near-infrared regions of the electro -magnetic spectrum by changing the sizes of the nanoantenna.
  • a metal electrode is connected in the middle of the gold nanoantenna where the dipole resonance mode is excited to reduce the impact on the localized plasmon resonance of the optical antenna.
  • Devices such as those described according to example embodiments herein can serve as a low-optical power light source in combination with a photodetector for applications such as optical signal routing, optical interconnect, and on-chip information transfer.
  • FIG. 1 shows a diagram illustrating an embodiment of the active region of a device 100 and operational procedure in accordance with an example embodiment.
  • the active region of the device 100 includes a handle layer 110, a BOX layer 120, a doped semiconductor layer 130, a tunnel barrier 140 disposed on the active regions of the doped dielectric 130 as part of a thick field oxide 150 that was disposed on the BOX layer 120, doped semiconductor layer 130 to electrically isolate the various devices from each other.
  • a metal nanoantenna 160 connected to a metal electrode 170 is disposed over the tunnel barrier 140.
  • An applied voltage source V is connected to electrode 170 and the doped semiconductor 130.
  • Doped semiconductor 130 comprises a high-k dielectric material that is capable of providing quantum tunneling electrons or holes and is almost transparent in the near infrared.
  • High-k material means a dielectric constant k greater than that of S1O2 that can provide good photonic confinement so that light can travel directionally along the dielectric waveguide.
  • the semiconductor 130 comprises degenerately doped n- type silicon.
  • semiconductor 130 may comprise p-doped silicon.
  • the tunnel barrier 140 of the MIS junctions may comprise S1O2 for example.
  • tunnel barrier 140 may be disposed on an active region(s) of the semiconductor 130 via a device isolation technique including, but not limited to, the thermal oxidation of silicon or physical deposition technique.
  • gold was chosen as the material of the metal antenna 160 and the top electrode 170, by way of example, not limitation.
  • Devices according to an example embodiment may be made using variations of materials for the underlying semiconductor, tunneling barrier and the metal antenna. Selecting the proper tunneling dielectric materials and their thicknesses can optimize the amount of bias voltage needed to emit.
  • one embodiment of a device structure is configured to emit near infrared light near the 1310 nm telecommunications band. It should be noted that optical intensity could be increased by several orders of magnitude with future optimization of the device structure in various embodiments, such as increasing the tunneling current density through an optimized tunneling barrier (e.g. but not limited to MgO, GdiC , hexagonal boron nitride, bilayer tunnel barriers, etc.).
  • an optimized tunneling barrier e.g. but not limited to MgO, GdiC , hexagonal boron nitride, bilayer tunnel barriers, etc.
  • FIGS. 2 A to 2 D show schematic drawings illustrating device 200 according to an example embodiment.
  • FIG. 2A shows a schematic x-y cross-section view of the device 200
  • FIG. 2B shows a schematic top view of the device 200
  • FIG. 2C shows a schematic y-z cross-section view of the device 200
  • FIG. 2D shows a schematic exploded y-z cross- section view of the partial magnification of the active region of the device 200 shown in FIG. 2C.
  • the device 200 provides a tunneling light source with a nanoantenna based metal (Au/Cr) 208 - isolator (including silica but not limited to silica) 206 - n-doping silicon 204 structure.
  • the MIS junction in the device 200 comprises a 20 nm thick, 40 nm width and 150 nm long Au nanoantenna (1 nm thick Cr is used as the adhesion layer) 208 with a bump 207 in one end of it. Under the bump 207, a 2 nm thick silicon oxide S1O2 layer is used as the tunneling barrier 206. Disposed between the bottom of the other end of the Au antenna 208 (i.e.
  • the silicon waveguide 204 is 5 nm thick silicon oxide 203.
  • the doped dielectric waveguide 204 is a 300 nm thick and 300 nm width silicon waveguide on the BOX layer 202 of the silicon-on-insulator (SOI) wafer 211.
  • the silicon waveguide 204 is connected by a 50 nm thick n-doped silicon electrode 205, and flattened by the thick filed oxide 203.
  • the thick field oxide 203 (e.g. S1O2) used for device isolation is disposed across the SOI wafer 211 prior to the deposition of the tunneling barrier 206.
  • a metal electrode 209 is connected in the middle of the gold/Cr nanoantenna 208, and a second electrical contact 210 is disposed over a portion of the doped silicon electrode 205.
  • the device 200 provides an electric-driven MIS light source (including the form of Au/Si02/n-Si quantum tunnel junction 201 coupled with a silicon- based optical waveguide 204) for TM mode.
  • the indices of the n-doped silicon 204 Doped silicon with a resistivity of 1 ⁇ 20 ohm.cm is used here.
  • the silicon oxide 203 index at the wavelength of 1310 nm are about 3.45 and 1.45, respectively, in this example embodiment.
