| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a nonvolatile memory which makes it possible to prevent the deterioration of data holding characteristics before shipping for a memory cell to be natured. SOLUTION: After data holding characteristic test (step S4) in a wafer state is finished, test data is rewritten with data of reverse pattern (step S6). Then, package sealing step is executed (step S8). Thereafter, the condition of the data holding characteristic test after packaging is set (step S10). The condition is set by calculating the data pattern, heating temperature for the next memory state heating step based on the stress calculated at each data pattern for the steps S4 and S8 already conducted. The condition of the next memory state heating step is so set that the total sum of the stress at each data pattern becomes as equal as possible, and hence the 'naturing' of a ferroelectric memory can be reduced through the entire memory state heating step. |
