We have developed a process using electron beam lithography and reactive io
n etching for the high resolution pattern transfer of GaN. 150 nm dots have
been fabricated in GaN successfully. Photoluminescence, scanning electron
microscopy, and x-ray photoelectron spectroscopy have been employed to comp
are the damage inflicted on the GaN surfaces after SF6 and Ar plasma exposu
res. Near-band-edge luminescence analysis indicates the existence of a high
er concentration of donors on the top 100 nm of the GaN surface after Ar as
supposed to SF6 plasma exposure. An order of magnitude decrease in the rat
io of the yellow to the band-edge luminescence intensity is found in the sa
mples subjected to lower ion energies. Formation of pits is observed on the
substrate surfaces after plasma treatment. Nitrogen deficient surfaces lim
ited to the top few monolayers, as well as defect propagation down to 100 n
m, exist in our plasma exposed GaN samples. (C) 1999 American Vacuum Societ
y. [S0734-211X(99)10006-4].