Bulletin of the American Physical Society
APS March Meeting 2018
Volume 63, Number 1
Monday–Friday, March 5–9, 2018; Los Angeles, California
Session E11: Dopants and Defects in Semiconductors - Experimental techniquesFocus
|
Hide Abstracts |
Sponsoring Units: DMP DCOMP FIAP Chair: Nicholas Jungwirth, Cornell Univ Room: LACC 303A |
Tuesday, March 6, 2018 8:00AM - 8:36AM |
E11.00001: Ion Beam Modification of 2-Dimensional Nanomaterials Invited Speaker: Cory Cress The preponderance of surface atoms in 2-dimensional (2D) nanomaterials makes them particularly accessible for interaction with directed ion beams. When coupled with the wide range of experimentally accessible ion energies and species, we are afforded with a highly tailored 2D nanomaterial modification toolkit possible of achieving controlled surface functionalization, substitutional doping, and vacancy/defect concentration profiles. In this presentation we discuss recent work employing hyperthermal ions (5 – 250 eV) to both substitutionally dope graphene (N ions) and to strain few-layer graphene with defects (Ar ions). We will also share preliminary work using hyperthermal ions and focused He ion beams (Orion NanoFab) to spatially control the doping and defect levels in transition-metal dichalcogenides and black phosphorous. We will discuss insights spanning the entire ion beam processing cycle from sample preparation, to processing, to physical/chemical analysis of ion beam treated films. Finally, we will conclude by outlining the current challenges and future prospects of this emerging field. |
Tuesday, March 6, 2018 8:36AM - 8:48AM |
E11.00002: Infrared Spectroscopy of Dilute Impurities in High-Purity Silicon Vladimir Martinez, Berik Uzakbaiuly, David Tanner Silicon has uses as test-mass material for future gravitational-wave detectors and in high-resolution infrared spectroscopy in astronomy. The effectiveness of these devices relies heavily on the transparency of Si in the infrared region. The temperature-dependent infrared transmission has been measured for high-purity silicon samples with a range of impurity concentrations, ranging from below 1012 to 1015 per cc. Measurements were made in a frequency range from 10–10,000 cm-1 and temperatures from 10–300K. The mid infrared region (600–2000 cm-1) is dominated by multiphonon absorption, while the far infrared (10–600 cm-1) and the near infrared (2000–9000 cm-1) are transparent with the exception of absorption lines in the far infrared caused by residual impurities. These absorption lines are mostly due to hydrogen-like transitions in phosphorus and boron and will have a significant effect on the optimal operation of the Si device. With increasing temperature, we are able to observe thermal population of excited states of the impurity atom and eventually of the continuum. Using the results of our transmission spectra we are able to determine the concentration of the impurities in the sample. |
Tuesday, March 6, 2018 8:48AM - 9:00AM |
E11.00003: Incorporating Magnetic Resonance Into a Wafer Probing Station Duane McCrory, Mark Anders, Ryan Waskiewicz, Patrick Lenahan, Jason Campbell, Jason Ryan, Aivars Lelis We have incorporated very high sensitivity electrically detected magnetic resonance (EDMR) detection in a wafer probing station. We believe this development may be of significant utility because the family of electron paramagnetic resonance (EPR) has unrivaled analytical power in the identification of point defects in semiconductors and insulators. EDMR has all of the analytical power of conventional EPR, plus enormously enhanced sensitivity, allowing measurements to be made on near nanoscale devices. It also has the capability to be exclusively sensitive to only those point defects which directly affect the performance of solid state devices such as: metal oxide semiconductor field effect transistors (MOSFETs), bipolar junction transistors, p-n junctions, and many other devices. Wafer-Level EDMR (WLEDMR) allows for resonance based measurements on a wide variety of devices in fully processed wafers with high sensitivity. This sensitivity allows for, what is to the best of our knowledge, the first demonstration of spatially resolved EDMR across the surface of a MOSFET. |
Tuesday, March 6, 2018 9:00AM - 9:12AM |
