| 摘要 |
PURPOSE:To enable the direct reading of the Hall voltage of a sample by a method wherein side surfaces opposed to each other of a semiconductor sample are provided with two pairs of electrodes at fixed intervals in the direction of current flow, and the middle point output of one pair is adjusted so as to reduce to zero the output of a differential amplifier resulting from the amplification of the output of the impedance conversion of the middle point output of the electrodes of each pair. CONSTITUTION:When a voltage of approx. 10V is impressed on the semiconductor sample 1 from a power source 12, microcurrent flows to the sample 1, but this microcurrent does not uniformly flow through the sample 1. Therefore, one pair of electrodes 16 and 16a become different from the other pair of electrodes 17 and 17a in potential. The potentials thereof are detected by voltage detection means 30 and 31, and the middle point outputs are inputted to a differential amplifier 28 through impedance converters 27 and 29. The input to this amplifier 28 has the other middle-point output with one middle-point output as the reference adjusted by a potentiometer 26 so that the output of the amplifier may become zero. Next, a magnetic field is impressed in a direction rectangular to the current I flowing through the sample 1, and a voltage VH generating at the output end of the amplifier 28 is measured according to the voltage generating in the sample 1 by Hall effect. |
