On defects created in 45 keV H −-implanted n-type Cz Si: a fluence dependence and isochronal annealing study

Abstract

Five electron traps E1 ( E C=0.17 eV), E2 ( E C=0.22 eV), E3 ( E C=0.29 eV), E4 ( E C=0.43 eV), and E5 ( E C=0.50 eV) were created in n-Si by 45 keV H − implantation. E1 (VO–centre) and E2 (V 2 2−/−) increased linearly with fluence in the range 5×10 10–1×10 12 cm −2, while the hydrogen-related defects E3 (VO–H) and E5 showed a quadratic fluence dependence. E4 also exhibited a quadratic fluence dependence, which could be characteristic of overlapping traps, including VP, V 2 −/0, VH, and V 2H. The ratio E3 : E1 showed sign of saturation at the higher fluences, whereas E5 : E2 increased monotonically with the increasing fluence. E3 and E5 increased with the annealing temperature at the expense of E1 and E2, respectively, up to 200°C, but without a one-to-one correlation. Two secondary defects E6 ( E C=0.20 eV) and E7 ( E C=0.49 eV), which we propose to be higher-order vacancy clusters, were observed above 350°C.