Gettering of Cu and Ni in mega-electron-volt ion-implanted epitaxial silicon

Abstract

Gettering of Cu and Ni by 2.3 MeV Si ion-implantation-induced defects has been investigated in epitaxial silicon as a function of annealing temperature, time, and cooling rate. Secondary ion mass spectrometry revealed two distinct gettering regions, the position of which correlated with the ion projected range Rp and approximately half of Rp. Gettering experiments performed on samples with low metal impurity concentration have shown that capture of Cu and Ni in the two gettering regions occurred during high-temperature annealing, indicating a segregation-induced gettering mechanism. The binding energies of Cu and Ni are higher in the shallow Rp/2 region than in the Rp region.