A study on the real-time decomposition monitoring of a metal organic precursor for metal organic chemical vapor deposition processes

This study proposes a method for monitoring the decomposition state of a metal organic precursor which is used for the metal organic chemical vapor deposition (MOCVD) system. As many kinds of precursors for MOCVD such as tetrakis(dimethylamido)titanium (TDMAT) are highly likely to decompose due to the instability of their chemical structure during processing, critical problems are generated for thin film formation and its yield in this case. Although real-time monitoring technology on the decomposition degree of these precursors is essential for metallization, metal gate or electrode processes for memory devices, both commercialized technology and fundamental research have scarcely been accomplished. Therefore, this study endeavors for acknowledgment by the semiconductor industry with a proposal for a real-time monitoring method on the decomposition degree of the precursor through an ultrasonic diagnosis method. However, it is difficult to perform a degradation mechanism analysis since measuring the viscosity and physical properties of TDMAT is complicated due to its sensitivity to air. Therefore, viscosity was measured using a Pd compound (tetrakis(triphenylphosphine)palladium(0), Pd(PPh3)4) which is stable in air and has a similar chemical structure to TDMAT.