Titanium cyclopentadienyl organometallic complexes have been proposed as potential titanium MOCVD Precursors: titanocene “Ti(η 5-C5H5)2“ (or “TiCp2”), as well as alkyne adducted titanocenes Ti(η5-C5H5)2(η 2-RC≡CR).
Titanocene as MOCVD Precursor
Many patents claim the use of Ti precursors in the CVD process, however, only few analytical data are available of high-purity Ti coatings.
For example, “Ti(η5-C5H5)2“ was tested as CVD precursor fior thwe growth of Ti films. However, even when an H2 plasma the obtained layers contained mainly C, what was attributed to the cyclopentadienyl ligands.
Under H2: Ti(η5-C5H5)2 + n H2 → Ti(s) + 2 C5H5+n(g) (n = 1, 3, 5)
Dissociation of Cp organic units on the metal surface leads to significant carbon contamination as well as formation of TiC. In the absence of H2: the initially formed C5H5* radical can react to produce dihydrofulvalene or reacts heterogeneously to incorporate in the growing metal film.