ABSTRACT
Figure 1.3 Unit cell of a GaAs crystal and as two fcc lattices. Crystal growth and etching behavior of solids can be better explained if the structure in different directions and along different planes is well understood. Figures 1.4 and 1.5 show the zinc-blende unit cell truncated along the face diagonal and the body diagonal. The terminology of Miller indices is used to describe directions at planes within the crystal. A set of three integers enclosed in square brackets is used to specify direction in the lattice. [abc] defines a direction whose vector is ax^ + by^ + cz^, where x^, y^, and z^ are unit Cartesian vectors along x, y, and z. Surfaces perpendicular to [abc] are designated as (abc). Some common crystalline directions and planes are shown in Fig. 1.4. Also, <abc> indicates a family of [abc] directions that are equivalent. {abc} indicates a family of planes equivalent to (abc).
