Tri Gate Transistor | Electrical Seminar Topic
Tri Gate Transistor
Tri-Gate transistors, the first to be truly
three-dimensional, mark a major revolution in the Semiconductor industry. The
semiconductor industry continues to push technological innovation to keep pace
with Moore’s Law, shrinking transistors so that ever more can be packed on a
chip. However, at future technology nodes, the ability to shrink transistors
becomes more and more problematic,
in part due to worsening short channel effects and an
increase in parasitic leakages with scaling of the gate-length dimension. In
this regard Tri-gate transistor architecture makes it possible to continue
Moore's law at 22nm and below without a major transistor redesign. The physics,
technology and the advantages of the device is briefly discussed in this paper.
Since their inception in the late 1950s, planar transistors
have acted as the basic building block of microprocessors. The scaling of
planar transistors requires the scaling of gate oxides and source/drain
junctions. However, as these transistor elements become harder to scale, so
does the transistor gate length.
The scaling of planar transistors is getting more difficult
due to the worsening electrostatics and short-channel performance with reducing
gate-length dimension. In a multigate device, the channel is surrounded by
several gates on multiple surfaces, allowing more effective suppression of
"off-state" leakage current. Multiple gates also allow enhanced
current in the "on" state, also known as drive current.
These advantages translate to lower power consumption and
enhanced device performance. Non-planar devices are also more compact than
conventional planar transistors, enabling higher transistor density which
translates to smaller overall microelectronics
state, also known as drive current. These advantages
translate to lower power consumption and enhanced device performance.
Non-planar devices are also more compact than conventional planar transistors,
enabling higher transistor density which translates to smaller overall microelectronics
A new transistor architecture that can significantly improve
the electrostatics and short-channel performance is the tri-gate transistor, as
shown in Figure 1.
This transistor, which can be fabricated either on the SOI
substrate or standard bulk-silicon substrate, has a gate electrode on the top
and two gate electrodes on the sides of the silicon body. The top-gate
transistor has physical gate length LG and physical gate width WSi, while the
side-gate transistor has physical gate length LG and physical gate width HSi,
