EFFECTS OF SURFACE PREPARATION ON ION-IMPLANTATION IN GAAS

The influence of different polishing methods on the atomic profiles obtained by direct ion implantation in semi-insulating GaAs has been investigated, along with the effects of preimplantation etching. The results indicate that chem-mechanical polishing technologies, contrary to chemical only polishes, produce residual damage that results in shallower and more sharply peaked profiles. Polishing related damage, however, may not be the factor preventing a good electrical activation of implanted species. The acidity of the polishing fluid seems more important in determining the activation. Also, the dose implanted in uncapped, damaged wafers seems to be different, and generally lower, than the dose measured by the implanter.