Tài liệu Floating Gate Devices: Operation and Compact ModelingPaolo

1 INTRODUCTION
Flash Memories are one of the most innovative and
complex types of high-tech, nonvolatile memories in use
today, see for example [1]. Since their introduction in the
early 1990s, these products have experienced a continuous
evolution from the simple first ones to emulate EPROM
memories, to the extreme flexibility of design application in
today products. In the memory arena, Flash memory is the
demonstration of the pervasive use of new electronic
applications in our lives, exploiting this flexible and
powerful memory technology either as a stand-alone
component or embedded in a product. Flash are not just
memories, they are “complex systems on silicon”: they are
challenging to design, because a wide range of knowledge
in electronics is required (both digital and analog), and they
are difficult to manufacture. Physics, chemistry, and other
fields must be integrated; and conditions must be carefully
monitored and controlled in the manufacturing process.
Compact Models (CMs) of Floating Gate (FG) devices
are therefore needed and they have the same purpose of all
compact models: to be used within a program for circuit
simulation. The Floating Gate transistor is the building
block of a full array of memory cells and a memory chip. In
a first approximation, the reading operation of a FG device
can be considered a single-cell operation. Nevertheless,
CMs are fundamental to simulate the effects of the cells not
directly involved in the operation under investigation and
the effects of the parasitic elements. Furthermore,, .