T. Kanayama et al., Nanofabrication using structure controlled hydrogenated Si clusters deposited on Si surfaces, J VAC SCI B, 18(6), 2000, pp. 3497-3500
We studied structure formation by deposition of hydrogen-saturated Si clust
ers Si6H13+ and Si8H19+ on Si (111)-(7X7) surfaces using the deposition sys
tem of cluster ions equipped with a scanning tunneling microscope (STM) for
surface observation, The system uses a quadrupole ion trap as a mass-selec
tive source of cluster ion beams and delivers to the substrate a beam of Si
6H13+ focused to 2 mm diameter with a current of similar to 100 pA for the
cluster kinetic energy on impact with the surface >5 eV. It was observed th
at when these clusters are deposited with suitable kinetic energy, i.e., si
milar to2 eV/Si atom, the impact energy makes the clusters mobile on the su
rface, leading to self-formation of cluster-agglomerated structures at step
edges and along domain boundaries of (7X7) phases. Intentional manipulatio
n of the deposited clusters is also possible using the STM tip; the cluster
s can be accumulated to the tip position by applying bias voltage larger th
an 3 V. (C) 2000 American Vacuum Society. [S0734-211X(00)16306-1].