| 摘要 |
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 T<SB>1</SB>and guaranteed time period t<SB>1</SB>) of the ferroelectric memory device, having ferroelectric capacitance is ensured, is evaluated at an accelerated condition (guaranteed temperature T<SB>2</SB>and guaranteed time period t<SB>2</SB>). The method includes a step of determining the test time period t<SB>2</SB>required 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
|
