| 摘要 |
PURPOSE:To enable measurement of allowable surge level in a short time, by applying pulses of different current values to each of a plurality of sample groups each comprising the same number of objects to be inspected to determine the distribution of repetition frequency until they are broken. CONSTITUTION:Three groups of samples are extracted at random from one lot having 1,000-3,000 pieces of semiconductor elements by picking up 20 pieces each. First, a pulse of 2A is applied repeatedly to 20 samples in the first group and the repetition frequency is counted until they are broken. Then, likewise, pulses of 1.8A, 1.6A respectively are applied repeatedly to 20 samples in the second and third groups and the repetition frequency is counted until they are broken. Thereafter, the relation between the current value and the repetition frequency in the area yet to be measured is estimated from the relationship between the center value of the distribution of repetition frequency and the repetition frequency itself. For example, 0.9A can be read out for the current value at which the samples are broken by 1,000 times of repetition.
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