Electrical conductivity by eddy current

Spreading resistance profiling is a contact-based electrical technique that measures resistivity and carrier concentration as a function of depth in silicon-substrate-based semiconductor samples. This makes it possible to accurately locate p-n junctions and verify doping profiles for individual device layers in, e.g., bipolar transistors and CMOS devices. The sample is beveled at a shallow angle (0.5–5°) to magnify the depth scale, and two tungsten carbide probes are stepped along the beveled surface under controlled pressure. The measured spreading resistance is converted to carrier concentration via calibration curves, and the results are reported as graphs of electrical resistance (Ω), resistivity (Ω∙cm), and carrier concentration (cm⁻³) versus depth (nm or µm). The displayed example price includes bevel preparation and SRP measurement of one unpatterned sample. Patterned samples can also be analyzed, and additional sample preparation (e.g., lift-off of surface layers) is available upon request. The measurement can also be combined with other services, including crystal orientation determination with XRD and chemical concentration analysis with SIMS. Please use the form below to request a quote for your analysis project.

In situ electrical characterization of semiconductor samples using electron beam induced current (EBIC) mapping. The method enables direct imaging of electrically active defects not visible in purely morphological SEM images. The sample is placed in an SEM chamber and scanned with a focused electron beam, which generates electron-hole pairs in the material. The resulting minority-carrier current is mapped pixel by pixel and overlaid on simultaneously acquired secondary electron (SE) or backscattered electron (BSE) images to locate electrically active defects, junctions, and grain boundaries with sub-micron resolution. Minority-carrier diffusion length, surface recombination velocity, and junction position can also be extracted from line-profile decay curves. The acceleration voltage of the electron beam is fully adjustable, with the most commonly used range being 0.2 kV to 20 kV. The temperature can also be selected within the range of -40 °C to 200 °C. An ohmic or Schottky contact (e.g., a thin Au, Al, or Ti/Au layer) is deposited on the sample before analysis to enable carrier collection. Cross-sectional samples can be prepared using FIB preparation. The displayed price example applies to the EBIC mapping of a bare die with a 28nm process node. Please request a quote for your specific sample.

Simultaneous mapping of the local electrical conductivity and surface topography of thin films and other semiconductor materials using conductive atomic force microscopy (C-AFM). A bias voltage is applied between the conductive probe tip and the grounded sample, and the resulting current is recorded pixel by pixel across the scan area, producing co-registered topography and current maps at lateral resolutions of 20–50 nm. At selected points, the bias can be swept to generate local current-voltage (I-V) curves. The current detection range is approximately 1 pA to 10 µA; materials with resistivity above ~10⁹ Ω·cm cannot be reliably characterized. The results are reported as co-registered topography and current maps, resistance maps where applicable, and local I-V curves for selected measurement points.

This analysis, performed according to the IEC 60243-1 or ASTM D149 standards, determines the dielectric strength of solid plastics by subjecting a flat sample plate to a gradually increasing voltage between two electrodes. The voltage at which the plastic loses its insulating properties is known as the breakdown voltage. The dielectric strength is calculated by dividing the breakdown voltage by the thickness of the sample and is typically expressed in kilovolts per millimeter (kV/mm). Samples are preconditioned at 23 °C and 50% RH for 24 hours before testing and are tested in a surrounding medium of thermostated insulating oil to prevent flashover. Typical room-temperature analysis includes five tests at 23 °C. The dielectric strength is determined from the median of the test results. Five additional tests will be conducted if any single test result deviates by more than 15% from the median. The dielectric strength is then determined from the median of the 10 results. These additional tests do not affect the price of the analysis. Maximum dielectric strength 50 kV/mm. Cryogenic and high-temperature analysis options (up to 250 °C) are also available. Please contact us for a quote tailored to your project. Note that we also offer other tests to evaluate the electrical properties of plastics, including volume & surface resistivity and comparative tracking index (CTI) determination.

