VLSI-Design of Non-Volatile Memories

The electronics and informaTIon technology revoluTIon conTInues, but it is a criTIcal

time in the development of technology. Once again, we stand on the brink of a

new era where emerging research will yield exciting applications and products

destined to transform and enrich our daily lives! The potential is staggering and

the ultimate impact is unimaginable, considering the continuing marriage of technology

with fields such as medicine, communications and entertainment, to name

only a few.

But who will actually be responsible for transforming these potential new products

into reality? The answer, of course, is today’s (and tomorrow’s) design engineers!

The design of integrated circuits today remains an essential discipline in support

of technological progress, and the authors of this book have taken a giant step

forward in the development of a practice-oriented treatise for design engineers

who are interested in the practical, industry-driven world of integrated circuit design.

The authors, Giovanni Campardo and Rino Micheloni, are very well qualified

to effectively address this challenging objective. Both have a solid track record of

leading design activities at the STMicroelectronics Flash Division. I should

probably mention at this point my association with and knowledge of the accomplishments

of these authors. In April 2003, they published a unique Special Issue

on the subject of Flash Memories for the Proceedings of the IEEE, the journal for

which I am Managing Editor. Therefore, I have firsthand knowledge of their approach

to the development of very well crafted technical material.

In addition, a third member of the author team, David Novosel, has provided

invaluable assistance, particularly in the translation efforts on this material. David

is President and founder of Intelligent Micro Design, Inc. which specializes in the

design of custom memories and analog circuits, which is located in Pittsburgh,

PA.

This book is intended for Electrical Engineering graduates who want to enter

into the integrated circuit design world. Nonvolatile memories, in many cases, are

treated as an example to explain general design concepts (basic circuits, layout,

design flow, etc.). Practical illustrative examples of nonvolatile memories, including

flash types, are showcased to give insightful examples of the design approaches

that are discussed. The authors introduce the key nonvolatile memories

design issues in the first section and they discuss the various functions and capabilities

of these memories; much of these discussions are based on their recently

published Special Issue on the subject of Flash memories.After a complete review of the general design issues, the authors begin to focus

on the important concepts that should be understood. For example, they introduce

MOS Process and briefly review the CMOS building blocks and the four available

components. In the next section the authors describe Memory cell operations including

Read and Erase operations, as well as coverage of software and program

issues.

Comprehensive sections on Design Building Blocks, Integrated circuits layout,

and Matrix architecture are included. They explore in some depth Input buffers,

Output Buffers Decoders and Program and Erase operations circuitry. They discuss

the subjects of Timers and Read operation sensing techniques.

Two sections deal with quality and dependability-related issues, and cover the

subjects of Redundancy and Test Modes. Coverage is also provided on ESD &

latch-up issues as well as Embedded Flash algorithms.

A collection of photos is included to make the reader familiar with silicon aspects.

Throughout all parts of this book, the authors have taken a practical and applications-

driven point of view, providing a comprehensive and easily understood

approach to all the concepts discussed.

I greatly appreciate the very kind invitation of the authors to submit these

words of introduction for their exciting new book. I wish them continued success

in their latest publishing enterprise, but more importantly I hope that all who are

reading these words will derive knowledge and understanding from the sincere

and dedicated efforts of the authors.