Chemistry Reference
In-Depth Information
randomness of events at different temporal and spatial scales, that is, the duality of the
stochastic nature of the microscopic and atomic events and the deterministic macro-
scopic phenomena. Such duality, as a general materials property, exhibits in all the phe-
nomena on silicon electrodes. For examples, random removal of individual silicon
atoms from the surface versus the predictable etching rate of the surface, the random
locations of initiation of pores versus the deterministic direction of propagation of
pores, the randomness of surface lattice structure at the atomic and near atomic scales
versus the deterministic surface roughness at a macroscopic scale.
9.7. FUTURE RESEARCH INTERESTS
The amount of information on the electrochemical properties of silicon, as
summarized in this topic, is enormous owing to the research interests over the last
five decades. The intensity of research on silicon electrodes is likely to continue in the
foreseeable future for three major reasons.
The primary reason is the continued use of silicon as the mainstream material for
future generations of electronic devices.
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Many problems encountered in
the diminishing device feature size are related to surface properties of silicon, such as
surface roughness, which are determined by the numerous wet processes, such as clean-
ing. In addition, the increasing applications for sensors and actuators that are com-
patible with integrated circuits demands the fabrication of micro mechanical devices
that are three-dimensional and moveable. Chemical etching of silicon with its large
range of etch rates and selectivity with respect to orientation, doping type and con-
centration, and foreign materials, is one of the key processes for the fabrication of theses
517,851,918
Also, there is a renewed interest in electrodeposition of metals such as
copper for replacing aluminum as the conducting material for micro devices.
1192-1194
Fur-
thermore, silicon technology will play an important role in molecular engineering
and nano technology which will emerge as a dominant industry in the 21th
century.
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Research on electrochemical properties of silicon is essential for
understanding and development of wet processes that can control surface conditions
and generate micro and nano surface structures, dissolved or deposited, of increasing
complexity.
The second reason is due to the importance of silicon material in the advance-
ment of solid state physics and material science. There is a huge existing knowledge
base and high degree of standardization and availability associated with silicon as a
material. Such knowledge base, standardization, and availability, which do not exist
with any other material, are essential for large scale researches into deeper questions
that cannot yet be asked for other materials. In fact, the current investigations on silicon
electrodes routinely cover almost the whole dimensional range from the scale of the
electrode to the atomic scale. New phenomena will be discovered and new knowledge
will be generated at deeper levels and wider scopes on silicon electrodes. There are
many topics that are of interest for further research, specifically, for example,
devices.
1. the chemical and electrochemical characters of hydrogen reaction
2. surface structural condition and kinetic processes for the formation of a
silicon-oxygen network that passivate the surface
