Semiconductor memory device and driving method thereof

Abstract

First active regions and second active regions intersecting the first active regions at a right angle are defined on the surface of a semiconductor substrate, and diffusion regions are formed in the first and second active regions to interpose an intersecting region therebetween. Then, a gate structure is formed linearly to extend over the intersecting region at a non-zero angle with respect to the first and second active regions. Further, terminals to be connected to metal interconnects are provided on the diffusion regions at a non-zero angle with respect to the first and second active regions, respectively. Consequently provided is a nonvolatile semiconductor memory having a simple gate structure capable of storing 4-bits of information in one memory cell.