  • FIG. 3A shows a simplified energy level diagram 300 of a Au/Si0 2 /n-Si quantum tunnel junction according to the device 200 (FIGS.2 A to 2 D) according to an example embodiment of the present invention with bias Vei as , illustrating the principle of operation for a device using inelastic tunneling electron luminescence.
  • the arrows indicate the tunneling process including inelastic and elastic electron tunneling 302, 304, respectively.
  • FIG. 3B shows a flowchart of an example embodiment of a method 310 in accordance with the present invention. Some or all of the steps of method 310 may be performed by a device such as device 100 shown in FIG. 1 or device 200 shown in FIGS. 2A-2D. As such, reference may be made to any of the devices/methods shown in such figures when discussing the example embodiment of the method 310 shown in FIG. 3B.
  • the bias voltage is applied to an MIS tunnel junction.
  • quantum mechanical electrons tunneling through barrier oxide in elastic and inelastic ways, respectively.
  • plasmons are electrically generated, while the inelastic electron tunneling proportion is regulated by nanostructure.
  • photons are generated by nanostructures through plasmons-to- photons transformation and coupled into a waveguide stmcture(s).
  • the opposite process of an embodiment of a method 310 in accordance with another example embodiment can be applied to detectors.
  • the detection method may comprise detecting the generated plasmons via a modified tunnel-current under bias induced tunneling.
  • the total light emission in embodiments of the present invention is proportional to the electron-plasmon conversion efficiency and the optical antenna radiation efficiency.
  • the former is described by Fermi’s golden rule which is related to the applied bias voltage and the local density of optical states (LDOS).
  • the LDOS p can be obtained from
  • po co 2 p 2 c 3 is the vacuum density of states
  • P tot is the total dissipated power
  • Po is the radiated power of a dipole of equal moment in a vacuum environment.
  • FIG. 4A shows the normalized local density of optical states (LDOS) of the tunneling junction as a function of wavelength according to the example embodiment of FIGS. 2 A to 2D.
  • the normalized local density of optical states p/po (curve 400) clearly demonstrates a spontaneous decay enhancement in the frequency of 1300 nm according to the example embodiment.
  • a strong spontaneous emission enhancement occurs in the nanoscale local plasmon resonance confinement region in the example embodiment, which is three times stronger than that in the region where there is no resonance.
  • the spontaneous emission power is mainly attenuated by ohmic loss and photon radiation.
  • most of the photonic radiation energy P md coming from the Au nanoantenna are collected by the silicon waveguide. If P ext is defined as the energy extracted by the waveguide, then the extraction efficiency can be expressed as
  • FIG. 4B shows the photon extraction efficiency h ec ⁇ (curve 410) of the silicon waveguide in the tunneling junction as a function of wavelength according to the example embodiment of FIGS. 2A to 2D.
  • a peak extraction efficiency occurs in the frequency of 1300 nm according to the example embodiment. It’s worth noting that, when the extraction efficiency is the highest, the operating frequency of the light source in the example embodiment of FIGS. 2 A to 2D is the same with that of the maximum spontaneous emission of the light source. It means that the most efficient radiated power will be extracted benefiting from the same operating frequency.
  • FIG. 4C shows the normalized output photon power P e t / Po (curve 420) from the silicon waveguide in the tunneling junction as a function of wavelength according to the example embodiment of FIGS. 2 A to 2D.
  • the normalized output photon power is increased by three orders of magnitude up to 7200 compared to the spontaneous emission energy of an electric dipole in free space when operated in the resonance frequency.
  • the MIS junction 500 is formed by an Au nano-bump 502, a thin layer of insulator 504 and an n-doped silicon waveguide 506.
  • the electrons in the n-doped silicon 506 tunnel through the barrier layer 504 to the nano-bump 502 of the nano-antenna 508 accompanied by light emission.
  • the broadband fluctuations in the tunneling current induce the collective oscillations of free electrons on the metal surface, which is localized by the nano-antenna 508.
  • FIG. 5 A simplified energy band diagram of the quantum tunnel junction with bias V BMS is again shown in the inset of FIG. 5, which illustrates the principle of operation for a device with inelastic tunneling electron luminescence according to an example embodiment.
  • the arrows 510, 512 indicate tunneling process including inelastic and elastic electron tunneling, respectively.
  • the majority of electrons tunnel elastically, without losing energy.
  • the other electrons inelastically tunnel through the atomic scale barrier 504 and lose their energy under the condition hco ⁇ eVei as , where h is the reduced Planck constant, co is the angular frequency of the optical mode and V BMS is a bias voltage.
  • the lost energy of electron excites plasmon(s) and then decays in various relaxation ways including the radiative or non-radiative mechanisms.
  • a broadband vertical dipole (quantum emitter) is placed in the middle of an atomic scale barrier to mimic the fluctuating electron tunneling process in the quantum tunnel junction [6].
