| 摘要 |
PURPOSE:To measure the trap level of a small number of carriers of the MOS type diode easily and efficiently by extracting a change of a depletion layer based on the thermal discharge of a small number of carriers after stopping the application of light pulse-waves as a transient change of high-frequency capacitance. CONSTITUTION:Light pulse-waves having energy of the width or more of a forbidden band are emitted from a light pulse generator 3 under the state in which the temperature of the MOS type diode 6 is varied by controlling a heater 9, and irradiated to the gate electrode side of the MOS type diode 6 through a semipermeable reflector plate 4. The irradiation of light pulse-waves is stopped, and the change of the depletion layer based on the thermal discharge of a small number of carriers in the MOS tupe diode 6 is measured by a high-frequency capacity meter 13 as the transient change of high-frequency capacitance. A high-frequency capacitance transient change signal transmitted from the high-frequency capacity meter 13 is multiplied by a weighting signal consisting of two pairs of rectangular waves and its differential signal is extracted in a signal control-processing device 7. |
