| 摘要 |
<p>PURPOSE:To improve the aged breakdown voltage of a dielectric film by setting a potential of on electrode of an information storage capacitive element of a DRAM higher than the intermediate voltage value between high and low level signal voltages fed to the other electrode and lower than a high-level signal voltage. CONSTITUTION:A fixed plate voltage Vp is applied to a plate electrode 9 functioning as one electrode of a MIS capacitive element of an information storage capacitive element C. Then the voltage Vp is set to a voltage higher than the voltage between a signal voltage Vcc and a signal voltage Vss and a voltage lower than the signal voltage Vcc, that is, the sum of 1/2Vcc and a voltage alpha. A signal voltage Vss or Vcc of a data line 18 is applied to a semiconductor region 7 functioning as the other electrode is applied through a MISFETQ. When the level of the plate electrode 9 is negative apparently, an electric field corresponding to 1/2Vcc-alpha is fed to the dielectric film 8, since the electric field applied to the dielectric film 8 is reduced, the aged breakdown voltage of the dielectric film 8 is improved.</p> |
