Nonvolatile semiconductor storage device and manufacture thereof

Abstract

Abstract PURPOSE:To enlarge the coupling capacity between a floating gate and a control gate so as to realize high integration by providing a trench at the side face of the floating gate, and forming a second gate insulating film at the inner face of the trench as well as the side face, and arranging a control gate in opposition to the topside, the side face, and the trench inner face of the floating gate. CONSTITUTION:A floating gate 5 is processed in fin shape, with a trench 10 cut at the whole periphery of the side face. A second gate insulating film 6 is formed all over the topside and the side face of the floating gate 5 and the inner face of the trench 10. A control gate 7 is so formed as to not only oppose the topside of this floating gate 5 but also oppose the side face and the inner face of the trench 10 formed here. N<+>-type diffusion layers 8 and 9 to become a drain and a source are formed in a substrate with these gate regions in between. The floating gates 5 are independent with every memory cell, and the control gates 7 are arranged continuously in common to memory cells usually in one direction thereby constituting a word line.

Inventors

• 👤 Tetsuo Endo
• 👤 哲郎 遠藤
• 👤 Satoshi Inoue
• 👤 聡 井上

Bibliographic Details