E11.00004: Atomic-resolution STM/STS study of Bi atoms implanted in Si(001) Steven Schofield, Neil Curson, Manuel Siegl, Kitiphat Sinthiptharakoon The quantum states formed by atomic point defects and dopant atoms in semiconductors are of renewed current interest because these systems hold the potential to become the active components of nanoscale electronic devices. Scanning tunnelling microscopy and spectroscopy (STM/STS) provide the unique ability to resolve in real-space, and as a function of energy, the quantum states of individual defects and dopants in semiconductors. In this talk we will present a low temperature STM/STS investigation of Si(001) samples implanted with Bi atoms. We observe a new defect state that we associate with the implanted Bi atoms and we will present a discussion of the properties of these features. |
Tuesday, March 6, 2018 9:12AM - 9:24AM |
E11.00005: The analyses of multi optical method on the structural evolution of B implanted ultra-shallow layers FENG-MING CHANG, Fu-Ying Lee, ZONG-ZHE WU, Cheng-Ta Wu, Shiu-Ko JangJian, Yu-Ming Chang, Kuang Yao Lo Ion implantation technology plays an important role in next generation Si-based devices. We provide multi optical method, including UV Raman, X-ray photoemission spectroscopy (XPS), X-ray Absorption Near Edge Structure (XANES), reflective second harmonic generation (RSHG) to inspect the structural evolution of B-implanted ultra-shallow layers (USL) in a quantification way rather than the traditional measurement such as thermal wave and sheet resistance measurement which have exploring depth of several micrometers. According to XPS spectra, the B-B bond disappeared at the optima condition of beam current, which strongly agreed with the results of UV Raman that exhibited the most effective Si-B bond at the same condition. The results reveal the influence of beam current on the implantation process. Besides, the quality distinguish between ultra-low energy B implantation on room-temperature substrate (R) and cold-temperature substrate (C) samples via nano-second laser annealing were analyzed by multi optical method. The homogeneous amorphous layer, well-restructure and stable chemical states after laser annealing were observed on C samples. This optical method open a window to monitor further USL. |
Tuesday, March 6, 2018 9:24AM - 9:36AM |
E11.00006: Echo Trains in pulsed electron spin resonance Stefan Weichselbaumer, Petio Natzkin, Christoph Zollitsch, Martin Brandt, Rudolf Gross, Hans Huebl Strong coupling between a spin ensemble and a microwave resonator is essential for a coherent exchange of excitation. While most experiments today focus on continuous wave experiments, we investigate the dynamics of the coupled spin-resonator system in the strong coupling regime. In particular, we use Hahn echos and observe multiple unexpected echo signatures after the first conventional echo. Experimentally, we study an ensemble of phosphorus donor spins in isotopically purified 28Si with ms coherence times. With a static magnetic field, we tune their transition frequency into resonance with a superconducting lumped element microwave resonator. We present experimental data within and outside the strong coupling regime and discuss a model predicting and corroborating the amplitude evolution of the echos based on the echo separation time, the dephasing rate of the spin ensemble, and the linewidth of the microwave resonator. |
Tuesday, March 6, 2018 9:36AM - 9:48AM |
E11.00007: Long-distance excitation of nitrogen-vacancy centers in diamond via surface spin waves Daisuke Kikuchi, Dwi Prananto, Kunitaka Hayashi, Abdelghani Laraoui, Norikazu Mizuochi, Mutsuko Hatano, Eiji Saitoh, Yousoo Kim, Carlos Meriles, Toshu An Coherent communication over mesoscale distances is a necessary condition for the application of solid-state spin qubits to scalable quantum information processing. Among other routes under study, one possibility entails the use of magnetostatic surface spin waves (MSSW) coupled to shallow paramagnetic defects in wide-bandgap semiconductors. Here we present the use of room-temperature magnetostatic surface spin waves (MSSWs) propagating in yttrium iron garnet (YIG) as a medium to coherently manipulate spin in a diamond