4.4 Extended Defects
93
Fig. 4.35 TEM images in two magnifications of a 3 {112} boundary in silicon together with a schematic of the atomic
arrangement. Adapted from [358]
Fig. 4.36 Monoatomic step on the Si (001) surface and subsequent formation of an antiphase boundary in InP
(zincblende)
4.4.4 Antiphase and Inversion Domains
Antiphase domains occur when one part of the crystal is shifted with respect to another by an antiphase
vector p. This does not form a twin. If the polar direction changes between two domains they are called
inversion domains.
In the zincblende structure the [110] and [ ¯
110] directions are not equivalent. In one case there is a
Zn-S lattice and in the other a S-Zn lattice. Both lattices vary by a 90
◦ rotation or an inversion operation
(which is not a symmetry operation of the zincblende crystal). If, e.g., a zincblende crystal is grown on
a Si surface with monoatomic steps (Fig. 4.36, cmp. Fig. 11.6), adjoint regions have a different phase;
they are called antiphase domains (APD). The antiphase vector is (0, 0, 1) a 0 /4. At the boundaries a
two-dimensional defect, an antiphase domain boundary, develops. The APD boundary contains bonds
between identical atom species. In Fig. 4.37, intertwining APD boundaries are shown on the surface
of InP layers on Si. The antiphase domains can be visualized with an anisotropic etch.
In Fig. 4.38a, inversion domains in iron-doped ZnO are shown. Between domains the direction of the
c-axis is reversed. The iron is found preferentially in the inversion domain boundary (IDB) (Fig. 4.38b)
and plays an important role in its formation [364, 365].
93
Fig. 4.35 TEM images in two magnifications of a 3 {112} boundary in silicon together with a schematic of the atomic
arrangement. Adapted from [358]
Fig. 4.36 Monoatomic step on the Si (001) surface and subsequent formation of an antiphase boundary in InP
(zincblende)
4.4.4 Antiphase and Inversion Domains
Antiphase domains occur when one part of the crystal is shifted with respect to another by an antiphase
vector p. This does not form a twin. If the polar direction changes between two domains they are called
inversion domains.
In the zincblende structure the [110] and [ ¯
110] directions are not equivalent. In one case there is a
Zn-S lattice and in the other a S-Zn lattice. Both lattices vary by a 90
◦ rotation or an inversion operation
(which is not a symmetry operation of the zincblende crystal). If, e.g., a zincblende crystal is grown on
a Si surface with monoatomic steps (Fig. 4.36, cmp. Fig. 11.6), adjoint regions have a different phase;
they are called antiphase domains (APD). The antiphase vector is (0, 0, 1) a 0 /4. At the boundaries a
two-dimensional defect, an antiphase domain boundary, develops. The APD boundary contains bonds
between identical atom species. In Fig. 4.37, intertwining APD boundaries are shown on the surface
of InP layers on Si. The antiphase domains can be visualized with an anisotropic etch.
In Fig. 4.38a, inversion domains in iron-doped ZnO are shown. Between domains the direction of the
c-axis is reversed. The iron is found preferentially in the inversion domain boundary (IDB) (Fig. 4.38b)
and plays an important role in its formation [364, 365].