Excavating
Patent
1996-09-27
1997-08-26
Canney, Vincent P.
Excavating
365201, G11C 700
Patent
active
056617305
ABSTRACT:
A test method for ferroelectric memories includes the steps of: functionally testing the ferroelectric memories to determine functional yield; storing the ferroelectric memories for at least eight hours; writing an initial pattern into the ferroelectric memories; baking the ferroelectric memories; reading the initial pattern to determine same state yield; writing an inverse pattern into the ferroelectric memories; reading the inverse pattern to determine opposite state yield; and again writing the initial pattern into the ferroelectric memories. The steps of baking, reading the initial pattern and writing the inverse pattern, and reading the inverse pattern and writing the initial pattern are repeated for a number of test cycles. The ferroelectric memories are baked at a temperature of about 150.degree. C. for a predetermined duration that is incremented with each successive test cycle.
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Hackbarth Holden
Mitra Sanjay
Canney Vincent P.
Meza Peter J.
Ramtron International Corporation
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