Oleg Shtempluck

Technion - Israel Institute of Technology, H̱efa, Haifa, Israel

Are you Oleg Shtempluck?

Claim your profile

Publications (46)112.47 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Initial or residual stress plays an important role in nano-electronics. Valley de- generacy in silicon nanowires (SiNWs) is partially lifted due to built-in stresses and, consequently, electron-phonon scattering rate is reduced and device mobility and per- formance are improved. In this study we use a non-linear model describing the force- deflection relationship to extract the Young's modulus, the residual stress, and the crystallographic growth orientation of SiNW beams. Measurements were performed on suspended doubly clamped SiNWs subjected to atomic force microscopy (AFM) 3-point bending constraints. The nanowires comprised different growth directions and two SiO2 sheath thicknesses, and underwent different rapid thermal annealing pro- cesses. Analysis showed that rapid thermal annealing introduces compressive strains into the SiNWs and may result in buckling of the SiNWs. Furthermore, the core-shell model together with the residual stress analysis accurately describe the Young's modu- lus of oxide covered SiNWs, as well as the crystal orientation of the measured nanowires.
    Nano Letters 03/2015; 15(5). DOI:10.1021/nl5047939 · 12.94 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Optically induced self-excited oscillations of suspended mirror of a fully on-fiber optomechanical cavity are experimentally demonstrated. The cavity is fabricated by patterning a suspended metallic mirror on the tip of an optical fiber and by introducing a static reflector in the fiber. We discuss the use of on-fiber optomechanical cavities for sensing applications. A theoretical analysis evaluates the sensitivity of the proposed sensor operating in the region of the self-excited oscillations. The results are compared with the experimental data and with the sensitivity that is achievable when the oscillations are driven by an external oscillatory force.
    Journal of Microelectromechanical Systems 06/2014; 23(3):563-569. DOI:10.1109/JMEMS.2013.2290061 · 1.92 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Humidity plays an important role in molecular electronics. It facilitates charge movement on top of dielectric layers and modifies the device transfer characteristics. Using two different methods to probe temporal charge redistribution on the surface of dielectrics, we were able to extract the surface humidity for the first time. The first method is based on the relaxation time constants of the current through carbon nanotube field-effect transistors (CNTFETs), and the second is based on electric force microscopy (EFM) measurements. Moreover, we found that applying external gate biases modifies the surface humidity. A theoretical model based on dielectrophoretic attraction between the water molecules and the substrate is introduced to explain this observation, and the results support our hypothesis. Furthermore, it is found that upon the adsorption of two to three layers of water the surface conductivity saturates.
    ChemPhysChem 12/2012; 13(18). DOI:10.1002/cphc.201200628 · 3.36 Impact Factor
  • Source
    Gil Bachar, Ilya Baskin, Oleg Shtempluck, Eyal Buks
    [Show abstract] [Hide abstract]
    ABSTRACT: We present a novel design of a superconducting nanowire single photon detector (SNSPD) fabricated on a core of a single mode optical fiber. The proposed design allows high overlap between the fiber light mode and the detector, and consequently, our fabricated devices can remain small in dimension and maintain speed of operation, without scarifying the detection efficiency. The on-fiber fabrication method is detailed, together with experimental results. The proposed method can be exploited in the future for the fabrication of other fiber coupled devices.
    Applied Physics Letters 11/2012; 101(26). DOI:10.1063/1.4773305 · 3.52 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A fully on-fiber optomechanical cavity is fabricated by patterning a suspended metallic mirror on the tip of an optical fiber. Optically induced self-excited oscillations of the suspended mirror are experimentally demonstrated. We discuss the feasibility of employing on-fiber optomechanical cavities for sensing applications. A theoretical analysis evaluates the sensitivity of the proposed sensor, which is assumed to operate in the region of self-excited oscillations, and the results are compared with the experimental data. Moreover, the sensitivity that is obtained in the region of self-excited oscillations is theoretically compared with the sensitivity that is achievable when forced oscillations are driven by applying an oscillatory external force.
    Journal of Microelectromechanical Systems 10/2012; · 1.92 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, we present a quantitative method to measure charge density on dielectric layers using electrostatic force microscopy. As opposed to previous reports, our method, which is based on force curve measurements, does not require preliminary knowledge of the tip-sample capacitance and its derivatives. Using this approach, we have been able to quantify lateral and temporal SiO2 surface charge distribution and have unveiled a gate-induced charge redistribution mechanism which takes place in the vicinity of grounded electrodes. We argue that this mechanism constitutes a dominant factor in the hysteresis phenomenon, which is frequently observed in the transfer characteristics of nano-scale devices.