  • the total photon radiation power is proportional to the electron-to-plasmon conversion efficiency / .. p and radiation efficiency r jumnwu ⁇
  • the former is described by Fermi’s golden rule which is related to the applied bias voltage and the LDOS [7].
  • the LDOS p p can be obtained from equation (1) above.
  • the radiation efficiencyj antenna is typically deduced by calculating the ratio between the radiated power P m ,i and the total power P tot , that can be expressed as: f ⁇ antenna P rad ⁇ P tot (3).
  • the nano-antenna 508 coupled with silicon waveguide 504 in the tunneling light source plays an important role in the near-field plasmon confinement and far-field photon radiation enhancement.
  • three kinds of MIS tunnel junctions are investigated: (i) typical planar MIS junction (P-MIS) 600; (ii) nano antenna enhanced MIS junction (A-MIS) 602; and (iii) nano-antenna enhanced MIS junction coupled with waveguide (W-A-MIS) 604 as shown in FIG. 6A.
  • the P-MIS and A-MIS junctions 600, 602 are composed of 20 nm thick Au, 2 nm thick S1O2, and a semi-infinite n- doped silicon substrate.
  • An infinitely large Au layer 606 is used for P-MIS 600, whereas a nano-antenna 608 of in-plane dimensions of 40x300 nm 2 for A-MIS 602.
  • a 300 nm thick n-doped silicon on insulator is used to replace the semi-infinite silicon substrate 610, and a 300 x 300 nm 2 silicon waveguide 612 is etched along the long axis (z-axis) of the nano-antenna 614.
  • Such a waveguide 612 is able to provide tight confinement and directional transmission of TM mode.
  • the resistance of 0.1-10 ohm.cm of doped silicon is used because it ensures light emission [11], and low propagation losses for MIS junctions. All material parameters are obtained from standard materials library in Lumerial FDTD software.
  • the normalized LDOS plpo , the photonic radiation efficiency h antenna and the normalized radiation power P md lPo as a function of wavelength are shown in FIGS. 6 A- 6 D for the P- MIS 600, the A-MIS 602, and the W-A-MIS 604, respectively.
  • the higher LDOS p I po is obtained in the latter two tunnel junctions (A-MIS 602, W-A-MIS 604) with the values of 11800 and 11000 at the resonant frequency around 1.35 pm, respectively.
  • the normalized LDOS of A-MIS 602 and W-A-MIS 604 is almost three times that of the P-MIS 600 junction as shown in FIG. 6 B.
  • FIG. 6 D The normalized LDOS of A-MIS 602 and W-A-MIS 604 is almost three times that of the P-MIS 600 junction as shown in FIG. 6 B.
  • FIG. 6 B As shown in FIG.
  • the far-field radiation efficiency of 30% and 32% in the A- MIS 602 and W-A-MIS 604 junctions are obtained, respectively, which is almost two orders of magnitude higher than the radiation efficiency of 0.38% in the P-MIS 600 junction.
  • the slight deviations between the normalized LDOS and radiation efficiency in A-MIS 602 and W-A-MIS 604 junctions are mainly caused by the change of substrate environment. Therefore, this explains why the spontaneous radiation rate in the P-MIS 600 junction is so inefficient and low.
  • the normalized radiation powers in P-MIS 600, A- MIS 602 and W-A-MIS 604 tunnel junctions are 15, 3570 and 3540 at the resonant frequency around 1.35 pm, respectively.
  • a significant enhancement of light emission occurs in the latter two junctions due to the nano-antenna.
  • intensity profiles of the y component of the electric field of surface plasmon polaritons (SPP) and localized surface plasmon (LSP) modes in the y-z plane of the three junctions are given as shown in FIG. 2 E. It can be seen that the nano-antenna enhanced tunnel junctions (A-MIS 602, W-A-MIS 604) have better radiation capability.
  • the commonly used P-MIS 600 junction is able to produce comparable LDOS as shown in FIG. 2 B
  • the low radiation efficiency caused by wave vector mismatch largely limits the spontaneous radiation rate.
  • the SPP modes excited by inelastic electron tunneling are mainly dissipated by the metal loss in P-MIS 600 and only a small amount of SPP energy can radiate and scatter by rough surface and edges of metal in real fabrication [12].
  • A-MIS 602 and W-A-MIS 604 junctions show higher LDOS and radiation efficiency, leading to two orders of magnitude enhancement of light emission over P-MIS 600 junction.
  • an additional waveguide extraction efficiency h ec ⁇ is defined as the ratio between the waveguide extraction power P ext and the total power P m , expressed as equation (2) above.
  • the tunneling excitation position affects the performance of the light source [13], and multipolar interference may also cause the elimination of the output optical field [14, 15, 16], the impact of dipole emitter location that is under the nano-antenna on the performance of light emission was also studied.
  • a 20-nm-thick, 40-nm-wide, 300-nm-long gold antenna and 2-nm-thick tunnel barrier are selected.
