Modification of the omega-meson lifetime in nuclear matter

Information on hadron properties in the nuclear medium has been derived from the photoproduction of omega mesons on the nuclei C, Ca, Nb, and Pb using the Crystal Barrel/TAPS detector at the ELSA tagged photon facility in Bonn. The dependence of the omega-meson cross section on the nuclear mass number has been compared with three different types of models: a Glauber analysis, a Boltzmann-Uehling-Uhlenbeck analysis of the Giessen theory group, and a calculation by the Valencia theory group. In all three cases, the inelastic omega width is found to be 130-150 MeV/c(2) at normal nuclear matter density for an average 3-momentum of 1.1 GeV/c. In the rest frame of the omega meson, this inelastic omega width corresponds to a reduction of the omega lifetime by a factor approximately 30. For the first time, the momentum dependent omegaN cross section has been extracted from the experiment and is in the range of 70 mb.     

Nuclear orientation study of182Ta in 2H-TaS2

Quadrupole-interaction nuclear orientation experiments have been performed on¹⁸²Ta (j^π=3^?1; T_1/2=115d) in 2H-TaS₂. γ-anisotropies up to ～ 30 % have been observed at a temperature of ～ 8 mK, which, however, is only about half of the value expected taking into account known results of TDPAC measurements on¹⁸¹Ta in 2H-TaS₂. In principle, matrices of dichalcogenides could be well suited for nuclear quadrupole resonance on oriented nuclei (NQR-ON) experiments.     

Trace-analytical methods for monitoring contaminations in semiconductor-grade Si manufacturing

