Zusammenfassung
Defect evaluation of silicon carbide (SiC) wafers can be accomplished
by potassium hydroxide (KOH) etching. The method described in this
work employs etching by KOH in a vapor phase rather than in a liquid
phase and this method allows reliable etching of both Si- and C-faces
and furthermore it allows the delineation of defects on alternate
orientation planes of SiC. Polished SiC wafers were etched in the
temperature range from 700 to 1000?C at atmospheric air pressure.
Etch pits were observed on (0001), (0001), (1120) and (1100) planes.
The shape of the pits was found to be in accordance with the crystallographic
symmetry. Activation energies for (0001) and (1120) planes were found
to be 17 kcal/mol and 20 kcal/mol, respectively. It was demonstrated
that the method of KOH vapor etching of SiC is simple for implementation
having possibilities to reveal most of the important crystal defects.
Nutzer