Mobility measurements with a standard contact resistance pattern

The standard test pattern used for planar-contact resistance measurements yields values for normalized contact resistance, contact resistivity, and semiconductor sheet resistance. Application of a perpendicular magnetic field yields additional data, including bulk semiconductor mobility and sheet carrier concentration, and also the mobility of the material under the contact. This new technique is applied to a GaAs implanted layer designed for metal-semiconductor field-effect transistor (MESFET) applications. One advantage of the method is that a separate Hall-effect measurement is no longer necessary.