    Journal of Applied Physics 10/2012; 112(8). DOI:10.1063/1.4761981 · 2.19 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Carbon nanotube field-effect transistors (CNT FETs) have many possible applications in future nanoelectronics due to their excellent properties. However, one of the major challenges regarding their performance is the noticeable gate hysteresis which is often displayed in their transfer characteristics. The hysteresis phenomenon is often attributed to water-mediated charge transfer between the CNT and the dielectric layer or the CNT and the water layer itself. In this study, we implement the usage of current versus time measurements in addition to the traditional transfer characteristics to accurately extract the time constants of the hysteresis of suspended and on-surface CNT FETs. Following a thorough study, we provide experimental evidence that the hysteresis phenomenon of suspended CNT FETs, as well as of on-surface CNT FETs which operate at low gate voltage regimes (|Vg|<3 V), is based on gate-induced, water-assisted redistribution of mobile charge on the SiO2 surface, and is not related to charge injection from the CNT itself. Our model is confirmed by an electronic-force-microscopy-based measurement technique which enables us to quantify the temporal surface charge distribution while measuring CNT currents.
    Physical review. B, Condensed matter 09/2012; 86(11). DOI:10.1103/PhysRevB.86.115444 · 3.66 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Semiconducting nanowires have been pointed out as one of the most promising building blocks for submicron electrical applications. These nanometer materials open new opportunities in the area of post-planar traditional metal-oxide-semiconductor devices. Herein, we demonstrate a new technique to fabricate horizontally suspended silicon nanowires with gate-all-around field-effect transistors. We present the design, fabrication and electrical measurements of a high performance transistor with high on current density (∼150 μA μm(-1)), high on/off current ratio (10(6)), low threshold voltage (∼ - 0.4 V), low subthreshold slope (∼100 mV /dec) and high transconductance (g(m) ∼ 9.5 μS). These high performance characteristics were possible due to the tight electrostatic coupling of the surrounding gate, which significantly reduced the Schottky-barrier effective height, as was confirmed experimentally in this study.
    Nanotechnology 09/2012; 23(39):395202. DOI:10.1088/0957-4484/23/39/395202 · 3.67 Impact Factor
  • Source
    D. Yuvaraj, M. B. Kadam, Oleg Shtempluck, Eyal Buks
    [Show abstract] [Hide abstract]
    ABSTRACT: We study an optomechanical cavity, in which a buckled suspended beam serves as a mirror. The mechanical resonance frequency of the beam obtains a minimum value near the buckling temperature. Contrary to the common case, in which self-excited oscillations of the suspended mirror are optically induced by injecting blue detuned laser light, in our case self-excited oscillations are observed with red detuned light. These observations are attributed to a retarded thermal (i.e. bolometric) force acting on the buckled mirror in the inwards direction (i.e. towards to other mirror). With relatively high laser power other interesting effects are observed including period doubling of self-excited oscillations and intermode coupling.
    Journal of Microelectromechanical Systems 07/2012; DOI:10.1109/JMEMS.2012.2226931 · 1.92 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We present a new approach to the induction detection of electron spin resonance (ESR) signals exploiting the nonlinear properties of a superconducting resonator. Our experiments employ a yttrium barium copper oxide (YBCO) superconducting stripline microwave (MW) resonator integrated with a microbridge. A strong nonlinear response of the resonator is thermally activated in the microbridge when exceeding a threshold in the injected MW power. The responsivity factor characterizing the ESR-induced change in the system's output signal is about 100 times larger when operating the resonator near the instability threshold, compared to the value obtained in the linear regime of operation. Preliminary experimental results, together with a theoretical model of this phenomenon are presented. Under appropriate conditions nonlinear induction detection of ESR can potentially improve upon the current capabilities of conventional linear induction detection ESR.
    Applied Physics Letters 04/2012; 101(2). DOI:10.1063/1.4734500 · 3.52 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We experimentally study forced and self-excited oscillations of an optomechanical cavity, which is formed between a fiber Bragg grating that serves as a static mirror and a freely suspended metallic mechanical resonator that serves as a moving mirror. In the domain of small amplitude mechanical oscillations, we find that the optomechanical coupling is manifested as changes in the effective resonance frequency, damping rate, and cubic nonlinearity of the mechanical resonator. Moreover, self-excited oscillations of the micromechanical mirror are observed above a certain optical power threshold. A comparison between the experimental results and a theoretical model that we have recently derived and analyzed yields a good agreement. The comparison also indicates that the dominant optomechanical coupling mechanism is the heating of the metallic mirror due to optical absorption.
    Physical Review E 10/2011; 84(4 Pt 2):046605. DOI:10.1103/PhysRevE.84.046605 · 2.33 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Highly reproducible Nb/Al(AlOx)/Nb Josephson junction based direct current superconducting quantum interference devices (DC SQUID) were fabricated by three dimensional etching using focused ion beam. Hysteretic and non-hysteretic DC SQUID with critical current ranging from 25 to 1100 microampere were fabricated by varying the Al barrier and oxygen exposure time. The fabricated DC SQUIDs have shown periodic flux dependence with high modulation factor reaching a value of 92% at 4.2 K.
  • Source
    Stav Zaitsev, Oleg Shtempluck, Eyal Buks
    [Show abstract] [Hide abstract]
    ABSTRACT: Electron beam induced deposition of amorphous carbon finds several uses in microlithography, surface micromachining, and the manufacturing of micro- and nanomechanical devices. This process also occurs unintentionally in vacuum chambers of electron microscopes and interferes with normal image acquisition by reducing resolution and causing charging effects. In this work, we show that the resonance frequency of a micromechanical oscillator can be significantly affected by exposing it to a focused electron beam, which induces local carbonization on the surface of the oscillator, resulting in increase in the effective stress along the beam. This \emph{in-situ} carbonization can be utilized for analyzing the amount of residual organic contamination in vacuum chambers. In addition, the method described here allows post-fabrication fine tuning of mechanical resonance frequencies of individual oscillating elements.
