Redistribution of implanted Er in SiO2 on Si studied by combined transmission electron microscopy and Rutherford backscattering analysis

850 nm thick silica on [100] Si was implanted with 300 keV Er ions. RES pro files of as-implanted Er yielded mean depths (d) over bar of 105 nm and 85 nm for doses of 2.1 x 10(16) cm(-2) and 8.2 x 10(16) cm(-2), respectively. Annealing at 1200 degrees C for 4 h gave (d) over bar of 169 nm and 85 nm f or low and high dose. After 1275 degrees C 4 h anneal for the high dose (d) over bar was 98 nm, for the low dose 2 peaks developed with (d) over bar o f 332 nm and 694 nm, XTEM at the low dose samples showed Er containing incl usions of mean radii 19.2 nm (1200 degrees C) and 27.1 nm (1275 degrees C) with similar Er depth distributions as those measured by RES. A diffusion a nd transport mechanism of precipitates driven by strain induced by radiatio n damage during implantation and thermal expansion is proposed. (C) 1999 El sevier Science B.V.