Ion implantation followed by rapid thermal annealing is used to induce layer
intermixing and thus selectively blue-shift the emission wavelength of
InP-based quantum well hetero- structures. The intermixing is greatly
enhanced over thermal intermixing due to the supersaturation of defects. The
magnitude of the observed blue-shift has been studied previously as a
function of ion fluence and ion mass: the dependence on ion mass is well
established, with heavier ions producing a larger shift. We show here that
chemical effects can also play a significant role in determining the induced
blue-shift. Data are presented from the implantation of the similar mass
ions; aluminum (m~27), silicon (m~28) and phosphorus (m~31). The P- induced
blue shift displays a monotonic increase with fluence, consistent with
previous studies; however, the fluence dependence of Al- and Si-induced
blue-shifts both deviate significantly from the behaviour for P. These
results have important implications for attempts to scale intermixing
behaviour with ion mass.