Title :
A high-density dual-polysilicon 5 volt-only EEPROM cell
Author :
Lambertson, R. ; Malazgirt, A. ; Lo, C. ; Vahidimowlavi, A. ; Holland, P. ; Fliesler, M. ; Gee, H.
Author_Institution :
Xicor Inc., Milpitas, CA, USA
Abstract :
A novel full-function EEPROM cell structure is described. The cell uses two polysilicon layers, a unique sublithographic poly-poly corner contact, and compact isolation to achieve good endurance, cell current, and capacitive coupling ratios in a scaleable and relatively self-aligned technology. Both program and erase operations are done using Fowler-Nordheim tunneling between the first and second poly layers. A single 5-V supply is required for operation. The cell size is 23 mu m/sup 2/ using 0.9- mu m minimum design rules. Full array functionality has been demonstrated on a 1 Mb EEPROM. In addition, a 15- mu m/sup 2/ version of the cell, suitable for a 4 Mb EEPROM, was fabricated using 0.7- mu m minimum design rules and was shown to be functional. Test structures show endurance of better than 1 million cycles.<>
Keywords :
EPROM; MOS integrated circuits; VLSI; integrated memory circuits; 0.7 micron; 0.9 micron; 1 Mbit; 4 Mbit; 5 V; EEPROM; EEPROM cell structure; Fowler-Nordheim tunneling; ULSI; capacitive coupling; cell current; cell size; compact isolation; design rules; dual-polysilicon; endurance; erase operations; full-function; polycrystalline Si; polysilicon layers; programming operations; scaleable; self-aligned technology; single 5-V supply; single voltage supply; sublithographic poly-poly corner contact; Charge pumps; Cost function; EPROM; Isolation technology; Low voltage; Nonvolatile memory; Power supplies; Temperature distribution; Testing; Tunneling;
Conference_Titel :
Electron Devices Meeting, 1991. IEDM '91. Technical Digest., International
Conference_Location :
Washington, DC, USA
Print_ISBN :
0-7803-0243-5
DOI :
10.1109/IEDM.1991.235444
