| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor memory device having a low operating voltage and capable of retaining recorded data for a long period. <P>SOLUTION: A selection transistor 20 composed of an N-type metal-insulator semiconductor field effect transistor (MISFET) includes: N-type source/drain regions 4 and 5 provided spaced apart from each other in an upper potion of a semiconductor substrate 1; a channel region formed between the N-type source/drain regions 4 and 5 in the upper portion of the semiconductor substrate 1; and a gate electrode 3 formed on the channel region via a gate insulating film 2. A resistance change element 30 includes a lower electrode 30a, an upper electrode 30c, and a variable resistance layer 30b that is sandwiched between them and whose resistance value reversibly changes based on electrical signals having different polarities. The second threshold voltage defined between the gate electrode and N-type source/drain region 5 is larger than the first threshold voltage defined between the gate electrode and the N-type source/drain region 4 in the MISFET. <P>COPYRIGHT: (C)2012,JPO&INPIT |
