| 摘要 |
PURPOSE:To obtain a memory device having high reliability and the high degree of integration by selectively breaking an SiO2 film on the surface of poly Si buried in a window in an SiO2 film on an Si substrate, connecting poly Si to a wiring on the SiO2 film and forming a cell substituted for a redundancy memory between a decoder and a decoder. CONSTITUTION:A memory cell row 11 is formed in a substrate 21, a window 23 is bored to an SiO2 film 22 on an impurity layer 25 in the surface of the substrate, and a poly Si layer 24 is shaped. An SiO2 film 26 is formed on the surface, and a conductor 27 is wired. Voltage is applied between the substrate 21 and the conductor 27 to selectively break the SiO2 film 26, and one bit is memorized. Driving wires for all lines and rows are formed among the cell 20, a gate in a driver 31 and a decoder 32. Only the cell 20 for the driver 31 connected to driving wires crossing with a defective memory cell is broken and conducted. When the defective memory cell is brought to an access state, the decoder 32 is turned OFF, the corresponding driver 31 cannot be turned ON because the cell 20 is conducted, and the defective memory cell is not turned ON. According to the constitution, substitution for a redundancy memory cell is executed with high reliability, and a memory device having the high degree of integration is obtained. |
