This comprehensive review is concerned with studies regarding ion implanted
gallium nitride (GaN) and focuses on the improvements made in recent years
. It is divided into three sections: (i) structural properties, (ii) optica
l properties and (iii) electrical properties. The first section includes X-
ray diffraction (XRD), transmission electron microscopy (TEM), secondary io
n mass spectroscopy (SIMS), Rutherford Backscattering (RBS), emission chann
eling (EC) and perturbed yy-angular correlation (PAC) measurements on GaN i
mplanted with different ions and doses at different temperatures as a funct
ion of annealing temperature. The structural changes upon implantation and
the respective recovery upon annealing will be discussed. Several standard
and new annealing procedures will be presented and discussed. The second se
ction describes mainly photoluminescence (PL) studies, however, the results
will be discussed with respect to Raman and ellipsometry studies performed
by other groups. We will show that the PL-signal is very sensitive to the
processes occurring during implantation and annealing. The results of Hall
and C-V measurements on implanted GaN are presented in Section 3. We show a
nd discuss the difficulties in achieving electrical activation. However, op
tical and electrical properties are both a result of the structural changes
upon implantation and annealing. Each section will be critically discussed
with respect to the existing literature, and the main conclusions are draw
n from the interplay of the results obtained from the different techniques
used/reviewed. (C) 2001 Elsevier Science B.V. All rights reserved.