In this work، anisotropic silicon etch using KOH ، optical microscopic and X-ray
diffraction testing، were used to determine the crystal orientation of the silicon
wafer(100) plane , where the mechanical polishing and wet etching described the
geometric dislocations pits which refers to the crystallographic and the level of
(100).
Microscopic examination have been described the geometric dislocations pits
which reflected from plane (100) in the forms of four fold flat symmetry which
refers to that plane in Silicon wafer, as the distribution of Miller Indices in the
cubic system, by the impact chemical wet KOH with concentration 30 wt%, and
an etching temperature of 70°C.
The crystal orientation of silicon wafer has been changed from (100) to (111)
plane, by chemical wet KOH through cutting 54,7°, the dislocations pits appear in
geometric forms in conical shape which refers to the direction [111] for silicon
wafer، by the impact chemical wet KOH with concentration 44 wt%, and an
etching temperature of 120°C for 20-30min
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