Effects of MOCVD Thin Cobalt Films' Structure and Surface Characteristics on their Magnetic Behavior

Abstract

Cobalt thin films are deposited by metal-organic (MO)CVD, under various experimental conditions, on Si and SiO 2 substrates. The precursors used are cobalt nitrosyl tricarbonyl, Co(CO) 3 NO, cobalt acetylacetonate, Co(acac) 2 , and cobalt carbonyl, Co 2 (CO) 8 . Emphasis is given to the delivery method of each precursor, especially to a new technique of aerosol delivery. The films are thoroughly examined in terms of microstructure and surface morphology in order to establish relevance to magnetic properties. It is found that Co films deposited from Co 2 (CO) 8 dissolved in dichloromethane are characterized by a high degree of planarity and purity, while exhibiting a non-hysteretic giant magnetoresistance (GMR) behavior in the presence of an externally applied magnetic field normal to their surface.

Absolute cross sections for dissociative electron attachment and dissociative ionization of cobalt tricarbonyl nitrosyl in the energy range from 0 eV to 140 eV

“…2 The high volatility of Co 2 (CO) 8 and Co(CO) 3 NO make them suitable candidates for chemical vapour deposition (CVD), allowing the deposition of pure 3 or composite cobalt films for microelectronics and information technology. [4][5][6] With the advancement of nanotechnology tools and in particular focused electron beam induced deposition (FEBID) (for recent reviews on the method, see Utke et al 7 and van Dorp and Hagen 8 ), it has become possible to deposit more localized, three-dimensional structures. Cobalt octacarbonyl and cobalt tricarbonyl nitrosyl have thus been used in FEBID to deposit catalysts for carbon nanotube growth, 9 and to fabricate magnetic force microscopy (MFM) tips, 10,11 crossbar Hall nanosensors, 12 electrode contacts, 10 and cobalt nanowires.…”

Tribological characterization of chemical vapor deposited Co and Co 3 O 4 thin films for sensing reliability in engineering applications

“…Discrete peaks corresponding to typical Si angles of diffraction were detected (Fig. 1b), but this was, to some extent, attributed to the film's low thickness, which has been proven by AFM and MFM measurements (presented elsewhere [6]). The presence of peaks corresponding to Si angles can be attributed to the free from deposition wafer area that is left for many reasons, one of which is to directly measure the thickness of the thin film.…”

“…Then a solid inclusion complex (placed in a specialized glass reservoir) of β-cyclodextrin with CoI 2 was sublimed at 115 o C, and the vapors were introduced into the reactor with the aid of a constant O 2 flow of 50 ml/min; further details are reported elsewhere [6]. The thickness of the produced Co and Co 3 O 4 films ranged $ 120-150 nm.…”

“…In a typical experiment a liquid (solution) flow of 7 g/h was mixed with a hydrogen gas flow of 0.05 l/min at 27 1C. The mixture (aerosol) was then introduced to the reactor, the temperature of which had been adjusted to 140 1C; further details are reported elsewhere [6].…”

“…The films were grown in a vertical, cylindrical metallorganic CVD stainless steel reactor, specifically developed for the deposition of magnetic films, either singled or multilayered [5][6]. The reactor had computer controlled switching of gases for abrupt transients during deposition of multilayered structures.…”