Hexacarbonyl (Trimethylsilyl Ethyne) Dicobalt as MOCVD Precursor for Thin Cobalt Layer Formation

Abstract

The low melting Co0 source [Co2(CO)6(η2‐Me3SiC≡CH)] (3) was prepared as a precursor system for the metal‐organic chemical vapor deposition (MOCVD) of cobalt. The synthesis of 3 was realized by the reaction of trimethylsilyl acetylene (2) with dicobalt octacarbonyl (1) in n‐hexane at ambient temperature. Vapor pressure measurements and TG‐MS analysis were performed revealing the suitability of 3 in the CVD process. Cobalt layers formed in a vertical cold wall CVD reactor were characterized by SEM, EDX, and XPS. The appropriate metallic films consist of a mixture of cobalt and cobalt oxide.

Half-sandwich cobalt complexes in the metal-organic chemical vapor deposition process

“…The vapor pressure and thermal stability increases with an increasing number of P(OEt) 3 units as demonstrated by thermogravimetric measurements. The achieved vapor pressure of 3 is comparable to other cobalt containing CVD sources, such as dialkyl dicobaltatetrahedranes [39], and is reasonably higher than commonly used cobaltocene [39,40,47]. Hence, cobalt complex 3 was applied within the CVD process, while from 1 and 2 no layer could be deposited on the substrate within the used process parameters.…”

“…The respective vapor pressure traces of 1-3 are depicted in Fig. 1; for comparison, the established precursors cobaltocene and dicobaltoctacarbonyl were measured too [39,40,47,48]. The thermal behavior of 1-3 was additionally studied by thermogravimetric measurements (TG), and the results thereof are depicted in Fig.…”

A cobalt layer deposition study: Dicobaltatetrahedranes as convenient MOCVD precursor systems

“…*Previously published. 38 Table 1 Linear regression parameters of the vapour pressure measurements of 3a-i traces are highly dependent on the applied heating rate and hence low rates lead to predominant (up to complete) evaporation for all compounds studied. The heating rate was chosen to ensure that not only evaporation is monitored, but also decomposition temperatures can be estimated in order to get a hint for the substrate temperatures in the CVD process.…”

“…Scheme 1 Reaction of 1 with alkynes 2a-i forming dicobaltatetrahedranes 3a-i. *Previously published 38. Linear regression parameters of the vapour pressure measurements of 3a-i…”

Low-temperature chemical vapor deposition of cobalt oxide thin films from a dicobaltatetrahedrane precursor

“…1. The used precursor is characterized by a high vapor pressure of 26.3 hPa at 40 C. 34 Furthermore, the precursor is liquid at ambient temperature. These two properties lead to the fact that the precursor can be vaporized at a high rate with constant ow by simple technical means in contrast to the solid Co 2 (CO) 8 .…”