Hostname: page-component-78c5997874-8bhkd Total loading time: 0 Render date: 2024-11-03T08:10:13.273Z Has data issue: false hasContentIssue false

Materials Challenges in Automotive Embedded Non-Volatile Memories

Published online by Cambridge University Press:  01 February 2011

Erwin Josef Prinz*
Affiliation:
[email protected], Freescale Semiconductor Inc, Technology Solutions Organization, 6501 William Cannon Drive West, MD: OE-49, Austin, TX, 78735, United States, 512-895-8443
Get access

Abstract

Silicon-based nonvolatile memory modules are widely used in microcontrollers, where they are embedded into a monolithic system on a chip (SoC) which also includes high speed logic transistors, cache SRAM, and peripheral circuits for communicating with the external world. The physical principle most widely exploited for nonvolatile code and data storage is charge storage in floating gates. Recently, charge storage in nitride traps and nanocrystals also has been explored.

The most demanding use profiles with respect to temperatures, data retention times, and low failure rates are encountered in automotive engine control applications, where junction temperatures up to 150°C are common, for 1000's of hours. Starting with the 130nm technology node, embedded Flash technology has been integrated with copper interconnects, and at the 90nm node, low dielectric constant interlevel dielectrics are also employed to increase circuit performance. To achieve automotive reliability, the materials surrounding the silicon floating gate, nanocrystal, or nitride charge storage area must be evaluated for parasitic charge storage, write/erase stress-induced leakage current, and other parameters important for reliability. Any movement of parasitic charge, potentially over a long period of time, can reduce the sensing window of the Flash EEPROM bitcell.

Type
Research Article
Copyright
Copyright © Materials Research Society 2007

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

[1] Brown, W. and Brewer, J.. Nonvolatile Semiconductor Memory Technology. IEEE Press, New York, 1998.Google Scholar
[2] Daniels, R.. A Participant's Perspective. IEEE Micro, 46:21, December 1996.Google Scholar
[3] Kahng, D. and Sze., S. A Floating Gate and its Application to Memory Devices. Bell Syst. Tech. J., 46:1288, 1967.Google Scholar
[4] Kuhn, P. et al. A Reliability Methodology for Low Temperature Data Retention in Floating Gate Nonvolatile Memories. In 2001 International Reliability Physics Symposium, Orlando, FL., 2001.Google Scholar
[5] Muralidhar, R. et al. A 6V Embedded 90 nm Silicon Nanocrystal Nonvolatile Memory. In 2003 International Electron Devices Meeting, Washington, D.C., 2003.Google Scholar
[6] Muralidhar, R. et al. Silicon Nanocrystal Nonvolatile Memory for Embedded Flash Scaling. In International Symposium of Next Generation NVM Technology for Terabit Flash Memory SEMICON-Korea., 2006.Google Scholar
[7] Swift, C. et al. Gate Disturb Reduction in a Silicon Nanocrystal Flash EEPROM by Means of Natural Threshold Voltage Reduction. In 2006 Nonvolatile Semiconductor Memory Workshop, Monterey, CA., 2006.Google Scholar
[8] Tiwari, S.. Volatile and Non-Volatile Memories in Silicon with Nanocrystal Storage. In 1995 International Electron Devices Meeting, Washington, D.C., 1995.Google Scholar
[9] Wegener, H. et al. The Variable Threshold Transistor, a New Electrically Alterable NonDestructive Read Only Storage Device. In 1967 International Electron Devices Meeting, Washington, D.C., 1967.Google Scholar