Tetrakis(dimethylamido)titanium
Tetrakis(dimethylamido)titanium, often abbreviated as TDMAT, is a chemical compound with the formula Ti[N(CH3)2]4. It is a pale yellow liquid at room temperature and is an important precursor in metal-organic chemical vapor deposition (MOCVD) for the production of titanium nitride (TiN) and titanium dioxide (TiO2) thin films.
TDMAT is a member of the metal amido family of compounds, characterized by a metal-nitrogen bond. The four dimethylamido ligands surrounding the central titanium atom create a highly reactive molecule. This reactivity stems from the electron-donating nature of the amido groups and the tendency of titanium to form stronger bonds, particularly with elements like oxygen and nitrogen.
Due to its air and moisture sensitivity, TDMAT requires careful handling under inert atmosphere conditions. It readily reacts with water and oxygen, leading to decomposition and the formation of undesirable byproducts. Therefore, it is typically stored and handled in gloveboxes or using Schlenk line techniques.
In MOCVD processes, TDMAT is volatilized and transported to a heated substrate where it decomposes, depositing a thin film containing titanium. The composition and properties of the resulting film can be controlled by adjusting parameters such as substrate temperature, precursor flow rate, and the presence of other gases. For TiN deposition, a nitrogen source, such as ammonia (NH3), is often used in conjunction with TDMAT. For TiO2 deposition, an oxygen source, like oxygen gas (O2) or water vapor (H2O), is employed.
Beyond MOCVD, TDMAT has also found use in other chemical applications, including as a reagent in organic synthesis. However, its primary industrial application remains in the fabrication of thin films for microelectronics and other advanced materials.