  • the dipole 700 is placed along z-axis direction from -150 nm to 150 nm in the insulator layer 702.
  • the normalized LDOS p / po , extraction efficiency h ec ⁇ and normalized extraction power P ext / Po at the resonant frequency of 1.35 pm as a function of positions are given as shown in FIG. 7 B to D.
  • Three peaks in the middle and two ends of the optical antenna can be seen.
  • the strong position dependence phenomenon is due to the excitation of the quadrupolar plasmon mode in the optical antenna [17] which produces a strong field confinement in the nanoscale volumes.
  • the intensity profiles of the y component of the electric field of the nano-antenna in the x-z and y-z planes at resonant frequency are shown in FIG. 7 E, which confirms the localized plasmon resonance.
  • the tunneling excitation position should be close to the middle position of the nano-antenna, according to preferred embodiments of the present invention.
  • the plasmon mode in the tunnel junction is excited by the electrons flowing through the middle of the nano-antenna 804.
  • the influence of the height of the Au bump 800 on the light emission was calculated to provide reference for various embodiments.
  • the thickness of the barrier 802 in tunnel junction is preferably about 1 ⁇ 3 nm for the effective coupling between the inelastic electron and plasmon [12].
  • the thickness of the barrier 802 in the tunnel junction is fixed to 2 nm in one example embodiment, and the length of the bump 800 is half the length of the nano-antenna 804.
  • the normalized LDOS p / po, extraction efficiency h ec ⁇ and normalized extraction power P e t / Po as a function of wavelength are given in FIGS. 8 B to 8D, respectively.
  • the maximum value of the normalized LDOS of each junction slightly decreases from 9056 to 8310 because of a weaker coupling between the dipole emitter and the plasmon mode, as shown in FIG. 8 B.
  • the resonant frequency blue shifts from 1.24 pm to 1.21 pm with the increase of h due to the change of the surrounding environment of the nano-antenna, as shown in FIG. 8 C.
  • the blue shift also occurs in the extraction efficiency, except that the maximum extraction efficiency remains unchanged at around 29%.
  • the resonant frequency of the normalized extraction power blue shifts with the increase of bump height, and the maximum extraction power decreases from 2675 to 2400.
  • a higher metal bump will slightly reduce the spontaneous emission of the light source, so the bump height should be reduced as far as possible without changing the condition that the barrier at the edge of the nano-antenna is thick enough to allow most of the current tunneling through the junction region of metal bump, according to a preferred embodiment.
  • 3-nm height of the bump 800 is chosen in an example embodiment.
  • the nano-antenna has size can be changed to get the desired resonant frequency from visible to infrared light. That would be beneficial for light source design.
  • the effect of the antenna length on the performance of the light source is investigated.
  • the nano-antenna length is defined as l
  • the length of the metal bump is 1/2.
  • Other parameters are fixed as shown in FIG. 9 A, where the width of the metal antenna 900 is 40 nm, the thickness is 20 nm, and the height of the bump 902 is 3 nm.
  • the normalized LDOS, the extraction efficiency and the normalized extraction power under different lengths of nano-antennas are shown in FIGS. 9 B to 9D, respectively.
  • the resonant frequencies in their normalized LDOS, extraction efficiency and normalized extraction power all red shift from 1.24 pm to 1.37 pm with the length l increasing from 300 nm to 340 nm.
  • the variation of the resonant frequencies of the normalized LDOS and extraction efficiency are synchronous, which is important to maximize the normalized extract power.
  • the peak normalized LDOS and extraction efficiency remained around 9000 and 30% respectively, which means the peak extraction strength doesn’t change with the variation of antenna length. Therefore, the color of the emitted light can be tuned by modifying the antenna size without significantly sacrificing the performance of the device according to example embodiments.
  • the length l of 320 nm for operating wavelength of 1.3 pm is chosen in an example embodiment.
  • the electrically driven MIS light source is formed by an Au antenna 1000 with 3-nm-thick nano-bump under the left half, a thin layer of insulator 1002 and an n-doped silicon waveguide 1004 on the SOI substrate 1008.
  • the electrons in the n-doped silicon 1004 tunnel through the barrier layer to the nano-bump (a‘point-like’ excitation structure) accompanied by light emission which is then collected by the silicon waveguide 1004.
  • the local schematic details are shown in FIG. 10 B.
  • the broadband fluctuations in the tunneling current induce the collective oscillations of free electrons on metal surface, which is localized by the nano antenna. Both the electron-to-plasmon and plasmon-to-photon conversion efficiencies benefit from the nanoscale field confinement.
  • FIG. 10 B A simplified energy band diagram of the quantum tunnel junction with bias V7 3 ⁇ 4 Struktur is again depicted in the inset of FIG. 10 B, which illustrates the operation principle for the device with light emission excited by tunneling electron. Electron tunneling through a barrier is divided into elastic tunneling without losing energy and inelastic tunneling with light emission under the condition hco ⁇ eVei as , where h is the reduced Planck constant, w is the angular frequency of the optical mode.
