Location of Trapped Charge in Aluminum-Implanted SiO2

The position of the centroid of electrons trapped on sites resulting from aluminum implantation into SiO
2
is measured by using the photo I–V technique for energies from 15–40 keV, oxide thicknesses from 49–140 nm, and post-implant annealing temperatures from 600–1050°C in N
2
for 30 min. The centroid of the trapped electrons is found to be identical to that of the implanted aluminum from SIMS measurements, regardless of annealing temperature from 600 to 1050°C, and located closer (by less than 9 nm) to the Al-SiO
2
interface than predicted from the Lindhard-Scharff-Schøtt (LSS) calculations of Gibbons, Johnson, and Mylroie. Comparison of centroids determined from photo I–V and SIMS measurements as a function of SiO
2
thickness also implies that the distributions of the ions and negative trapped charge are the same. The trapping behavior of these sites is discussed in the accompanying paper by Young et al.