Argon ions were implanted either prior or subsequent to an ion implantation of boron into silicon wafers. After isochronal annealing at temperatures ranging from 500 to 900 °C, the samples were examined by a spreading resistance‐carrier concentration profile and secondary ion mass spectroscopy. It is shown that argon implantation at a dose sufficient to produce an amorphous layer inhibits the electrical activation and diffusion of boron implanted in silicon.