DETERMINATION OF BORON IN THE THIN SURFACE-LAYER OF A SILICON-WAFER BY INSTRUMENTAL CHARGED-PARTICLE ACTIVATION-ANALYSIS

Instrumental charged particle activation analysis (CPAA) for determini ng boron in a thin surface layer of silicon was developed. The nuclear reaction and incident energy were selected in order to minimize any i nterference from surface or bulk impurities. Thin boron film was used as a standard sample and its boron content was determined by neutron i nduced prompt gamma-ray analysis. As a result, we were able to determi ne B-11 and B-10 at 10(15) atoms/cm(2) with an accuracy of better than 3% by 4 MeV proton and 7 MeV alpha-bombardment, respectively, Each bo ron isotope could be determined down to 10(13) atoms/cm(2). Our CPAA w as applied to determine boron in a boron implanted silicon wafer of a SIMS standard sample.