| 摘要 |
<p>PURPOSE: To improve the reliability of a measured value even under such a condition that the Hall voltage becomes smaller than a non-balanced voltage by altering the combination of directions, etc., of a current for every stage of increasing the magnetic flux density of an applied magnetic field. CONSTITUTION: An electromagnet 4 gives a magnetic field perpendicularly to the surface of a semiconductor sample 10 according to a current from a power source 3, and a constant-current source 5 supplies a current to the four electrodes of the sample 10 via a scanner 6. The magnetic flux density of the applied field is stepwise increased, the combination of the direction of the current, the direction of the field and the voltage measuring electrode is altered for every increasing stage, and the voltage is measured by a voltmeter 7. By conducting the summing mean of the measured voltages, a first mean value is obtained. And also, by conducting the summing mean of the values obtained by subtracting the first mean value from the measured value, a second mean value is obtained. When the magnetic flux density is proportional to the second value, the second value is decided as the Hall voltage, and when it is not proportional, the first value is decided as the Hall voltage.</p> |
