We report on the lattice location of ion-implanted Cu-67 in p(+)- and n(+)-Si using the emission channeling technique. Following room-temperature implantation, the majority of Cu was found on near-substitutional sites in both p(+)- and n(+)-Si. Annealing in the temperature range 200-600 degrees C resulted in changes of near-substitutional Cu to random sites in p(+)-Si, while in n(+)- Si all of the near-substitutional Cu was converted to ideal substitutional lattice sites. The activation energy for dissociation is estimated to be 1.7-2.0 eV for near-substitutional Cu in p(+)-Si and 2.9(2) eV for ideal substitutional Cu in n(+)-Si. (C) 2000 American Institute of Physics. [S0003-6951(00)02640-1].