The structural changes produced in the near-surface region of single-crysta
l Si upon fabrication of delta back-surface-field devices were studied by x
-ray diffraction in an offset-asymmetric geometry. The results demonstrate
that implantation of 180-keV P+ ions into Si with a dose on the order of 10
(15) cm(-2), followed by thermal annealing, allows buried amorphous Si laye
rs to be produced. The structures thus prepared suffer a significant lattic
e strain perpendicular to the interface.