Two proven designs united

The Model 8425 combines the extensive Hall measurement capabilities of our 8400 Series HMS system with the flexibility and convenience of our CRX-VF cryogen-free probe station.

The ability to probe full or partial wafers up to 51 mm (2 in) in diameter eliminates dicing of fabricated wafers, as typically required in a conventional Hall measurement system. And because the sample is under vacuum (a function not available on standard Hall systems), it’s an ideal measurement platform for materials susceptible to degradation caused by atmospheric exposure or that may require initial baking to drive out moisture.

Probing also offers the flexibility to measure more Hall structures and to use smaller devices. Repositionable probes eliminate the need for large fixed-wire contacts, and they enable multiple structures to be sampled on a wafer. Test structures can be a small as a millimeter in size.

Variable temperature and magnetic field measurements

The system provides the ability to make measurements from 10 K to 400 K, at maximum field of 2 T over the full temperature range in an automated fashion. (Manual adjustment of the probe station’s heat switch is required at several temperature points.)

Generate direct and derived Hall voltage, Hall coefficient, Hall mobility, resistance, and IV curve measurements as a function of temperature. Varying temperature enables carriers to be identified by their excitation energies and provides clues to the dominating mechanisms in materials—insights that can yield important discoveries.

Highly sensitive device probing

The platform supports up to six ultra-stable probe arms for accurate tip placement (four arms are provided as standard). It offers true 90° wafer probing and includes our patented CVT (continuously variable temperature) probes that ensure consistent contact characteristics as measurements are made over wide temperature ranges.

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

Probe undiced wafers in the Model 8425

Sample soldering is not requiredNon-destructive testing—no need to solder

The use of a probe station platform eliminates the need to attach wires to the sample (as required in a conventional Hall measurement system), speeding sample prep and avoiding any damage to the sample.

Model 8425 overview

8425 software

8425 options