  • the light emission process can be divided into two steps:
  • a broadband vertical dipole (quantum emitter) is placed in the middle of atomic scale barrier to mimic the fluctuating electron tunneling process in quantum tunnel junction [1,6,7,18].
  • the quantum efficiency (number-of-radiation photons / number-of-tunneling electrons) of the proposed device is presented as:
  • h e-p being the electron-to-plasmon conversion efficiency and h antenna the antenna radiation efficiency as well as the plasmon-to-photon conversion efficiency.
  • the normalized LDOS can be obtained from equation (1) above, where P tot is the total electrically excited plasmon power, and Po is the radiated power of a dipole moment in a vacuum environment.
  • the photon radiation efficiency h aMehha is typically deduced by calculating the ratio between the photon radiated power P rad and the total dissipated power P tot , that can be expressed as equation (3) above.
  • an additional waveguide extraction efficiency h ec ⁇ is defined as the ratio between the waveguide extraction power P ext and the total power P tot , expressed as equation (2) above.
  • the nano-antenna coupled with silicon waveguide in the tunneling light source plays an important role in the near-field plasmon confinement and far-field photon radiation enhancement.
  • three kinds of MIS tunnel junctions were investigated and the results have been described above with reference to FIGS. 6 A to 6 E.
  • the influence of dipole emitter location that is under the nano-antenna on the performance of light emission was studied.
  • a 30-nm- thick, 40-nm-wide, 150-nm-long gold antenna 1100 and 2-nm-thick tunneling barrier 1102 are selected with the working wavelength at 1.3 pm.
  • the dipole 1104 is placed along z-axis direction from -75 nm to 75 nm in the middle of the barrier layer 1102.
  • the normalized LDOS p p /po, and extraction efficiency h ec ⁇ as a function of positions are given as shown in FIG.
  • the corresponding enhancements of spontaneous radiation extraction are shown in FIG. 12 B. It can be seen that the normalized extraction powers are the same when both ends are excited respectively, and the maximum P ex JPo reaches 8500 at the resonance frequency (see Left and Middle of FIG. 12 B). However, the normalized spontaneous emission enhancement is only nearly 35 around the resonant frequency of 1.3 pm (see the right graph in FIG. 12 B), instead of the superposition of the output power excited by the two respective dipole sources. The corresponding resonant modes in the nano-antenna are further observed, as shown in the insets in the graphs in FIG. 12B. The same dipole pattern is excited in the nano-antenna but with a phase difference of p, when separately excited at both ends by a single dipole source.
  • phase of dipole emitter is the same and do an analysis of multipolar interference under this assumption, which does not mean that the real situation is so or not. But it is reasonable to calculate the impact of the nonconstructive interference that may occur and to eliminate that possibility by using point-like excitation source by way of the nano-antenna according to preferred embodiments for it will greatly inhibit the performance of the light source when nonconstructive interference occurs.
  • the influence of the excitation sources at different positions under the nano antenna on the performance of the tunnel junction light source according to example embodiments was investigated, and the influence of the multipolar interference on the device performance was also analyzed.
  • the former determines the location of the protrusion, and the latter gives the existence of the protrusion according to a preferred embodiment.
  • the n-doped silicon plays both the role of providing inelastic tunneling electron for the light source and the role of photons capture and directional output in the device according an example embodiment.
  • the influence and the principle of use of two doping concentrations (low doping and heavy doping) are analyzed further below. In the following, the characteristics of the output polarization of the light source is analyzed next.
  • FIGS. 13 A to 13 C The comparison of the normalized LDOS, extraction efficiency and normalized extraction power between two output modes in the light source according to an example embodiment are shown in FIGS. 13 A to 13 C, respectively.
  • a nearly 25-fold increase in normalized LDOS and a 300-fold increase in extraction efficiency are achieved for TM mode compared to the TE mode being coupled.
  • the direction of the main electric field component of the TM mode near the antenna in the waveguide is the same as the electric field component of the plasmon mode in the bottom surface of the nano-antenna and the tunneling direction of the electrons in the barrier layer according to an example embodiment, which advantageously ensure a more efficient coupling between electrons, plasmons and photons.
  • a nearly 8000-fold enhancement of the normalized extraction power is obtained in TM mode output.
  • the light source according to an example embodiment has good polarization output characteristics.
  • the nano-antenna has size can be changed to get the desired working frequency. That would be beneficial for light source design.
  • the effect of the antenna length on the performance of the light source is given as shown in FIG. 14.
  • the width of the Au nano-antenna is 40 nm
  • the thickness is 30 nm
  • the height of the Au protrusion is 3 nm.
  • the nano-antenna length is changed from 140 to 300 nm with the step length of 20 nm, and the length of the metal bump is half of that of nano-antenna and located in the left of antenna as shown in FIG. 9 B.
