REAL-TIME X-RAY TOPOGRAPHY OF GAAS AND HGCDTE EPITAXIAL FILMS AND/ORVARIOUS SUBSTRATES

WITH THE DOD HGCDTE AND GAAS PROGRAMS MOVING TOWARD EPITAXIAL GROWTH TECHNOLOGY THERE IS A NEED TO DEVELOP REAL-TIME MATERIALS CHARACTERIZATION TECHNIQUES OF BOTH SUBSTRATES AND/OR EPITAXIAL FILMS QUICKLY FOR PRODUCTION ENVIRONMENTS. REAL-TIME X-RAY TOPOGRAPHY OF WHICH BRIMROSE IS A PIONEER IS ONE METHOD OF CHARACTERIZING THESE MATERIALS INSTANTLY BEFORE COSTLY PROCESSING IS PERFORMED ON POOR MATERIALS. INITIAL RESEARCH AND DEVELOPMENT EFFORTS WHICH HAVE BEEN INTERNALLY FUNDED AND NAVY FUNDED HAVE SHOWN THAT X-RAY TOPOGRAPHY IS FEASIBLE FOR INVESTIGATING BOTH BAF2 SUBSTRATES AND PB SALT EPITAXIAL FILMS ON 1 X 1 CM2 AREA DEVICES. HOWEVER, THIS TECHNIQUE IS NOT LIMITED TO SUCH SMALL AREA DEVICES. RECENTLY 6 X 6 IN2 CAST SILICON WAFERS HAVE BEEN INVESTIGATED BY REAL-TIME X-RAY TOPOGRAPHY. ALSO, X-RAY TOPO GRAPHY IS A GOOD METHOD OF LOCATING DEFECT AREAS IN BULK EPITAXIAL FILMS AND/OR SUBSTRATES WHICH CAN BE LATER INVESTIGATED BY HIGH RESOLUTION TEM AND EBIC TECHNIQUES.