Chemistry Reference
In-Depth Information
between the two species across the interface. Several kinds of dipoles exist at the
interface: dipoles due to the formation of various interface bonds, dipoles due
to the presence of dangling bonds, and dipoles due to impurities at the interface. Accord-
ing to Massoud,
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all elements and compounds of interest have electronegativities larger
than that of silicon. Also, the partial charge transfer occurring between silicon and these
species generates dipoles with the positive charge on the silicon side of the interface
and the negative charge on the oxide. Table 3.3 lists the charge transfer for a variety of
silicon compounds. The electronic properties such as the flatband potential can be
altered by the presence of the dipoles at the interface. Assuming all the silicon are
bonded to molecules, the difference of flatband potential of (100) and (111) sur-
faces is calculated to be 0.476 V due to their difference in bond density and bond angle
to the
interface.
3.5.2. Electrical Properties
The electrical properties of silicon oxide play a critical role in many phenomena
on silicon electrodes, particularly in the growth of anodic films. Anodic oxides can
