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Hall Effect Measurement Systems

Hall Effect Measurement System Fully integrated Lake Shore HMS are backed and supported by nearly two decades of expertise in materials characterization systems 3

4 Hall Effect Measurement System Easy Sample Access — for ease of sample exchange, the sample holder module swings forward and out of the magnet Multiple Magnet Configurations — 4-, 7-, and 10-inch electromagnetbased configurations provide fields to 2 T; fields to 9 T available in our superconducting magnet-based configuration Sample Holders — accommodate up to 6-inch wafers or up to four 1 cm2 samples LN2 Pour-Fill Bucket Dewar — included with electromagnet-based systems; cool samples to 77 K to reduce the electron scattering by lattice vibrations (phonons) Variable Temperature — measure...

Hall Effect Measurement System 5 Integrated Software — define samples and create measurement profiles from the Windows® menu-driven interface Detailed Post Processing — our optional QMSA® software package determines the mobility spectrum for each carrier species in a multi-carrier material Ergonomic Workstation — in addition to housing all of the integrated electronics, the workstation acts as a convenient tabletop AC current Hall Effect Option — extend the low-end resistance down to 10 µW for materials requiring the measurement of very low voltages Wide Resistance Range — 10 µW to 200 GW...

6 Hall Effect Measurement System Our knowledgeable technical staff is available to answer your questions Fields of Study/Research Areas A Lake Shore HMS is an ideal tool for characterizing the electronic transport properties of materials in a multitude of research areas. Strained Semiconductors Strained semiconductors with step-graded buffers have different scattering rates in each of the step buffers. The mobility and density in each layer can be determined using data from the variable field Hall measurements along with our optional QMSA software package. HTC Superconductivity and Quantum...

Hall Effect Measurement System Materials III-V Semiconductors Direct and Derived Measurements as a Function of Field and Temperature GaAs based devices: HEMTs (High Electron Mobility Transistors) pHEMTs (pseudomorphic High Electron Mobility Transistors) HBTs (Heterojunction Bipolar Transistors) FETs (Field Effect Transistors) MESFETs (Metal-Semiconductor Field Effect Transistors) Hall Voltage InP, InAs, GaN, and AlN based devices Anomalous Hall Effect (AHE) Semiconductors Hall Coefficient a-Si, Si, Ge, SiC, Si on insulator (SOI) devices, HgCdTd, ZnO SiGe based devices: HBTs and FETs Dilute...

8 Hall Effect Measurement System System Application Software The fully integrated HMS software is Windows® XP color graphic menu-driven using a Windows® Explorer® interface for system operation, data acquisition, and analysis. It controls magnetic field, temperature, and sample excitation during measurements allowing for the most comprehensive collection of measurement capabilities. The software enables the user to define and save specifications and experimental configurations, as well as record and display data in laboratory and SI units for further analysis. Real-time feedback of...

Hall Effect Measurement System U Post Processing and Analysis with QMSA® Lake Shore's Quantitative Mobility Spectrum Analysis (QMSA) software package represents that most advanced multi-carrier analysis capability available. This exclusive Lake Shore software automatically segregates the mobility spectrum for each carrier species (electrons and holes) that comprise a multilayer or multi-carrier material, including heterostructures, quantum wells, and multiply doped materials. Input for the software analysis includes Hall coefficient, resistivity, and magnetic field. Output parameters...

10 Hall Effect Measurement System Select a system to fit your applications Parameters to consider when selecting an HMS: b Resistance Range Electronic transport measurements require the calculation of resistance by measuring the voltage output and dividing by the current input. The resistance range of the sample materials to be studied determines the measurement system specifications. The Model 7700A and 9700A series HMS offer the widest possible resistance range. These systems take great care in controlling low currents and small voltages present in electron transport systems. Our AC...

Hall Effect Measurement System *Wof available with Model 7612 or 7712A 'This option is not CE-certified Our versatile HMS can measure samples from 10 mm2 (0.4 in2) up to 152 mm2 (6 in2). Our standard 7600 series can measure up to 2 samples at a time, or can be configured to measure up to 4 samples at a time. Mobility Range The wide standard mobility range of our HMS enables you to measure the widest possible range of materials. When combined with the HMS voltage tracking mode, low mobility materials typically used in organic semiconductors, molecular electronics, organic LEDs, and...

Hall Effect Measurement System Classical Measurements Step 1: Variable Temperature Measurement _ Srt«t Rwlitltfty This figure shows the resistivity of germanium vs. temperature. The sample temperature varied from 400 K to 650 K. As expected, a log plot of resistivity vs. magnetic field to 1 T is a straight line. These figures demonstrate the mobility temperature. The density is nearly mobility shows a typical electron-phonon scattering behavior. Hall effect in metals Measuring the Hall effect in metals requires some care. The resistivity of a metal is very low and the carrier density is...

Hall Effect Measurement System 13 State of the Art Measurements Transparent Oxides (ZnO) III-V Semiconductors pHEMT Mobility vs. Temp for Channel Carrier The Hall voltage of a ZnO sample was taken in voltage tracking mode. This mode is very useful for low mobility materials, as it allows Hall voltage measurements during magnetic field change. The data shows the Hall voltage and field for 10 cycles of ±10 kG field sweeps. Here, the amplitude of the Hall voltage oscillations is the true Hall signal — approximately 1.25 mV. The Hall voltage offset is almost 1 V, therefore, the true signal is...