  • FIGS. 14 A and 14 B The normalized FDOS and the extraction efficiency under different lengths of nano-antenna are shown in FIGS. 14 A and 14 B, respectively.
  • Two peak curves appear as shown in the dotted line areas and vary with the length of the antenna. Further observations show that these correspond to the dipole and quadrupole resonant modes of the nano-antenna, respectively. It is understandable that higher order modes would appear in the frequency band of interest as the nano-antenna gets longer. This is consistent with the resonance characteristics of the nanorod [21, 24, 25].
  • the resonant frequencies in their normalized FDOS, and extraction efficiency of both dipole and quadrupole modes all red shift as the antenna length increases.
  • the corresponding resonance waveguide changes from 1.24 pm to 1.6 pm, hence a wide operating wavelength can be obtained according to example embodiments.
  • the variation of resonant frequency in the normalized FDOS and photon extraction efficiency is consistent when the antenna length is changed, which is different from the device whose structure parameters need to be specially selected as described in reference [7]. This is important to maximize the normalized extraction power.
  • the peak normalized FDOS and extraction efficiency remained around 24000 and 30% respectively, which means the peak extraction strength doesn’t significantly change with the variation of antenna length. Therefore, the color of the emitting light can be tuned by modifying the antenna size without significantly sacrificing the performance of the device, according to example embodiments.
  • the nano-antenna acts as both a metal layer of the MIS junction and a part of the bias electrode.
  • An appropriate electrode design connecting with the nano-antenna is preferred to maintain the device performance, because the metal electrodes may cause interference to the plasmon resonance mode of the nano antenna.
  • a 30-nm-thick metal stripe is used as the electrode that can be deposited with the nano-antenna when processed. The influences of different electrode connection positions in the nano-antenna and electrode widths on device performance according to example embodiments are calculated as shown in FIGS. 15 A and 15 B, respectively.
  • a 30-nanometer wide electrode is placed at one end of the antenna and moved to the other end at a step length of 14.5 nm. Then the corresponding normalized LDOS, photon extraction efficiency and the normalized extraction power near the resonant frequency of 1.3 pm are given as shown in FIG. 15 A.
  • the maximum values of 24000, 27% and 8000 of the all three parameters are obtained in the middle of the antenna which is slightly close to the protrusion (-16nm), which is just a slight reduction in device performance compared to those of 25000, 30% and 9000 without electrode.
  • the reason why the electrode connection position deviates from the center position of the nano-antenna is that the Au bump according to an example embodiment investigated here slightly changes the symmetry of the dipole mode of the nano-antenna.
  • the influence on the device according to example embodiments can be effectively reduced by selecting the appropriate electrode connection position.
  • the effect of electrode width change on device performance according to example embodiments is analyzed. It is evident that the narrower the metal electrode, the smaller the effect on the resonant plasmon pattern of the nano-antenna, and the better the device performance. It was tried to analyze how wide the electrode is while the device performance is still within the acceptable range when the size and working frequency of the device are fixed. The middle position of the antenna is selected for electrode connection, and the width of the electrode varies from 10 to 175nm, which is the same as the length of the antenna when at its widest.
  • the corresponding normalized LDOS, photon extraction efficiency and normalized extraction power vs the variation of electrode width at the resonant frequency of 1.3 pm are given, as shown in FIG. 15 B. All three decrease almost monotonically with electrode width. Even if the electrode width is 60nm, the normalized LDOS, photon extraction efficiency and normalized extraction power of the device are respectively 24,000,19% and 4500, hence the device performance is somewhat reduced but still acceptable.
  • a nano-plasmonic enhanced electrically driven light source comprising n-doped silicon and Au protrusion/bump in the nano antenna with nanometer barrier gap between them has been analyzed.
  • the light emission excited by inelastically tunneling electron is collected by the silicon waveguide.
  • the strong electrically excited plasmon confinement in the nano-antenna provides a large LDOS and far- field radiation efficiency, which greatly enhances the electron-to-plasmon and plasmon-to- photon conversion efficiencies.
  • a silicon-photonic light source with radiation power 9000 times than spontaneous emission power in free space has been achieved at an operating frequency of 1.3 pm, according to an example embodiment.
  • the commercial software Lumerical FDTD Solutions was used to simulate the MIS light source according to example embodiments.
  • Broadband electric dipole is e.g. located in the middle of atomic scale barrier to mimic the fluctuating electron tunneling process in quantum tunnel junction [6].
  • All material parameters are obtained from standard materials library built in the software, where the optical properties of Si and S1O2 are taken from [26], and the dispersive permittivity of Au is taken from the Johnson and Christy’s measured data [27] which is widely used in literatures.
  • Perfectly matched layer (PML) absorbing boundaries are used to absorb the radiative photons that reaches the boundary of the calculated region (both propagating photons in the silicon waveguide and scattered photons outside the light source) with minimal reflections.
