Trans-projected-range gettering of copper in high-energy ion-implanted silicon

Strong gettering of Cu atoms beyond the projected ion range Rp has been fou nd in single-crystal Si implanted with P+ and As+ ions at MeV energies. We call this phenomenon the "trans-R-p effect." The formation of a separate Cu gettering band below R-p, as detected by secondary ion mass spectrometry, indicates the presence of a significant amount of defects therein. These de fects-have not been detected by transmission electron microscopy and we sug gest that they are small interstitial clusters. The amount of Cu atoms gett ered beyond R-p is, particularly for the P implants, much greater than that in the gettering layer at R-p, indicating that the gettering ability of th e point defects beyond R-p is higher than that of the extended defects at R -p. A mechanism responsible for their formation and clustering in the trans -R-p region is proposed, and an explanation is given of the differences in the results for the P and As implants. (C) 2000 American Institute of Physi cs. [S0021-8979(00)01221-4].