CMOS‐Compatible Electronic–Plasmonic Transducers Based on Plasmonic Tunnel Junctions and Schottky Diodes

Abstract

plasmonic metals, such as Au and Ag, that are not CMOS compatible. [8] Here, we report an all-electrical, CMOS-compatible electronic-plasmonic transducer based on an Al-AlO X -Cu tunnel junction as the plasmon source, a Si-Cu Schottky diode as the plasmon detector, both connected by a Cu plasmonic strip waveguide. These electronic-plasmonic transducers do not require bulky off-chip components and are useful for future on-chip applications where it is vital to interface plasmonics with microelectronics. [1,9] Often, SPPs are excited by optical means, which requires momentummatching elements such as gratings or prisms. [10] One approach to realize on-chip excitation of SPPs is to miniaturize the light sources where first an electrical signal is converted to photons which then couple to SPPs. [3,11,12] In this context of miniaturization, metalinsulator-metal tunnel junctions (MIM-TJs) are interesting because they can be used as electrically driven plasmon sources where SPPs are directly excited via inelastic tunneling of electrons. [13][14][15] The potential of such plasmonic tunnel junctions has been explored in terms of two-photon emission, [16] above threshold emission (where the emitted photons have higher energy than the applied bias), [17,18] and nonlinear effects [19] have been demonstrated. It is also possible To develop methods to generate, manipulate, and detect plasmonic signals by electrical means with complementary metal-oxide-semiconductor (CMOS)-compatible materials is essential to realize on-chip electronicplasmonic transduction. Here, electrically driven, CMOS-compatible electronic-plasmonic transducers with Al-AlO X -Cu tunnel junctions as the excitation source of surface plasmon polaritons (SPPs) and Si-Cu Schottky diodes as the detector of SPPs, connected via plasmonic strip waveguides of Cu, are demonstrated. Remarkably, the electronic-plasmonic transducers exhibit overall transduction efficiency of 1.85 ± 0.03%, five times higher than previously reported transducers with two tunnel junctions (metal-insulatormetal (MIM)-MIM transducers) where SPPs are detected based on optical rectification. The result establishes a new platform to convert electronic signals to plasmonic signals via electrical means, paving the way toward CMOS-compatible plasmonic components.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/smll.202105684.

Low voltage-driven, high-performance TiO2 thin film transistors with MHz switching speed

“…Another layer of Al 2 O 3 (∼8 nm) was chosen as the insulating oxide due to its excellent lm quality and large bandgap. [18][19][20] Fig. 1b illustrates the corresponding cross-section view, where Al was selected as the contact metal since a good ohmic contact can be formed between Al and TiO 2 without annealing, while Pt is used as a capping layer to prevent the Al layer from oxidization.…”

Nanoscale Electrically Driven Light Source Based on Hybrid Semiconductor/Metal Nanoantenna

“…9,29,30 The opening possibility to use tunnel junctions with a silicon electrode (even provided that the counterpart electrode is metallic) seems especially attractive for prospective implementation of nanoscale LEIT sources and receivers of optical radiation. 31 Replacing one of the electrodes with Si or CMOS-compatible materials would pave the way toward CMOS-compatible electrically driven sources of light. 32−34 Scanning tunneling microscopy (STM) provides another opportunity to realize an effective MIM (or MIS) LEIT system with greatly amplified LDOS.…”

“…In another notable work an optical radiation source consisting of a Yagi–Uda antenna coupled with a MIM junction was investigated; the authors demonstrated that such a system can overcome the limitations associated with Joule heating. Recent studies have also shown that high quantum efficiency of LEIT radiation can be achieved with metal–insulator–semiconductor (MIS) structures. ,, The opening possibility to use tunnel junctions with a silicon electrode (even provided that the counterpart electrode is metallic) seems especially attractive for prospective implementation of nanoscale LEIT sources and receivers of optical radiation . Replacing one of the electrodes with Si or CMOS-compatible materials would pave the way toward CMOS-compatible electrically driven sources of light. − …”

Tunable Nanoplasmonic Photodetectors

“…26 Also, while our material combination is not suitable for standard silicon processes, CMOS-compatible plasmonic devices have been demonstrated. 27,28 A bigger limitation, in terms of possible applications, is the detection efficiency which is rather low compared to standard photodetectors based on silicon. We calculate the detection efficiency by dividing the photocurrent by the total incoming power of our laser light, corrected by the size of the laser spot and the antenna absorption cross section.…”

“…Plasmonic photodetectors at blue wavelengths are also feasible by employing different materials, like aluminum or silver . Also, while our material combination is not suitable for standard silicon processes, CMOS-compatible plasmonic devices have been demonstrated. , …”