Thermally sensitive at elevated, near
melting point temperature,
compound semiconductor materials single crystals including Group III-
Nitride, other Group III-V,
Group II-VI and Group IV-IV are produced by a variety of methods. When produced as
single crystal layers by
epitaxy methods or is necessary to
expose them to elevated temperatures or
ion implanted to the non crystalline state, or their electrical or optical properties are modified, large numbers of
crystal defects on the atomic or
macro scale may be produced, which limit the yield and performance of opto- and electronic devices constructed out of and grown on top of these
layers. It is necessary to be able to improve the
crystal quality of such materials after being exposed to elevated temperature or
ion implanted or modified by the presence of impurities. It is necessary, particularly for opto- and electronic devices that only the surface of such materials is processed, improved and thus the modified surface product. Generally, as shown in FIG. 1, the thermally sensitive
compound semiconductor layer is first coated with a
metal layer of approximate thickness of 0.1 microns. Next, the volatile component of the
compound semiconductor is
ion implanted through the
metal layer so as to occupy mostly the top 0.1 to 0.5 microns of the compound
semiconductor layer. Co-implantation may be used as well to improve the surface. Finally, through a pulsed directed energy beam of electrons with a
fluence of approximately 1
Joule / cm2, the top approximately 0.5 microns acquire a level of the deposited
metal and are converted into a
single crystal with improved properties such as reduced defect density and or electrical
dopant (FIG. 1).