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

Abstract

Ni particles were grown on Si(100) by MOCVD from Ni(η5-C5H4Me)2 in the presence of H2. 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. TiCl4 surface treatment (a) and gas-phase addition of H2O (b) were explored further to influence growth. Both methods increase the growth rate as measured by the Ni(111) XRD peak intensity. (a) The TiCl4 reacts with surface OH groups to form TiO2 islands which act as nucleation sites for Ni growth. A 5 min exposure to TiCl4 results in large (1 mm) amorphous and oriented crystalline TiO2 islands. The Ni crystals first saturate the TiO2 islands and then break off to form individual islands. (b) The gas-phase addition of H2O 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 H2O in the gas phase.

Incorporation of a Binary Alloy in an Oxide Matrix via Single Source Precursor CVD Process

“…In view of the above, we were interested in examining the decomposition behavior of a mixed-metal precursor where both metal constituents are prone to redox reactions. Keeping in view the broad range of applications of Ni containing materials, especially in high-density data storage devices and magnetoresistive sensors, , we have chosen a Ni−Sn heterometal alkoxide, [Ni 2 Sn 2 (O t Bu) 8 ], as precursor . The synthesis and structural characterization of [Ni 2 Sn 2 (O t Bu) 8 ] have been reported by us.…”

Synthesis of Ni nanoparticles with controllable magnetic properties by atmospheric pressure microplasma assisted process

“…This technique combines the advantages of microreactors and the nonthermal plasma chemistry, resulting in a new and facile route for the gas phase fabrication of Ni nanoparticles. Compared to the existing methods (Table 2 [33][34][35][36][37][38][39][40][41][42][43][44][45] ), the present study chooses Ni(cp) 2 as the precursor to replace the commonly used Ni(CO) 4 which is extremely toxic and dangerous. 36 As a consequence, special safety precautions are not needed.…”

Novel Nickel Precursors for Chemical Vapor Deposition

“…From its very first attempt the focus of chemical vapor deposition (CVD) of nickel has been to replace the very toxic nickel tetracarbonyl, Ni(CO) 4 , with a precursor that is less toxic . Ni(cyclopentadienyl) 2 , Ni(methylcyclopentadienyl) 2 , Ni(ethylenediamine)(hexafluoroacetylacetatonate) 2 , Ni(acetylacetonate) 2 , Ni(hexafluoroacetylacetonate) 2 , and Ni(diethylglyoximate) 2 have been proposed as alternative precursors to deposit Ni with hydrogen as a reducing agent. − Unfortunately, the Ni films deposited from these precursors often exhibited significant incorporation of impurities such as oxygen and carbon, even when hydrogen was employed as a reducing agent. Although it was reported that Ni(diethylglyoximate) 2 decomposed to produce pure nickel at a substrate temperature of 400 °C without H 2 , the breakdown of the ligands involved in thermal decomposition of the precursor is inherently prone to incorporating impurities in the deposited films.…”