Reactive Deposition of Cobalt and Nickel Films from Their Metallocenes in Supercritical Carbon Dioxide Solution

Abstract

High-purity Co and Ni thin films were deposited directly onto the native oxide of Si wafers and onto TaN and TiN films supported on Si wafers by the hydrogen reduction of their respective metallocenes in supercritical CO 2 solution using a batch, cold-wall chemical fluid deposition (CFD) reactor. For Co deposition from bis(cyclopentadienyl)cobalt, substrate temperatures ranged between 285 and 320 °C and reactor pressures were 220-260 bar. For Ni deposition from bis(cyclopentadienyl)nickel, substrate temperatures were 175-200 °C and reactor pressures were 190-230 bar. In all cases, the reactor wall temperatures were maintained between 90 and 120 °C, restricting the depositions to the heated substrates only. The deposited films were characterized by SEM, XRD, and XPS. The films were found to be essentially free from ligand-derived contamination.

A comparative study of copper thin films deposited using magnetron sputtering and supercritical fluid deposition techniques

“…All SFCD experiments were carried out in a stainless steel high pressure cold-wall reactor of 153 mL of internal volume operating in batch mode, as described by Hunde et al [17]. A resistively heated stage was placed in the center of the vessel.…”

Kinetics and Vapor Pressure Studies of bis(<i>N</i>-alkyl-2-hydroxonapthaldimine)nickel (II) (<i>N</i>-R = methyl to pentyl) Complexes

“…pentyl] The syntheses of bis(N-alkyl-2-hydroxonapthaldimine)nickel(II), where N-alkyl = methyl to pentyl complexes were carried out by treating the appropriate primary amines with the hot alcoholic suspension of Ni(2-hydroxonapthal) 2 . The resulting olive green solution was refluxed for about 0.5 h and the crystals formed were filtered, washed with ethanol and dried under vacuum.…”

“…Many publications warned the use of highly toxic Ni(CO) 4 as a precursor [8] [9], which was first used by Mond in 1885. Other precursors used in MOCVD of Ni films are Ni(acac) 2 en [1], Ni(tfacim) 2 (tfacim = triflouroacetylacetone-imine) [3] [4], Ni(L) 2 [L= dimethylglyoxime [10], diethylglyoxime, dipropylglyoxime [6]], Ni(η 5 -C 5 H 5 ) 2 [7], Ni(L) 2 [L = acetylacetone (acac) [11], hexafluoroacetylacetone (hfac) [12] and tetramethylheptanedione (tmhd) [13]]. Ni(tmhd) 2 [14] and Ni[(acac) 2 en] [1] met the requirements of an ideal precursors in CVD applications.…”

Cobaltocene adsorption and dissociation on Cu(111)

“…The surface chemistry of many metallocenes, M(C 5 H 5 ) 2 (M = Cr, Mn, Fe, Co, Ni) has been motivated by the possibilities of "direct writing" small magnetic features [1][2][3][4][5][6][7][8][9][10][11][12]. "Clean" magnetic features require the removal of the ligand species during decomposition, which may require the addition of hydrogen to the background, but the metallocene interaction with the substrate is also key.…”