Mechanism of Ni Film CVD with a Ni(ktfaa)₂ Precursor on a Copper Substrate

Abstract

The mechanisms of pyrolysis in He and reduction in H 2 of a Ni(ktfaa) 2 chelate and nickel film deposition on copper substrates are discussed. The Ni films produced by CVD with the Ni(ktfaa) 2 chelate as a precursor are continuous. Pyrolysis of the Ni(ktfaa) 2 chelate takes place above 300 C. The hydrogen atmosphere allows the reaction temperature to be decreased to 213 C, but the film deposition rate is low. 300 C is the optimal temperature for continuous Ni film deposition on Cu substrates. The mechanism of hydrogen interaction with the adsorbed Ni(ktfaa) 2 chelate is discussed.

Mechanism of Ni Film CVD with a Ni(Ktfaa)2 Precursor on a Silicon Substrate

“…Besides, the peak is slightly shifted towards a higher value of h with a temperature rise up to 280 C. The peak maximum position, unchanged in the range 280±310 C is shifted towards lower values of h at a higher temperature. As has been shown, [6] Ni(ktfaa) 2 chelate pyrolysis is observed at temperatures > 300 C. This means that carbon-containing by-products produced in the gas phase close to the substrate surface result in carbon incorporation into the Ni deposit. This leads to a unit cell enlargement and shifts the peak position to the lower value of h. [8] We can see the peak intensity decrease at 335 C but the film thickness is more than that at 310 C. Since the run time of the film deposition was the same for different conditions of the procedure, the amount of the Ni phase decreases at 335 C, but C-containing incorporation increases.…”

“…The film thickness is substantially less than on Cu substrates. [6] The films are clustered at low temperatures: the cluster size is around 510 ±2 lm and the distance between clusters is much larger. The surface between clusters is very smooth without any visible deposits.…”

“…The metallic surface is preferred for the chelate reduction because of the catalytic dissociation of H 2 molecules on a Ni surface. [6] The adsorption energy of Figure 3 shows the X-ray diffraction (XRD) data of the Ni films deposited at various temperatures in a H 2 /He mix. Attention was focused on the Ni(111) peak because the films were very thin and other reflections were very weak.…”

“…Island-like films, usually a result of physical vapor deposition, [4] are often observed when CVD is used in the case of insulator substrates. [5] In this study, bis(2-imino-pen-en-4-trifluoro-acetylacetonato)Ni II , Ni(ktfaa) 2 , discussed previously in detail for the process on copper substrates, [6] was used as a precursor for the CVD of Ni films on silicon substrates. The goal of this paper is an extension of an understanding of the mechanism of nickel film deposition with the Ni(ktfaa) 2 precursor on Si in inert (He), or reduction (H 2 ), gases.…”

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

“…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.…”