| 摘要 |
PURPOSE:To rapidly and accurately evaluate the insulation breakdown characteristic of an insulative film having time dependence in a non-destructive state, by measuring a charging current by the application of pulse voltage and judging the quality of the insulating film on the basis of a transition current wave form. CONSTITUTION:A single-emitted pulse having a predetermined width is applied to the gate insulating film 3 of the substrate 2 of a specimen 1 so as to make an electrode 4 negative by a pulse voltage generation apparatus 5. At this time, an inrush current limited by a resistor 6 is flowed to the film 3 and, thereafter, a charging current being a transistion current is flowed and the current wave form thereof is measured by a wave form measuring apparatus 7. When the film 3 is normal, the wave form of the charging current continuously reduces and there is no wave form strain and a current at a steady time becomes also small. Therefore, by judging whether the measured current wave form by the apparatus 7 is received in a prescribed limit wave form, the insulating breakdown characteristic of the insulating film having time dependence can be rapidly and accurately evaluated in a non-destructive state without performing the measurement of the change in a capacity-voltage characteristic by the magnitude of pressure-tightness at the time of destruction, the calculation of surface charge density requiring a time or a temp. |
