In this paper, we report growth of AlN epilayers by pulsed atomic-layer epitaxy (PALE) method, by which the group III
element sources and NH3 were alternatively transported into the reactor. We have systematically investigated the effects
of growth conditions of PALE on the crystal quality of AlN epilayers. By optimizing the PALE growth conditions, the
root mean square (rms) of AlN layers was 1.319 nm and the full width at half-maximum (FWHM) was 0.18 arcmin,
room-temperature band edge absorbing peak at 198 nm was easily achieved, indicating the small mosaicity and low
dislocation density of the films.