| 摘要 |
PURPOSE:To protect a word shunt line against disconnection caused by electromigration by a method wherein adjacent word shunt lines are formed vertically separated from each other interposing an insulating layer between them. CONSTITUTION:Word lines 8 and 8' are formed on an Si substrate 3 through the intermediary of an insulating film 13. When word shunt lines 10 and 10' adjacent to each other through the intermediary of pad electrodes 11 and 11' are formed, the shunt lines 10 and 10' are vertically separated from each other through the insulating film 22 and the electrode 12 or formed at different levels. Therefore, the shunt lines 10 and 10' are protected against disconnection due to electromigration or the stress caused by an interlaminar insulating film by making the shunt lines 10 and 10' large in width. As the coupling capacitance between the shunt lines 10 and 10' is small, an abnormal read-write operation can be prevented. Moreover, when a column address decoder selects two or more shunt lines at a time, the decoder is made to have a selection logic in which the load of the selected shunt line is always constant to any address, whereby a memory device of this design can be accelerated and stabilized in access operation. |