Superconducting materials conduct electricity with zero electrical resistance and enable stable magnetic levitation when cooled below their critical temperature. With access to high-field installations (resistive magnets up to 37 T), we offer several measurements for confirming materials' superconductivity under extreme temperature, magnetic field, and pressure conditions, including the following: Critical current density at 4.2 K in fields up to 15 T, Magnetization from 2–300 K in fields up to 9 T, Critical temperature (Tc) by transport or magnetization, Thermal expansion from 4.2–300 K, Thermal conductivity and specific heat capacity from 2–300 K, Critical current vs. strain at 77 K, Tensile testing at 4.2 or 77 K with forces up to 500 kN, Fatigue testing at 4.2 or 77 K, Fracture toughness at 4.2 or 77 K. These measurements support the functional characterization of materials such as high-temperature superconductor (HTS) wires, tapes, and coils, superconducting thin films, low-temperature superconducting cables and conductors, and components for superconducting magnets. Please contact us for more information and a quote.

Hall effect measurement enables the determination of key semiconductor parameters such as carrier mobility, carrier concentration, and Hall coefficient. In this measurement, a current is applied through the sample in combination with a perpendicular magnetic field. The resulting potential (Hall voltage) is measured, and by knowing the sample thickness and resistivity, typically measured by the van der Pauw method, the charge-carrier concentration and carrier mobility can be calculated. Measurements are typically performed from room temperature to 200 °C in air, but temperatures from -150 °C to 600 °C are available upon request. Typical measurement ranges: Charge carrier concentration: ~107–1021cm-3, Resistivity: ~10-4–107Ωcm, Mobility: ~0.1–107 cm2/Vs.

Electrochemical capacitance voltage (ECV) profiling is a destructive characterization technique used to measure doping profiles in semiconductor heterostructures. By bringing a liquid electrolyte into contact with the semiconductor sample, a junction analogous to a Schottky barrier is formed. This junction creates a depletion region, i.e., a region depleted of holes and electrons but with ionized charges and electrically active defects or traps. The depletion region acts as a dielectric exhibiting voltage-dependent capacitance. By performing capacitance-voltage measurements, carrier concentration can be calculated. Depth profiling is achieved by electrolytically etching the semiconductor. A typical measurement covers a 2 µm depth profile. Other depths in the range of 0.05 µm to 50 µm can be analyzed on request.

Four-point probe measurement is a method used to measure the resistivity and conductivity of conductive and semiconductive materials, including thin films. As the method uses separate current and voltage probes, the impact of contact resistance is minimized compared to a traditional two-point probe measurement. In a standard four-probe measurement setup, the probes are equally spaced from one another. By applying a known current through the two outer probes and measuring the voltages at the inner probes, sheet resistance can be determined by using Ohm's law. When samples have an arbitrary shape, it is common to use the van der Pauw method. In this case, the four probes are placed around the perimeter of the sample. Measurements can be performed from room temperature to 200 °C in air.

X-Ray Reflectometry (XRR) analysis is used to measure the density (g/cm3), thickness (nm), and roughness (nm) of thin films. The method is applicable to the characterization of single- or multilayered thin films, as it provides information on the thickness and density of individual layers of the sample material as well as the roughness of the interphases. Greatest accuracy for XRR thickness measurements is generally achieved for samples containing 1-200 nm thick surface layers with under 5 nm RMS roughness. Thicker films and coatings with rougher surfaces can also be characterized, but the accuracy of thickness determination decreases as the thickness and roughness of the film or film stack increase. >150 mm wafers are typically cut to fit the sample holder. Please let us know if you need testing for larger wafers that cannot be cut into pieces. The available temperature range for XRR measurements is 25-1100 °C, and crystallinity can be studied as a function of temperature. The measurements can be performed under a normal atmosphere, inert gas, or vacuum. Measurements are typically performed using one of the following instruments: Rigaku SmartLab, Panalytical X'Pert Pro MRD, Bruker D8 Discover. Please let us know if you have a preference for a specific instrument.

During this analysis, the surface of a smooth and hard sample is imaged with an atomic force microscope (AFM). Topological images are typically provided from three locations around the sample. The measurement area is 5 x 5 micrometers, if not otherwise agreed. Measurements are typically done using the following instrument: Bruker Dimension Icon.