Generating systematic data on incoming materials, processes, production environments and products by contamination monitoring and analyis is the key element of quality assurance in semiconductor fabrication. To be able to match the analytical capabilities to the requirements of improving materials and processes, the level of sophistication of contamination monitoring and analysis systems must be higher than the expected demands in the fabrication line. The accuracy of each analytical method has to be cross-checked by different independent techniques. Accuracy, precision, power of detection, analysis time and expenses should always be tailored to the particular case. All monitoring methods must run under statistical process control. The methods described meet the analytical requirements of the near future in semiconductor grade silicon manufacturing.Glossary AAS Atomic Absorption Spectrometry - ADD Acid-mixture Drop Decomposition of the native oxide and, occasionally of Si surface due to given acid etchant mixtures such as HF+HNO₃ in order to preconcentrate dissolvable metallic impurities of the surface (c.f. MAD, VPD, WSSD) - AEM Analytical Electron Microscopy - AEPS Auger Electron Appearance Potential Spectroscopy (=APAES) - AES Auger Electron Spectroscopy - AFM Atomic Force Microscope - AM Acoustic Microscopy - AMS Accelerator Mass Spectrometry (Tandem-SIMS) - APIMS Atmospheric Pressure Ionization Mass Spectroscopy - ARAES Angle-Resolved Auger Electron Spectroscopy - ARUPS Angle-Resolved Ultraviolet Photoemission Spectroscopy - ATR-FTIR Attenuated Total Reflection Fourier Transform Infrared Spectroscopy - BEEM Ballistic Electron Emission Microscopy - BMD heat induced Bulk Micro-Defects in monocrystalline Si after a specified thermal process cycle, corresponding to SIO_x precipitates in monocrystalline Si [31] - BSE Back Scattered Electrons - CE Capillary Electrophoresis (cf. CIA) - CIA Capillary Ion Analysis (cf. CE) - COP Crystal Originated Particle detected as LPD - CV Capacitance-Voltage measurement - CVD Chemical Vapor (phase) Deposit(ion) - CZ-Si monocrystalline Si grown by Czochralski-method from quartz crucible in a noble gas atmosphere - DCT Coulbe Crystal x-ray Topography - DLTS Deep Level Transient Spectroscopy [72] - DRAM Dynamic Random Access Memories operate as memory devices by storing charge near the Si wafer surface in micro-capacitors. Defects and impurities can cause the loss of the stored charge and a periodic refresh of the signals is required (cf. PTF). - DTDA Differential Thermal Desorption Analysis [73] - DZ Denuded Zone, i.e. a subsurface layer free of SiO_x precipitates - EBIC Electron Beam Induced Conductivity - EDS Energy Dispersive Spectroscopy - EDAX Energy Dispersive Analysis of X-rays - EELS Electron Energy Loss Spectroscopy - EG Extrinsic Gettering, i.e. removal of metals from the active device region by dislocation stress in the back side of the wafer - Elymat Electrolytical Metal Tracer [69] - EMP Electron MicroProbe - EPA Electron Probe Analysis - EPMA Electron Probe Micro-Analysis - ERDA Elastic Recoil Detection Analysis - ESCA Electron Spectroscopy for Chemical Analysis (= XPS) - ETV Electro Thermal Vaporization - fab manufacturing process or fabrication line of microchips - FESEM Field Emission Scanning Electron Microscopy - FIB Focused Ion Beam - FIM Field Ion Microscopy - FLAA FlameLess Atomic Absorption - FMEA Failure Mode and Effect Analysis - ()-FTIR (Microspot) Fourier Transform InfraRed Spectroscopy - FTPL Fourier Transform PhotoLuminescence - FZ-Si monocrystalline Si grown by float zone method from a polycrystalline Si rod in an rf-coil - GDMS Glow Discharge Mass Spectrometry - GFA Gas Fusion Analysis (heat extraction of O_i from Si by graphite reduction, [75]) - GF-AAS Graphite Furnace AAS - GLP Good Laboratory Practice (protocol defining general operations) - GMP Good Measurement Practice (protocol defining technique-specific operations) - GOI Gate Oxide Integrity test - Graff test surface precipitation of metallic silicide due to quenching annealed (1100°C) Si wafer, detection by Sirtl etch, cf. TEG haze test [76, 77] - HeD He thermal Desorption spectroscopy - HIBS Heavy Ion Backscattering Spectrometry - HREELS High-Resolution Electron Energy Loss Spectroscopy - HREM High Resolution Electron Microscopy index for interstitials (O_i, Si_i etc.) in monocrystalline Si - IC Ion Chromatography - ICISS Impact-Collision Ion-Scattering Spectroscopy - ICP-OES Inductively Coupled Plasma Optical Emission Spectrometry - ICP-MS Inductively Coupled Plasma Mass Spectrometry - IG Intrinsic Gettering, removal of metallic impurities from the device active region and trap them in the bulk using supersaturated O_i in Si and inducing SiO_x precipitation by thermal annealing - INNA Instrumental Neutron Activation Analysis [70, 71] - IR InfraRed Spectroscopy - IRAS Infrared Reflection Adsorption Spectroscopy - ISS Ion-Scattering Spectroscopy (cf. RBS) - LAMMA Laser (Ablation) Microprobe Mass Analyzer - LANG scanning Lang x-ray topography - LAR-RBS Lateral and Angle Resolved RBS-Imaging [78] - LEED Low Energy Electron Diffraction - LM-PC (non-contact) Laser/Microwave PhotoConductance - LOD Limit Of Detection (2–3 of noise level, [12]) - LOQ Limit Of Quantification (>6 of noise level, Fig. 2/3, [11, 13] - LPD Ligh Point Defect, sites scattering laser beam on monocrystalline Si surface (particles, pits, dimples, scratches, nm-terrasses, etc.) - LST Laser Scattering Topography - LT-FTIR Low Temperature Fourier Transform InfraRed Spectroscopy - LTV Local Thickness Variation - LPI-SNMS Laser Resonance Ionization SNMS - MAD Mixed Acid Droplet (cf. ADD, VPD, WSSD) - MAKYOH magic mirror optical surface reflection method (Jpn.) - Mb megabit, quantum of digital unit of information, number of memory addresses of a microchip, 4 Mb is about the information capacity of 250 pages/DIN A4 - ME Monochromatic Ellipsometry - MOR Modulated Optical Reflectance - MOS MetalOxide Semiconductor (transistor) - NRA Nuclear Reaction Analysis - NRIS NonResonant Ionization Spectroscopy - OF Orientation Flat to position Si wafers due crystal orientation - OM Optical Microscopy (usually differential interference/phase contrast Nomarski microscopy) - MOS-CAP/TAU Metal Oxide Semiconductor Capacitance/generation lifetime test for minority carrier - OSF hermal Oxidation-induced Stacking Fault in monocrystalline Si [31] - -PCD Microwawe reflection Photo Conductive Decay - PAM PhotoAcoustic Microscopy - PAS Positron Annihilation Spectroscopy - PCMS Plasma Chromatography Mass Spectroscopy - PC-SIMS Polyencapsulation Secondary Ion Mass Spectroscopy - PET Puddle Etch Test (HF/HNO₃-dissolution of 10 mm spots on as-sliced, as-lapped, as-etched wafers, [43]) - PFZ Precipitation Free Zone (cf. DZ) - PIXE Particle Induced X-ray Emission - PL PhotoLuminescence - POD Power Of Detection (LOD with real sample matrices, [14]) - 4-PP 4-Point Probe - PSI Phase Shift Interferometry - PSP Protocol for Specific Purposes (defining entire measurement program) - PTF Pause Time Failure can occur between periodic refresh of the stored data (cf. DRAM) - -Raman Raman Microprobe - RBS Rutherford BackScattering (cf. ISS) - RHEED Reflection High Energy Electron Diffraction - RIS Resonant Backscattering Ion Spectroscopy - SALI Surface Analysis by Laser Ionization - SAM Scanning Auger Microprobe/Microscopy - Schimmel etch defect/preferential etching for Si(100) [79] - Secco etch defect/preferential etching for Si(100) [79] - SEM Scanning Electron Microscopy - SERS Surface-Enhanced Raman Spectroscopy - SIMS Secondary Ion Mass Spectroscopy - SIRIS Sputter Initiated Resonant Ionization Spectroscopy - SIRM Scanning InfraRed Microscopy - Sirtl etch defect/preferential etching for Si(111) [79] - SOM-DPC Scanning Opt. Micr. Differential Phase Contrast - SNMS Sputtered Neutral Mass Spectroscopy - SOP Standard Operation Procedure (defining sampling and measurement process) - SPC Statistical Process Control - SPM Scanning Photon Microscope - SPV Surface Photo-Voltage - SRP Spreading Resistance Profiling - SSD Solid State Detector or Device - STM Scanning Tunneling Microscopy - S-ULSI Super-Ultra Scale Integration (Density)=16 Mb - SXES Soft X-ray Emission Spectroscopy - TCS Total Customer Satisfaction, the hotly pursued goal of all vendors of industrial goods - TDS Thermal Desorption Spectroscopy - TDBD Time Dependent Break-Down voltage - TDDB Time Dependent Dielectric Break-down voltage - TPD Temperature-Programmed Desorption - TEG haze test according to Telefunken Electronic Ges (cf. Graff-test) - TEM Transmission Electron Microscopy - TOF-SIMS Time of Flight Secondary Ion Mass Spectroscopy - TQM Total Quality Management - TTV Total Thickness Variation - TXRF Total Reflection X-Ray Fluorescence [80] - TREX Total Reflection Energy Dispersive X-ray fluorescence - ULSI Ultra-Large Scale Integration (Density)=4 Mb - UPS Ultraviolet Photoelectron Spectroscopy - US UltraSonic - VLSI Very Large Scale Integration (Density)=1 Mb - VPD Vapor Phase Decomposition (vapor phase reaction of HF with native Si-oxide and scanning the surface with a UPW or H₂O₂ solution droplet [38, 53], cf. ADD, MAD, WSSD) - Wright etch defect/preferential etching for Si(100) and Si(111) [79] - WSA Wafer Surface Analysis - WSSD Wafer Surface Scanner Device (automated VPD) - XPS X-ray Photoelectron Spectroscopy - XRD X-ray Diffraction - XRF X-ray Fluorescence - XRT X-ray Topography - XTEM X-ray Transmission Electron Microscopy     

