  The mechanism of recrystallization in epitaxial (1000) GaN film, introduced
by indentation technique, is probed by lattice dynamic studies using Raman
spectroscopy. The recrystallized region is identified by Micro-Raman area
mapping. Pop-in bursts in loading lines indicate nucleation of dislocations and
climb of dislocations. These processes set in plastic motion of lattice atoms
under stress field at the center of indentation for the initiation of
recrystallization process. A planar defect migration mechanism is evolved. A
pivotal role of vacancy migration is pointed out, for the first time, as the
rate limiting factor for the dislocation dynamics initiating the
recrystallization process in GaN.
