摘要 |
There is provided a technique capable of improving speed of a set operation, which controls writing rate in a semiconductor device including a memory cell using a phase-change material. The technique uses means for setting a set-pulse voltage to be applied to the phase-change material to have two steps: the first-step voltage sets a temperature of the phase-change memory to a temperature at which the fastest nucleation is obtained; and the second pulse sets the temperature to a temperature at which the fastest crystal growth is obtained, thereby obtaining solid-phase growth of the phase-change material without melting. Moreover, the technique uses means for controlling the two-step voltage applied to the phase-change memory by a two-step voltage applied to a word line capable of reducing the drain current variation.
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