with nitrogen-vacancy (NV) centers at a distant far away from a microwave source. We demonstrated a transport spanning over 3 mm which attributed to the robustness of MSSW and the large spin-wave diffusion length of YIG[1]. With NV spins as a local sensor, we find that the MSSW couples resonantly, and the amplitude of NV spins grow linearly with the applied microwave power, suggesting that this approach could potentially be extended to amplify the signal from neighboring spin qubits by several orders of magnitude. [1] D.Kikuchi, D. Prananto, K. Hayashi, A. Laraoui, N. Mizuochi, M. Hatano, E. Saitoh, Y. Kim, C. A. Meriles, and T. An, Appl. Phys. Express 10, 103004 (2017). |
Tuesday, March 6, 2018 9:48AM - 10:00AM |
E11.00008: Near Zero-Field Magnetoresistance and High and Ultra Low Frequency Electrically Detected Magnetic Resonance in 4H-SiC p-n Junctions Elias Frantz, Ryan Waskiewicz, Brain Manning, Patrick Lenahan We have investigated 4H-SiC p-n junction diodes with X-band (~10GHz) and ultra-low frequency (~10MHz) electrically detected magnetic resonance (EDMR) and compared the EDMR response to the near zero-field magnetoresistance (MR) of these devices. Both the EDMR and the MR involve spin-dependent recombination within the junction depletion region. These measurements were made over a wide range of junction forward bias. The EDMR measurements involve current change via resonance induced changes in triplets to singlets, whereas MR involves singlet – triplet mixing. The study involves several devices with significantly different doping. The EDMR and MR comparisons provide some physical insight into the MR. Development of a fundamental understanding of the near-zero field MR may be of real technological significance as the response can be exploited in a new class of magnetometers designed for deep space applications. |
Tuesday, March 6, 2018 10:00AM - 10:12AM |
E11.00009: Nanoscale imaging of surface acoustic waves with stroboscopic scanning x-ray diffraction microscopy Samuel Whiteley, F. Joseph Heremans, David Awschalom, Martin Holt In quantum electronics the manipulation of strain near isolated point defects and engineered structures is central to harnessing the potential of solid-state qubits for hybrid quantum systems and nanoscale sensing. While lattice strain can be used both statically and dynamically to tune quantum energy levels and engineer hybrid system response, the direct observation of nanoscale strain fields induced near quantum defects is extremely challenging as this strain is localized near a defect potentially microns from surface and varying in time. We report preliminary results of a stroboscopic Scanning X-ray Diffraction Microscopy (s-SXDM) imaging approach using 10 keV photons focused to a ~20 nm FWHM beam waist at the CNM Hard X-ray Nanoprobe, in which ~30 ps x-ray pulses from the APS were synchronized to a Surface Acoustic Wave (SAW) launcher in order achieve static time domain and phase sensitive Bragg diffraction imaging at radio frequencies with nanoscale spatial resolution. We use this technique to simultaneously map near-surface microstructure, atomic fluorescence, and acoustically induced lattice curvatures generated by interdigitated transducers fabricated on 4H-SiC which hosts vacancy related spin defects for quantum sensing and information. |
Tuesday, March 6, 2018 10:12AM - 10:24AM |
E11.00010: Coherent mechanical driving of spin ensembles in 4H-SiC using a gaussian surface acoustic wave resonator Gary Wolfowicz, Samuel Whiteley, Christopher Anderson, Alexandre Bourassa, Gerwin Koolstra, Kevin Satzinger, F. Joseph Heremans, David Schuster, Andrew Cleland, David Awschalom Silicon carbide (SiC) has recently emerged as a promising host material for spin qubits. In particular, divacancies and silicon vacancies in 4H-SiC have been shown to have similar optical and spin properties to the nitrogen vacancy center in diamond. SiC also provides wafer-scale growth and mature fabrication processes, as well as being a piezoelectric material allowing for design of electromechanical devices. Here we demonstrate design, fabrication and characterization of a gaussian surface acoustic wave resonator (SAW) using a sputtered AlN epilayer on top of 4H-SiC, which is used to drive strain-induced coherent mechanical control of divacancy spin ensembles near the surface. This enables demonstration of Autler-Townes splitting and coherent Rabi driving on all c-axis (hh, kk, and PL6) defects. We further utilize the Autler-Townes effect to map the gaussian SAW mode shape, measuring a transverse beam waist of only 40 µm full width at half maximum (12 µm wavelength). This work provides the basis for further spin-mechanical hybrid systems, and in particular toward applications such as quantum communication and transduction. |
