Lake Shore 8425 HMS and Probe Station

Lake Shore 8425 HMS and Probe Station enables users to perform non- destructive Hall measurement of wafer-scale materials in a controlled cryogenic environment.

It can also be used for measuring electronic and magneto- transport properties of materials like III-V semiconductors, II-VI semiconductors, elemental semiconductors and high-temperature superconductors.

The Model 8425 combines the flexibility and convenience of Lake Shore’s CRX-VF cryogen-free probe station with 8400 Series HMS system. The system can probe full or partial wafers with diameters up to 51mm, thereby eliminating the need to dice fabricated wafers as in traditional Hall measurement system. The presence of repositionable probes enables sampling of multiple structures on a wafer.

The system enables measurements from 10K to 400K, at maximum field of 2T over the full temperature range in an automated manner. Varying temperature of the system facilitates identification of carriers of materials by their excitation energies, thereby providing a better understanding of major mechanisms.

The platform can accommodate up to six ultra-stable probe arms for precise tip placement. The patented CVT probes ensure consistent contact characteristics over a wide range of measurements.

The Model 8425 includes a compact vacuum turbopump, a closed-cycle refrigerator (CCR) for cryogen-free operation, and a vertical field superconducting magnet.

Model 8425 Software

The fully integrated HMS software consists of a Windows^® graphic menu-driven interface that can be used for system operation, data acquisition, and analysis. By delivering the collection of measurement capabilities, the software can also be used to control magnetic field, sample temperature, and sample excitation. It also ensures a complete control over measurement parameters in real time.

The processed display can be shown in tabular or graphical form. Using the SQL reporting capabilities, the software can directly print the data and plots to a Microsoft Excel^® spreadsheet, Microsoft Word^®, or PDF documents.

The 8400 Series supports Hall bar and van der Pauw measurement geometries to measure sample sheet resistivity. The Hall bar method employs one dimensional current flow approximation and allows measurement of samples with gated Hall bars.

After setting up the measurement, the software continuously monitors the sample temperature. The measurements are executed within the temperature loop when the temperature reaches the next trigger temperature. The sample temperature, however, changes continuously while carrying out the measurements.

The 8400 Series also supports Quantitative Mobility Spectrum Analysis (QMSA) software package to carry out advanced multi-carrier analysis.

Lake Shore 8425 HMS and Probe Station

Non-destructive testing — no need to solderTwo proven designs unitedModel 336 temperature controllerA comparison between standard probes and CVT probes.Cernox™ temperature sensorHall measurement setupDefine a sampleSoftware toolbox with resistance utilityExample of a DC measurement results screenExample of an ohmic checkExtra probe arms for Hall bar measurementsPS-HV-CPX high-vacuum kit option

Additional Features

The Model 8425 system can be shipped with four probe arms for van der Pauw measurements and the 84-HBM option with probe arm cabling, mounts and two extra probe arms for Hall bar measurements.

The PS-HV-CPX high- vacuum kit option is suitable for applications that require lower base pressures than that in the vacuum system included in the basic Model 8425 probe station.

The vision system of the probe station contains highly sensitive 7:1 zoom optics and color CCD camera chosen for low light sensitivity, thereby ensuring high image quality.

With 84032P gate bias option, the gate bias voltage can be set according to the user-determined value which improves the Hall measurement flexibility. Furthermore, the 84031 option enables a resistance measurement in the range of 10kΩ up to 100GΩ.

Key Features

The main features of the 8425 HMS with Probe Station include:

DC fields to 2T and resistances from 0.5mΩ to 100GΩ

Supports a wide range of DC field Hall measurements

Complete Hall effect measurement system with device probing under vacuum in a probe station

Varies temperatures from 10K to 400K using closed-cycle refrigerator

No cryogen required

Includes intuitive 8400 Series software

Applications

The main applications of the 8425 HMS with Probe Station include:

Hall voltage measurement

IV curve measurements

Carrier type/concentration/density

Hall coefficient and Hall mobility measurement

Magnetoresistance

Magnetotransport

Anomalous Hall effect (AHE)