| 摘要 |
PROBLEM TO BE SOLVED: To provide a method by which the dielectric break service life of the insulating film of a semiconductor element can be predicted with high reliability without requiring complicated calculations by easily and appropriately setting discriminating currents, which are used at the time of measuring the dielectric break voltage of the insulating film for a method for evaluating the insulation of film for semiconductor element. SOLUTION: At measuring a dielectric breakdown voltage VBD of the insulating film of a semiconductor element, the voltage VDB is found by changing the breakdown discriminating currents in several stages, for example, to 0.01 A/cm2, 0.1 A/cm2, and 1 A/cm2 and the effective film thickness Xeff of the insulating film at each discriminating current is calculated. By performing this process on each of a plurality of samples, a value Xeff(max) of the most frequent effective film thickness Xeff at each discriminating current is found, and a graph is prepared with the discriminating currents as an x-coordinate axis and the value Xeff(max) as a y- coordinate axis. In addition, a dielectric breakdown life tBD of the insulating film is predicted by finding the discriminating current at which an actual oxide film thicknesses XOX of the samples obtained by capacitance measurement coincides with the effective film thickness Xeff(max) from the graph and the dielectric breakdown voltages VBD by using the found discriminating current as the discriminating current of the samples.
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