Device for Semiconductor Carrier Mobility Measurement

Abstract

A novel method and a device measuring the mobility of majority carriers in semiconductors using the Hall current is proposed and experimentally tested. The geometry of the mobility-determining structures is similar to the topology of the so-called Corbino disk. The semiconductor wafer, in our case, n-silicon, has circular form and two concentric ohmic contacts: one of them in the central zone of the disk, and the other around the circumference. In contrast to this well-known Corbino configuration, the peripheral electrode is interrupted, whereas the size of the so-formed arc is many times smaller than the remaining section of the external perimeter. The two ohmic contacts are brought together to a current source, and the external magnetic field is applied perpendicularly to the disk plane. The ends of the interrupted electrode are connected to an electronic galvanometer measuring the Hall current involved in the Corbino structure. The experiments were carried out at room temperature and in liquid nitrogen. The results obtained with the new device are comparable to the previously known mobility values.