Fig. 1

Schematic representation of stereographic projection of {111} silicon: a (111) plane inside a unit cell, b unit cell at the center of a sphere which is used to project different crystallographic planes on 2D surface, and c stereographic projection exhibiting different planes. The {111} planes projected from the top and bottom hemispheres are shown by solid and open blue circles, respectively. Three {111} planes shown by blue color dots make an angle of 109.5º to the silicon wafer surface plane and 60º with each other, while another three {111} planes indicated by open blue circle form an angle of 70.5º to the surface plane and 60º to each other