Figure 1 - Electrochemcial etched Macropores in n-type Silicon
Figure 1 - Electrochemcial etched Macropores in n-type Silicon
This mircograph shows an overview on macropores and dendritic pores (break-through-pores) on n-type-silicon
etch under backside.illumination. It is obviously that the dendritic pores growth anisotropic - the growth-direction is the <100>-direction.
The macropore-walls show (111)-facetts. This facetts can be explained in the modell for macropore-formation as surface
with an slow kinetic for H-termination.
Figure 2 - Pore walls (n-type silicon)
At the tips of the dendritic-pores Spannunsgkonstrate were found. It was shown with EDX-analyse that an silicon-oixde was build
at the pore tips. The oxid-formation is an part of the formation modell.
Figure 3 - Contrast at pore tips
The dendritic pores were formed by intercalating (111)-oktaeder. The (111) is the plane with the lowst kinetic for the passivation.
Figure 4 - The dendritic pores
The dendritic pores were formed by intercalating (111)-oktaeder. The (111) is the plane with the lowst kinetic for the passivation.
Figure 5 - A schematic picture of an dendritic pore.
A schematic picture of an dendritic pore. The (111)-okteader were shown. The size of the oktaeder should by a function of the etch-potential and the H-concentration.
Figure 6 - Electrochemcial etched Macropores in p-type Silicon
We have published the first TEM-mircographs on macropores in p-type-silicon.
This micrograph shows macropores on p-type-silicon in plane-view. The pores were filled with mesoporous silicon. The lack of the oxidizing
reagent causes this filling (see theorie-part).
The pore-tip of a macropore in p-type.silicon etched in Acetonitril and HF. The inhomogenious pore tips hints to an inmhomogenious formation-reaction
at the tip. This mircographs shows the current-burst at the tips.
Figure 7 - Macropore tip in p-type Silicon
Figure 8 - Macropore walls (p-type Silicon)
Corresponding to n-type-silicon (111)-facetts were found at the pore-walls on macropores in p-type-silicon. The (111) is the surface with the lowst passigvation velocity.