We study effects of deposition temperature on growth mode and surface morphology
of hetero-epitaxial (ZnO)x(InN)1-x (ZION) films on ZnO
templates. ZION films deposited at low temperature of RT-250oC grow
two dimensionally, whereas ZION films deposited at high temperature of
350-450oC grow three dimensionally. Growth mode is changed from
two-dimensional growth mode to three-dimensional one, because the critical
thickness where film strain begin to relax decreases with increasing the
deposition temperature. At high deposition temperatures, the number of point
defects in ZION films decreases because migration of adatoms on the growing
surface is enhanced. The strain energy in ZION films increases with increasing
the deposition temperature, since the strain energy is not released by point
defects. Therefore, lattice relaxation for the higher deposition temperature
begins at the smaller film thickness to release the strain energy. As a result,
ZION films with atomically-flat surface were obtained even at RT.