Controlled Growth of Ni Particles on Si(100)1a

Ni particles were grown on Si(100) by MOCVD from Ni(η 5 -C 5 H 4 Me) 2 in the presence of H 2 . There is an induction period which is a function of the precursor flux. The Ni particle size is a function of the deposition time and precursor flux. For example, with precursor held at 47 °C, the particle size increases from 140 nm (5 min) to 180 nm (10 min) to 260 nm (20 min) as the deposition time is increased. TiCl 4 surface treatment (a) and gas-phase addition of H 2 O (b) were explored further to influence growth. Both methods increase the growth rate as measured by the Ni(111) XRD peak intensity. (a) The TiCl 4 reacts with surface OH groups to form TiO 2 islands which act as nucleation sites for Ni growth. A 5 min exposure to TiCl 4 results in large (1 mm) amorphous and oriented crystalline TiO 2 islands. The Ni crystals first saturate the TiO 2 islands and then break off to form individual islands. (b) The gas-phase addition of H 2 O into the carrier gas stream results in initial formation of large particles which later break up into smaller particles. The size and number of particles are functions of the concentration of H 2 O in the gas phase.