Title :
A 0.54 μm2 self-aligned, HSG floating gate cell (SAHF cell) for 256 Mbit flash memories
Author :
Shirai, H. ; Kubota, T. ; Honma, I. ; Watanabe, H. ; Ono, H. ; Okazawa, T.
Author_Institution :
ULSI Device Dev. Lab., NEC Corp., Sagamihara, Japan
Abstract :
A 0.54 μm2 self-aligned memory cell with hemispherical-grained (HSG) poly-Si floating gate (SAHF cell) has been developed for 256 Mbit flash memories. Applying hemispherical-grained (HSG) poly-Si to floating gate extends the upper surface area to double that of the floating gate in comparison with the conventional ones. A high capacitive-coupling ratio of 0.8 and buried n+ diffusion layers which are self-aligned to the floating gate poly-Si are realized simultaneously with a simple cell structure and fewer process steps
Keywords :
EPROM; MOS memory circuits; cellular arrays; diffusion barriers; elemental semiconductors; integrated memory circuits; memory architecture; silicon; 256 Mbit; SAHF cell; Si; capacitive-coupling ratio; diffusion layers; flash memories; hemispherical-grained polysilicon; self-aligned HSG floating gate cell; upper surface area; Application software; Fabrication; Flash memory; Handheld computers; Laboratories; Mobile computing; National electric code; Nonvolatile memory; Operating systems; Ultra large scale integration;
Conference_Titel :
Electron Devices Meeting, 1995. IEDM '95., International
Conference_Location :
Washington, DC
Print_ISBN :
0-7803-2700-4
DOI :
10.1109/IEDM.1995.499304
