| abstract |
PROBLEM TO BE SOLVED: To provide a technique capable of facilitating multi-leveling in a semiconductor device such as a phase change memory while minimizing variation in values after writing. SOLUTION: A memory cell including a storage element (phase change element) that stores information when a state changes with temperature and an input / output circuit are provided. When data is written, a set operation is performed (step S101). Thereafter, a write operation of desired data is performed (step S102), and the resistance value of the memory element is measured by the verify operation (step S103). If the resistance value is not within the target range, the set operation is performed again. (Steps S104 and S107), a semiconductor device having means for performing another write operation by changing the voltage applied to the memory element (Steps S105 and S108). [Selection] Figure 1 |