Nonvolatile semiconductor memory

Abstract

Abstract PURPOSE:To make a chip size small by connecting plural memory cells each comprising a MOSFET of floating gate structure in series so as to have only to provide one contact to >=2 cells thereby decreasing the number of contacts. CONSTITUTION:A memory cell comprising a MOSFET having a floating gate and a control gate consists of a circuit 10 where 4 cell elements MC1-MC4 are connected in series. Through the constitution above, the drain of the element 1 is connected to a high voltage write voltage VP via an enhancement MOSFET 11 for write voltage application and the source of the element 4 is connected to the earth at 0V. A voltage Vdata in response to a write voltage is applied to the gate of the FET11 and selection voltages VG1-VG4 are applied to the control gate of the four elements MC1-MC4 respectively. Thus, one contact is enough to the series circuit 10 to reduce the area of the contact in case of large capacity manufacture.

Inventors

• 👤 Hiroshi Iwahashi

Bibliographic Details