
The front-end-of-line (FEOL) is the first portion of
IC fabrication where the individual components (
transistor
upright=1.4, gate (G), body (B), source (S) and drain (D) terminals. The gate is separated from the body by an insulating layer (pink).
A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch ...
s,
capacitor
A capacitor is a device that stores electrical energy in an electric field by virtue of accumulating electric charges on two close surfaces insulated from each other. It is a passive electronic component with two terminals.
The effect of a ...
s,
resistor
A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias activ ...
s, etc.) are patterned in the
semiconductor
A semiconductor is a material which has an electrical conductivity value falling between that of a conductor, such as copper, and an insulator, such as glass. Its resistivity falls as its temperature rises; metals behave in the opposite way. ...
.
FEOL generally covers everything up to (but not including) the deposition of metal
interconnect layers.
For the
CMOS process, FEOL contains all fabrication steps needed to form isolated CMOS elements:
# Selecting the type of
wafer to be used;
Chemical-mechanical planarization and cleaning of the wafer.
#
Shallow trench isolation (STI) (or
LOCOS in early processes, with
feature size
Feature may refer to:
Computing
* Feature (CAD), could be a hole, pocket, or notch
* Feature (computer vision), could be an edge, corner or blob
* Feature (software design) is an intentional distinguishing characteristic of a software item ...
> 0.25 μm)
#
Well formation
A well is an excavation or structure created in the ground by digging, driving, or drilling to access liquid resources, usually water. The oldest and most common kind of well is a water well, to access groundwater in underground aquifers. The ...
#
Gate
A gate or gateway is a point of entry to or from a space enclosed by walls. The word derived from old Norse "gat" meaning road or path; But other terms include '' yett and port''. The concept originally referred to the gap or hole in the wal ...
module formation
#
Source and drain module formation
See also
*
Back end of line
The back end of line (BEOL) is the second portion of IC fabrication where the individual devices (transistors, capacitors, resistors, etc.) get interconnected with wiring on the wafer, the metalization layer. Common metals are copper and alumi ...
*
Integrated circuit
References
Further reading
*"CMOS: Circuit Design, Layout, and Simulation" Wiley-IEEE, 2010.
pages 177-178(Chapter 7.2 CMOS Process Integration); pages 180-199 (7.2.1 Frontend-of-the-line integration)
Electronics manufacturing
Semiconductor device fabrication
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