Molecular beam epitaxial growth of III-V semiconductor ... - KOBRA

2.2 Nanotechnology Approach to QDs Fabrication Methods
electronic circuits could bring huge prospect for the existing advanced semiconductor
technology [3, 16, 17].
2.2 Nanotechnology Approach to QDs Fabrication
Methods
The increasing demands on modern technology and energy conservation in the
last decade as well as the future plans of semiconductor industry made the semiconductor
companies to think more about reducing the costs and the dimensions
of their devices and products. However, at the same time keeping or increasing
the eciency of their products is another critical concern, by taking into account
the new material selection and design which have the lower energy consumption
due to the fact that the energy resources are limited. Nanotechnology is one of
the keys to the development of novel materials, devices and systems.
Precise
control of nanomaterials, nanostructures, nanodevices and their performances is
essential for future innovations in technology and energy consumption.
Nanotechnology is an advanced technology that has received a lot of attention
for its ability to make use of the unique properties of nanosized materials.
Nanotechnology is capable of manipulating and controlling material structures at
the nano level and oering unprecedented functions and excellent electrical, optical
and magnetic material properties. Nanotechnology consists of the "top-down
approach" and the "bottom-up approach".
The top-down approach is based
on fabrication of nanostructures by nano-lithography (e.g., electron, ion beam
or nanoimprint patterning) and etching techniques (e.g., wet- or dry-chemical
etching), such as in semiconductor manufacturing can lead to the processing of
nanosized ne structures. In the bottom-up approach, self-organization properties
inherent in materials can be utilized to assemble ne nanostructures from the
atomic or molecular levels (e.g., self-assembled quantum dots growth by MBE,
formation of nano-crystallites with special plasma deposition processes). Moreover,
there is another mixed approach of nanofabrication which consist of the
combination of the last two approaches top-down and bottom-up (e.g., quantum
dot growth on pre-patterned substrates). Controlling materials at the nano
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