Compound semiconductor modified surface by use of pulsed electron beam and ion implantation through a deposited metal layer

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 ).