RELIABILITY EXAMINATION METHOD OF FERROELECTRIC MEMORY DEVICE

PROBLEM TO BE SOLVED: To surely determine a test time period in a thermal accelerating test for evaluating the retention characteristics of a ferroelectric memory device for carrying out a reliability test for evaluating a retention characteristic lifetime. SOLUTION: In a reliability test method of a ferroelectric memory device, whether the lifetime due to a retention characteristic under a practical using condition (guaranteed temperature T1and guaranteed time period t1) of the ferroelectric memory device, having ferroelectric capacitance is ensured, is evaluated at an accelerated condition (guaranteed temperature T2and guaranteed time period t2). The method includes a step of determining the test time period t2required for evaluating whether the life due to the retention characteristic is ensured, based on the thermal dependance of the temporal changes of the bit-line voltage that occurrs when data written into the ferroelectric memory device is read out. COPYRIGHT: (C)2006,JPO&NCIPI