The channeling effect technique employing both 1.8 MeV helium and 450 keV proton analyzing beams was used to extract disorder distributions for 200 keV and 300 keV boron implanted s of the minimum yield from single crystal substrates underlying surface amorphous layers. A simple description of the interactions of the analyzing beam in partially disordered samples was acceptable for obtaining the disorder peak depth and shape when applied to both helium and proton backscattering spectra. For samples held at temperatures below -45°C during implantation of between ~2 x 1014 and ~8 x 1014 boron ions/cm2, plural scattering gave self consistent results for the dechanneling mechanism. An essentially phenomenological multiple scattering treatment of dechanneling was also given for the analysis of room temperature implants. The mechanism governing the dechanneling was shown to depend on the detailed structure of the disordered layer, so an all-inclusive treatment of backscattering spectra to extract arbitrary disorder distributions was not feasible at the present time.
The measured results for the disorder peak depths agreed well with the values for these depths calculated by D.K. Brice, but were 80-85% less than the boron projected range. The measured disorder peak widths were 60-70% less than the calculated values.
The amount of disorder in samples held at room temperature during implantation was about a factor of twenty less than that in samples implanted at -150°C with the same dose of boron ions. Comparison of the disorder production data with the anneal of a -150°C implant showed the nonequivalence of dynamic anneal processes at a given temperature and thermal instabilities of disorder produced at lower temperaturesand then warmed to the given temperature.
It was shown that analyzing beam bombardment could effect the amount of disorder measured.
The depth scale of the backscattering spectra was determined directly by layer removal. The composition of the anodic oxide layers employed in the layer removals was measured by a backscattering analysis. Stopping power measurements were given showing that the aligned beam stopping power as measured by backscattering was ~80% of the random value at 1.0 MeV, an energy near the maximum of the random stopping power curve for helium in silicon.
