X-RAY-DIFFRACTION PATTERNS IN HIGH-ENERGY PROTON-IMPLANTED SILICON

Silicon crystals implanted with 1 and 1.6 MeV protons were studied by means of conventional source double-crystal and synchrotron multi-crys tal arrangements. Both the rocking curves and series of topographs wer e recorded in different parallel settings employing different reflecti ons and wavelengths of radiation. A comparison of rocking curves in di fferent regions of implanted areas was performed in synchrotron multi- crystal arrangement with a beam of a very small diameter. The rocking curves exhibited subsidiary interference maxima with increasing period icity on the low angle side. The plane wave topographs taken at differ ent angular setting revealed characteristic fringes whose number decre ased with increasing distance from the main maximum. The fringe patter n did not depend on the direction of the diffraction vector. The numbe r of fringes for equivalent angular distance from the maximum was larg er for higher order of reflection. The shape of the rocking curve and other diffraction patterns were reasonably explained assuming the latt ice parameter change depth distribution proportional to the profile ob tained from the Biersack-Ziegler theory and lateral non-uniformity of ion dose. A good approximation of the experimental results was obtaine d using numerical integration of the Takagi-Taupin equations.