    Sensors and Actuators A Physical 05/2011; 179. DOI:10.1016/j.sna.2012.02.039 · 1.94 Impact Factor
  • Source
    Eran Segev, Oren Suchoi, Oleg Shtempluck, Fei Xue, Eyal Buks
    [Show abstract] [Hide abstract]
    ABSTRACT: This study examined the voltage response of nanobridge-based direct-current superconducting quantum interference devices (dc-SQUIDs) fabricated on a Si3N4 membrane. Such a configuration may help in reducing 1/f noise, which possibly originates from substrate fluctuating defects. Results showed that the poor thermal coupling between the dc-SQUID and the substrate leads to a strong hysteretic response of the superconducting quantum interference device (SQUID) even though it is biased by an alternating current. In addition, when the dc-SQUID is biased near a threshold of spontaneous oscillations, the measured voltage has an intermittent pattern, which depends on the applied magnetic flux threading the loop of the SQUID.
    Applied Physics Letters 01/2011; 98(5):052504-052504-3. DOI:10.1063/1.3549767 · 3.52 Impact Factor
  • Source
    Eran Segev, Oren Suchoi, Oleg Shtempluck, Fei Xue, Eyal Buks
    [Show abstract] [Hide abstract]
    ABSTRACT: We study voltage response of nano-bridge based DC-SQUID fabricated on a Si\_{3}N\_{4} membrane. Such a configuration may help in reducing 1/f noise, which originates from substrate fluctuating defects. We find that the poor thermal coupling between the DC-SQUID and the substrate leads to strong hysteretic response of the SQUID, even though it is biased by an alternating current. In addition, when the DC-SQUID is biased near a threshold of spontaneous oscillations, the measured voltage has an intermittent pattern, which depends on the applied magnetic flux through the SQUID.
  • Source
    Eran Segev, Oren Suchoi, Oleg Shtempluck, Fei Xue, Eyal Buks
    [Show abstract] [Hide abstract]
    ABSTRACT: We study the metastable response of a highly hysteretic DC-SQUID made of a Niobium loop interrupted by two nano-bridges. We excite the SQUID with an alternating current and with direct magnetic flux, and find different stability zones forming diamond-like structures in the measured voltage across the SQUID. When such a SQUID is embedded in a transmission line resonator similar diamond structures are observed in the reflection pattern of the resonator. We have calculated the DC-SQUID stability diagram in the plane of the exciting control parameters, both analytically and numerically. In addition, we have obtained numerical simulations of the SQUID equations of motion, taking into account temperature variations and non-sinusoidal current-phase relation of the nano-bridges. Good agreement is found between experimental and theoretical results.
    Physical review. B, Condensed matter 07/2010; 83(10). DOI:10.1103/PhysRevB.83.104507 · 3.66 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In this work we study the sensitivity of the primary resonance of an electrically excited microresonator for the possible usage of a temperature sensor. We find a relatively high normalized responsivity factor Rf = || = 0.37 with a quality factor of ∼ 105. To understand this outcome we perform a theoretical analysis based on experimental observation. We find that the dominant contribution to the responsivity comes from the temperature dependence of the tension in the beam. Subsequently, Rf is found to be inversely proportional to the initial tension. Corresponding to a particular temperature, the tension can be increased by applying a bias voltage.
    Applied Physics Letters 05/2010; 96(20):203105-203105-3. DOI:10.1063/1.3431614 · 3.52 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We study superconducting stripline resonator (SSR) made of Niobium, which is integrated with a superconducting interference device (SQUID). The large nonlinear inductance of the SQUID gives rise to strong Kerr nonlinearity in the response of the SSR, which in turn results in strong coupling between different modes of the SSR. We experimentally demonstrate that such intermode coupling gives rise to dephasing of microwave photons. The dephasing rate depends periodically on the external magnetic flux applied to the SQUID, where the largest rate is obtained at half integer values (in units of the flux quantum). To account for our result we compare our findings with theory and find good agreement. Supplementary info at arXiv:0901.3133 . Comment: 5 pages and 5 figures, supplementary info at arXiv:0901.3133
    Physical review. B, Condensed matter 05/2010; 81(17):174525. DOI:10.1103/PhysRevB.81.174525 · 3.66 Impact Factor
  • Source
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We experimentally and numerically study a NbN superconducting stripline resonator integrated with a microbridge. We find that the response of the system to monochromatic excitation exhibits intermittency, namely, noise-induced jumping between coexisting steady-state and limit-cycle responses. A theoretical model that assumes piecewise linear dynamics yields partial agreement with the experimental findings.
    EPL (Europhysics Letters) 01/2010; 89(1):17003. DOI:10.1209/0295-5075/89/17003 · 2.27 Impact Factor