Chemistry Reference
In-Depth Information
In nonfluoride acids such as solutions, the anodic current is due to the
formation and thickening of the oxide film.
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Addition of fluoride species to these
solutions results in
i-V
behavior similar to that in HF solution.
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5.2.2. Alkaline Solutions
The anodic behavior of silicon electrodes in alkaline solutions is characterized
by the formation of an oxide film and passivation of the surface. Typical
i-V
curves of
n-
and
p
-type silicon in KOH solution are shown in Fig. 5.9.
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Silicon surface is pas-
sivated at an overpotential marked by a small current peak. The potential at the current
peak is called the passivation potential,
and in the systems shown in Fig. 5.9 it
is -0.92 and
for
n-
and
p
-type silicon, respectively. The small current at