Accurate calibration of TXRF using microdroplet samples

TXRF has been applied in combination with VPD to the analysis of trace impurities in the native oxide layer of Si wafer surfaces down to the range of 10⁸ atoms · cm^–2. Proper quantification of VPD/TXRF data requires calibration with microdroplet standard reference wafers. The precision of calibration function has been evaluated and found to allow quantification at a high level of 3 confidence with microdroplet standard reference.     

Quantitative Assessment of Protein Adsorption by Combination of the Enzyme-Linked Immunosorbent Assay with Radioisotope-Based Studies

Protein adsorption at polymer surfaces has been investigated by means of both ELISA and radiolabeling techniques. Most of the data obtained are linearly related to each other for protein concentrations between 0.01 and 1 μg/ml, i.e., the concentration range in which the maximum amount of adsorbed active protein (ELISA) is achieved. The correlation of ELISA data with radioisotope-based measurements allows quantification of the former. Specific correlation factors are described. Adsorption is shown to be strongly dependent on the polymer/protein system.     

Littlewood’s problem for isochronous oscillators

We study the boundedness problem for a class of forced isochronous oscillators.     

Halide ion-selective electrode array calibration

The calibration of several ions (Cl(-), Br(-), F(-) and OH(-)) measured with an ion selective electrodes (ISE) array has been carried out in the presence of interferents using an experimental design and multivariate calibration methods. Partial least squares regression and principal component regression do not seem to improve the test set prediction compared to multivariate linear regression. In the case of very slight or no interference on the ISE, each ion can be determined using the corresponding ISE and univariate calibration methods, but the use of multivariate methods does not lead to worse results.     

Synthesis of Indoles Using Visible Light: Photoredox Catalysis for Palladium‐Catalyzed CH Activation

A combined palladium‐ and photoredox‐catalyzed C? H olefination enables the synthesis of indoles. By using visible light, the direct C? H activation of aromatic enamines can be achieved and a variety of indole derivatives can be obtained in good yields under mild reaction conditions.