Damage formed by low-dose Si+ implantation is studied. Variation of da
mage density with dose in Si+ implantation at 50 keV is measured at do
ses from 3.0 x 10(10) to 1.0 x 10(14) ions/cm(2) by the photoacoustic
displacement (PAD) technique. A close correlation has also been found
between the PAD value and ion implantation dose in low-dose ion implan
tation. Ion implantation dose can be monitored down to 3.0 x 10(10) io
ns/cm(2) by this technique. This dose detection limit is much lower th
an that of other methods. The in-depth damage profile can also be meas
ured by differentiating the observed PAD values with depth.