  • a high mesh FDTD with a stability factor of 0.95 is applied, where several extra high mesh boxes are added with the minimum mesh size of 0.25 nm to get further improvement in accuracy.
  • Transmission box is added around the tunnel junction to calculates the power out of the box of monitors.
  • the resistance of 0.1-10 ohm.cm of doped silicon is used according to example embodiments because it ensures light emission [11], and low propagation losses for MIS junctions. All material parameters are obtained from standard materials library in Lumerial FDTD software. Heavier silicon doping concentration will bring higher tunneling current density (emission intensity) in MIS junction as well as larger doping absorption loss.
  • the influence of heavily doped silicon on optical output performance is analyzed according to various example embodiments. In order to determine the optical properties of the heavily doped silicon, Drude formalism is used [28-30]:
  • N is the free carrier concentration per cm 3
  • e is the elementary charge
  • f 0 is the vacuum permittivity
  • m * is the effective mass and taken as 0.273 mo
  • mo is the electron mass.
  • a heavily doped concentration of N 10 19 cm 3 and 10 20 cm 3 in n-typed silicon are used in example embodiments.
  • the corresponding effective refractive index of the doped silicon in the operating wavelength range of lpm to 2 pm are presented in the FIG. 16.
  • the normalized LDOS, extraction efficiency and normalized extraction power corresponding to different doping concentrations are shown in FIG. 17. It should be noted that the change of current density is ignored and only the possible impact of the change of refractive index (including real part and imaginary part) brought by the doping on device performance is considered. It can be seen that when the doping concentration changes from 10 16 to 10 19 cm 3 , these three performance indicators become lightly worse with the increase of the doping concentration, under the premise of ignoring the change of current density. Even when the doping concentration reaches 10 20 cm 3 , the normalized extraction power only changes from 7700 to 6200. The resonance peak remains obvious seen at this very high doping concentration.
  • the heavily doping concentration of the n-type silicon does not significantly reduce device performance, but with the current density increasing significantly. Therefore, in order to enhance the emission intensity of the light source in the actual processing, higher silicon doping concentration can be recommended for the light source, while lower for the silicon waveguide for the low transmission loss. That is, in a preferred embodiment the doping concentration is varied along the silicon waveguide/source - higher at the tunnel junction area (below the antenna) and lower at either side of the tunnel junction area.
  • the general manufacturing processes of the key parts (nano-antenna enhanced tunneling junction) of the device according to an example embodiment includes generally providing a metal antenna layer, providing a doped semiconductor waveguide layer; and providing an insulator tunneling layer sandwiched between the metal antenna layer and the doped semiconductor waveguide layer to form a tunneling junction of the MIS structure; wherein the metal antenna layer confines plasmons excitable in the tunneling junction; and wherein the doped semiconductor waveguide layer couples photons excited by the plasmons for propagation in the doped semiconductor waveguide.
  • the fabrication method comprises: a: Pre-clean SOI wafer + native oxide removed b: photoresist (PR) coating + ridge etching (electron-beam lithography (EBL)+etching). c: S1O2 deposition (pulsed laser deposition (PLD)+annealing/atomic layer deposition (ALD)). d: PR removed and re-deposit 3nm S1O2 (PLD/ALD).
  • PR coating-i- alignment mark f sacrificed oxide etch + PLD/ALD re-deposit 2nm S1O2 (protrusion structure is defined)
  • g PR coating+alignment mark + ridge etching (EBL+etching) (nano-antenna structure connected with top strip electrode is defined)
  • h E- beam evaporator deposit Au/Cr/Ti (30nm/lnm) + Lift off.
  • a metal-insulator- semiconductor, MIS, structure comprising a metal antenna layer, a doped semiconductor waveguide layer; and an insulator tunneling layer sandwiched between the metal antenna layer and the doped semiconductor waveguide layer to form a tunneling junction of the MIS structure; wherein the metal antenna layer confines plasmons excitable in the tunneling junction; and wherein the doped semiconductor waveguide layer couples photons excited by the plasmons for propagation in the doped semiconductor waveguide.
  • the doped semiconductor waveguide may provide directional transmission of TM mode.
  • a length of the metal antenna layer along the doped semiconductor layer may be selected to tune a resonant frequency of the MIS structure.
  • the metal antenna layer may be sandwiched between a bump portion of the metal antenna layer and a junction portion of the doped semiconductor waveguide layer.
  • the bump portion of the metal antenna layer may protrude a main body of the metal antenna layer in a direction towards the doped semiconductor waveguide layer.
  • a thickness of the insulator tunneling layer adjacent the bum portion of the metal layer antenna may be large enough to allow most of a tunneling current through the bump portion of the metal antenna layer and the junction portion of the doped semiconductor waveguide layer.