Tuesday, March 6, 2018 10:24AM - 10:36AM |
E11.00011: Contactless mobility measurements using two-photon excitation and a terahertz probe Jared Wahlstrand, Edwin Heilweil Time-dependent THz spectroscopy is widely used for measuring mobility in novel electronic materials, in which the mobility is often adversely affected by defects and unintentional dopants [1]. One of its great advantages over other techniques is that it does not require ohmic contacts. Recently, it was shown that the mobility values extracted from optical-pump, THz-probe measurements are consistent with contact-based Hall Van der Pauw measurements [2]. However, because of the sub-micron penetration depth of above band gap light in direct bandgap semiconductors, the carrier densities required to produce a measurable change in THz transmission are high enough that the mobility can be reduced by electron-electron scattering. Below gap two-photon excitation offers an alternative since it is able to excite carriers throughout the entire semiconductor thickness at once, resulting in a significantly lower carrier density for the same amount of THz absorption. We present results for ZnSe and GaP and compare the THz measurements to conventional z-scan and pump absorption on the same samples. |
Tuesday, March 6, 2018 10:36AM - 10:48AM |
E11.00012: Optically Driven Charge State Switching of SiC Defects David Golter, Chih-Wei Lai Defects have been identified in silicon carbide (SiC) with long spin coherence times and electronic structures similar to the diamond nitrogen vacancy (NV), but in a host material that may be more conducive to future wafer-scale quantum technologies. We focus on divacancies and NVs in 4H-SiC which have optical transitions ranging from 1070 nm to 1240 nm, closer to telecom wavelengths. We use photoluminescence excitation measurements of divacancy ensembles to investigate an energy dependent suppression and recovery of the fluorescence, observing a threshold energy of about 1.3 eV that varies for different divacancy types. We attribute these effects to optically driven switching between different charge states [1]. Additionally we explore NVs in SiC, taking the first steps towards microwave and optical control of single defect spins. |
Tuesday, March 6, 2018 10:48AM - 11:00AM |
E11.00013: The photoelastic coefficient P12 of H+ implanted GaAs as a function of defect density Andrey Baydin, Halina Krzyzanowska, Rustam Gatamov, Joy Garnett, Norman Tolk The photoelastic phenomenon has been widely investigated as a fundamental elastooptical property of solids. This effect has been applied extensively to study stress distribution in lattice-mismatched semiconductor heterostructures. GaAs based optoelectronic devices used in space probes are subject to damage arising from energetic proton irradiation. For that reason, the effect of proton irradiation on photoelastic coefficients of GaAs is of primary importance to space applied optoelectronics. However, there yet remains a lack of systematic studies of energetic proton induced changes in the photoelastic properties of bulk GaAs. In this work, we present the depth-dependent photoelastic coefficient P12 profile in non-annealed H+ implanted GaAs obtained from the analysis of the time-domain Brillouin scattering spectra. The depth-dependent profiles are found to be broader than the defect distribution profiles predicted by Monte Carlo simulations. This fact indicates that the changes in photoelastic coefficient P12 depend nonlinearly on the defect concentrations created by the hydrogen implantation. These studies provide insight into the spatial extent to which defects influence photoelastic properties of GaAs. |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700