Hf or Au implantation into SiO2 by electron irradiation

Bilayer films of Hf(target atom)/SiO2(substrate) and of Au/SiO2 were irradiated with 2 MeV electrons in an ultra-high voltage electron microscope, with the electron beam incident on the target metallayer. With this irradiation, hafnium atoms are successfully implanted into the SiO2 substrate, and nm-sized particles of HfO2 are formed, being dispersed in an amorphous silicon oxide matrix. On the other hand, no evidence for the implantation of gold is obtained even after prolonged irradiation. Based upon these results, the factors controlling the ease with which foreign atoms are successfully implanted into the SiO2 substrate under MeV electron irradiation are discussed. (author)