Titanium trichloride dimethylamide (or trichloro(dimethylamino)titanium) TiCl3(NMe2) has vapor pressure ~2 Torr at 100° C, it is liquid at 73°C bubbler temperature.
TiCl3(NMe2) was applied for the ALD growth of TiN thin films; the layers were reported to exhibit resistivities of about 150 to 200 µΩ·cm – way lower than films deposited from Ti(NMe2)4 which were much less conductive (resistivities 5,000-50,000 µΩ·cm. The films grown using halide amino metal precursors contained lower concentrations of Cl in the film compared to TiN layers deposited with TiCl4.
TiN growth by ALD using TiCl3(NMe2): The TiCl3(NMe2)
precursor (evaporated at 73°C, carrier gas 10sccm He) and NH3 co-reactant (100sccm) were pulsed alternately into the deposition chamber maintained at 295° C temperature and 0.01 Torr pressure. The pulse times were 2.0 seconds for TiCl3(NMe2), 2 sec
Ar purge (200 sccm), 1 sec NH3 pulse, 3 sec Ar purge (200 sccm). The TiCl3(NMe2)/purge/NH3/purge cycles were repeated till 100 nm TiN film was formed. SIMS analysis for chlorine (37Cl isotope) revealed a spike in Cl concentration from ~40 to ~100 nm, the spike
does not reach the high level for TiN films grown by ALD using TiCl4 , and overall Cl concentration was much lower.[[i]]
[i] B.A. Vaartstra, D. Westmoreland, E.P. Marsh, S. Uhlenbrock, US7250367B2, 2007, “Deposition methods using heteroleptic precursors”, https://patents.google.com/patent/US7250367B2/en
Even though TiCl3(NMe2) showed positive test results, additional testing revealed a potential preference for trichloro(diethylamino)titanium (IV) TiCl3(NEt2) , which is more thermally stable and has reasonable vapor pressure ~0.28 Torr/ 75° C.