The effect of dose and energy on postannealing defect formation for high en
ergy (mega-electron-volt) phosphorus implanted silicon has been studied usi
ng etch pit studies and transmission electron microscopy (TEM). Previous wo
rk has shown that after annealing there is a strong dependence of dislocati
on density threading to the surface on the implanted phosphorus dose and en
ergy. A superlinear increase in threading dislocation density (TDD) with im
plant energy between 180 and 1500 keV is observed for a dose of 1x10(14) cm
(-2). In addition as a function of ion fluence, there is a maximum in the t
hreading dislocation density at a dose of 1x10(14) cm(-2) followed by a rap
id decrease in TDD. Both the superlinear increase in TDD with increasing en
ergy and the rapid decrease with increasing dose have been further investig
ated by TEM. A TEM study of these higher doses revealed formation of a stro
ng bimodal loop distribution with small loops averaging < 1000 Angstrom and
large loops averaging around 1 mum in size. Over the dose range of 1x10(14
) cm(-2) to 5x10(14) cm(-2), the superlinear decrease in TDD from 1x10(6) c
m(-2) to < 1x10(4) cm(-2) coincides with the superlinear increase in small
dislocation loops from below 1x10(6) cm(-2) to above 1x10(10) cm(-2). It is
suggested that the homogeneous nucleation theory can explain many of the r
esults. However, the chemical presence of phosphorus appears to also play a
n important role in the formation of the small dislocation loops and possib
ly threading dislocations. (C) 2001 American Institute of Physics.