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

Abstract

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 /cm 2 , 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 ).

1 . A top surface modified compound semiconductor material product formed by a method comprising: 
 providing a layer of said compound semiconductor material, wherein said compound semiconductor material comprises a metal component and a non-metal component and said layer comprises a top surface;    placing said layer of said compound semiconductor material into a metal deposition tool and depositing a layer of metal component upon said top surface;    placing said layer of said compound semiconductor with said deposited layer of said metal component into an ion implantation tool and implanting non metal component into and through said metal layer;    placing said layer of said compound semiconductor with said deposited metal layer and said implanted non-metal component into a directed pulsed electron beam tool and exposing said layers to said energy beam.    
   
   
       2 . The product of  claim 1  wherein the said semiconductor material is a Group III-V material.  
   
   
       3 . The product of  claim 1  wherein the said semiconductor material is a Group II-VI material.  
   
   
       4 . The product of  claim 1  wherein the said semiconductor material is a Group IV-IV material.  
   
   
       5 . The product of  claim 1  wherein the said metal layer is a Group III element.  
   
   
       6 . The product of  claim 1  wherein the said metal layer is a Group I element.  
   
   
       7 . The product of  claim 1  wherein the said metal layer is a Group II element.  
   
   
       8 . The product of  claim 1  wherein the said metal layer is a transition metal.  
   
   
       9 . The product of  claim 1  wherein the said metal layer is a lanthanide metal.  
   
   
       10 . The product of  claim 1  wherein the said metal layer is any other metal in the periodic chart of elements.  
   
   
       11 . The product of  claim 1  wherein the said metal layer is a combination of two or more metals.  
   
   
       12 . The product of  claim 1  wherein the said metal layer is a combination of Group II and Group III on a Group III-V material.  
   
   
       13 . The product of  claim 1  wherein the said metal layer is a combination of Group I and Group II on a Group II-VI material.  
   
   
       14 . The product of  claim 1  wherein the implanted element is a non metal.  
   
   
       15 . The product of  claim 1  wherein the said implanted element is Nitrogen.  
   
   
       16 . The product of  claim 1  wherein the said implanted element is Carbon.  
   
   
       17 . The product of  claim 1  wherein the said implanted element is Silicon.  
   
   
       18 . The product of  claim 1  wherein the said implanted element is Oxygen.  
   
   
       19 . The product of  claim 1  wherein the said implanted element is any other nonmetal element of the periodic chart of elements.