| US 7,592,659 B2 | ||
| Field effect transistor and an operation method of the field effect transistor | ||
| Kazunori Isogai, Kyoto-fu (Japan) | ||
| Assigned to Panasonic Corporation, Osaka (Japan) | ||
| Filed on Mar. 03, 2006, as Appl. No. 11/366,822. | ||
| Claims priority of application No. 2005-058797 (JP), filed on Mar. 03, 2005. | ||
| Prior Publication US 2006/0223251 A1, Oct. 05, 2006 | ||
| Int. Cl. H01L 27/108 (2006.01) | ||
| U.S. Cl. 257—300 [257/295; 257/296; 257/E29.344; 257/E29.345] | 12 Claims |
| 1. A field effect transistor comprising:
a semiconductor substrate;
a gate electrode; and
a gate insulator film provided between the semiconductor substrate and the gate electrode, wherein
the gate insulator film itself has a variable capacitance exhibiting one of a plurality of values depending on a level of
an applied voltage,
the field effect transistor has a plurality of threshold voltages corresponding to the plurality of values of the variable
capacitance of the gate insulator film, and
the plurality of threshold voltages correspond to data to be stored.
|