| 摘要 |
PROBLEM TO BE SOLVED: To quantitatively and rapidly estimate the life of a semiconductor device corresponding to the kind and characteristics of a member by estimating the change of first electrical stress with the elapse of time when a predetermined second electrical stress is applied and cumulating the consumption ratios of life at respective time intervals in the change characteristics with the elapse of time. SOLUTION: The time change to the elapse of the time (t) of gate voltage to respective current values J1, J2 being the first electrical stresses to a gate oxide film and destruction charge quantities QBD 1, QBD 2... injected up to destruction are calculated. Next, the dependence QBD(J) to the constant current density J of QBD at a time of destruction and the change j(t) to the stress time (t) of current density (i) under constant voltage is estimated by procedure using a predetermined formula. Next, effective life consumption ratios at respective minute time intervalsΔt are cumulated and calculated on the basis of the predetermined formula and life tBD is calculated until the sum of them becomes '1'. Next, the life tBD is multiplied by a proper safe coefficient 1/S to estimate the reliability and life of the gate oxide film.
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