  • the bump portion may be at a center of the main body of the metal antenna layer along the doped semiconductor waveguide.
  • the MIS structure may comprise a first electrode electrically coupled to the metal antenna layer and a second electrode coupled to the doped semiconductor waveguide layer.
  • the first electrode may be connected at a center of the metal antenna layer along the doped semiconductor waveguide.
  • the doped semiconductor waveguide layer may comprise n-Si, p-Si, S1 3 N 4 , SiC etc.
  • the metal antenna layer may comprise Ag, Au, Cu, A1 etc.
  • the insulator tunneling layer may comprise AI 2 O 3 , S1O 2 , hBN etc.
  • the MIS structure may be configured as a light source.
  • the MIS structure may be configured as a light detector.
  • a method of generating light using the metal-insulator- semiconductor, MIS, structure of the above described embodiment is provided.
  • a method of detecting light using the metal-insulator-semiconductor, MIS, structure of the above described embodiment is provided.
  • the light source according to example embodiments can be implemented as part of functionality programmed into any of a variety of circuitry, including programmable logic devices (PLDs), such as field programmable gate arrays (FPGAs), programmable array logic (PAL) devices, electrically programmable logic and memory devices and standard cell-based devices, as well as application specific integrated circuits (ASICs).
  • PLDs programmable logic devices
  • FPGAs field programmable gate arrays
  • PAL programmable array logic
  • ASICs application specific integrated circuits
  • the on-chip silicon light source according to the example embodiments described herein have input power due to the very small device size, which may introduce a lower signal-to-noise ratio.
  • this can be addressed in different embodiments by increasing the effective section area of the active region, for example by using low defect and high stability barrier material, increasing the doping concentration of semiconductor in the active region or multiple antennas in series.
  • An alternative way is to use larger planar tunnel junction, or to use high- quality single-crystalline nanocrystals as the metal material.
  • the main advantage in such embodiments is that the junction area can be arbitrarily amplified, however, the high ohmic loss and inefficient plasmonic coupling can greatly reduce the effective application of the input power of the device, and the modulation rate is also limited to MHz because of the large junction area in their device.
  • high LDOS and radiation efficiency can be obtained by the using of high-quality atomic-level nanoantenna. This can reduce the input power requirement to a certain extent, noting that because of using of edge to edge configuration as an optical antenna, the active area is still very small and the growth process may not meet the needs of large-scale applications.
  • the doped semiconductor waveguide layer is not limited to n-Si, but can comprise p-Si, S13N4, SiC etc.
  • the metal antenna layer is not limited to Ag, but can comprise Au, Cu, A1 etc.
  • the insulator tunneling layer is not limited to S1O 2 , but can comprise AI 2 O 3 , Hexagonal boron nitride (hBN) etc.

Abstract

L'invention concerne une structure métal-isolant-semi-conducteur, MIS, un procédé de fabrication de la structure MIS, un procédé de génération de lumière à l'aide de la structure MIS, et un procédé de détection de lumière à l'aide de la structure MIS. La structure MIS comprend une couche d'antenne métallique, une couche de guide d'onde à semi-conducteur dopée ; et une couche à effet tunnel d'isolant prise en sandwich entre la couche d'antenne métallique et la couche de guide d'onde à semi-conducteur dopée pour former une jonction à effet tunnel de la structure MIS ; la couche d'antenne métallique confinant des plasmons pouvant être excités dans la jonction à effet tunnel ; et la couche de guide d'onde à semi-conducteur dopée couplant des photons excités par les plasmons pour une propagation dans le guide d'onde à semi-conducteur dopé.
PCT/SG2020/050195 2019-04-09 2020-03-31 Structure métal-isolant-semi-conducteur WO2020209791A1 (fr)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030179974A1 (en) * 2002-03-20 2003-09-25 Estes Michael J. Surface plasmon devices
US20090273820A1 (en) * 2008-03-24 2009-11-05 Dionne Jennifer A Plasmostor: a-metal-oxide-si field effect plasmonic modulator
US20170254952A1 (en) * 2016-03-01 2017-09-07 National University Of Singapore Highly efficent on-chip direct electronic-plasmonic transducers

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030179974A1 (en) * 2002-03-20 2003-09-25 Estes Michael J. Surface plasmon devices
US20090273820A1 (en) * 2008-03-24 2009-11-05 Dionne Jennifer A Plasmostor: a-metal-oxide-si field effect plasmonic modulator
US20170254952A1 (en) * 2016-03-01 2017-09-07 National University Of Singapore Highly efficent on-chip direct electronic-plasmonic transducers

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
GOKTAS H. ET AL.: "Electrical-driven Plasmon Source on Silicon based on Quantum Tunneling", ACS PHOTONICS, vol. 5, no. 12, 2 November 2018 (2018-11-02), pages 4928 - 4936, XP055748288, DOI: 10.1021/acsphotonics.8b01106 *

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