Thermal Decomposition In Situ Monitoring System of the Gas Phase Cyclopentadienyl Tris(dimethylamino) Zirconium (CpZr(NMe2)3) Based on FT-IR and QMS for Atomic Layer Deposition

Abstract

We developed a newly designed system based on in situ monitoring with Fourier transform infrared (FT-IR) spectroscopy and quadrupole mass spectrometry (QMS) for understanding decomposition mechanism and byproducts of vaporized Cyclopentadienyl Tris(dimethylamino) Zirconium (CpZr(NMe 2) 3) during the move to process chamber at various temperatures because thermal decomposition products of unwanted precursors can affect process reliability. The FT-IR data show that the-CH 3 peak intensity decreases while the-CH 2and C=N peak intensities increase as the temperature is increased from 100 to 250°C. This result is attributed to decomposition of the dimethylamido ligands. Based on the FT-IR data, it can also be assumed that a new decomposition product is formation at 250°C. While in situ QMS analysis demonstrates that vaporized CpZr(NMe 2) 3 decomposes to Nethylmethanimine rather than methylmethyleneimine. The in situ monitoring with FT-IR spectroscopy and QMS provides useful information for understanding the behavior and decomposes of CpZr(NMe 2) 3 in the gas phase, which was not proven before. The study to understand the decomposition of vaporized precursor is the first attempt and can be provided as useful information for improving the reliability of a high-advanced ultra-thin film deposition process using atomic layer deposition in the future.

On the Use of Carbon Cables from Plastic Solvent Combinations of Polystyrene and Toluene in Carbon Nanotube Synthesis

“…Carbon from the cyclopentadienyl could also contribute to the carbon of the CNT [53]. Cyclopentadiene moieties, sandwiching iron in the case of ferrocene, tend to exhibit relatively high thermal stability on account of the strong binding affinity between those groups and the internal metal atoms [54]. Therefore, complete decomposition of the ferrocene complex was only expected to occur in zone two, where the temperature for growth was set at 780 • C. First, the cyclopentadienyls disassociated from the iron core and underwent further decomposition in the presence of the newly formed catalysts nanoparticles.…”

Role of Cyclopentadienyl Ligands of Group 4 Precursors toward High-Temperature Atomic Layer Deposition

“…In the case of precursors containing the amido ligands (−NR 2 ), the molecular stability against thermal decomposition is established by the reaction between the ligands. ,, Accordingly, several different pathways for the interaction between the amido ligands of the exemplary TDMAT precursor were analyzed as follows (Figure S2). Ti ( N M e 2 ) 4 → Ti false( normal M e N= CH 2 false) ( N normal M e 2 ) 2 + HN M e 2 Ti ( N M e 2 ) 4 → HTi ( normal N normal M e 2 ) 3 + M e N= C H 2 Ti ( N M e 2 ) 4 → Ti false(…”

“…In the case of precursors containing the amido ligands (−NR 2 ), the molecular stability against thermal decomposition is established by the reaction between the ligands. ,, Accordingly, several different pathways for the interaction between the amido ligands of the exemplary TDMAT precursor were analyzed as follows (Figure S2). …”

“…These precursors, however, sometimes have drawbacks such as halide contamination and low stabilities in the case of the halide and alkoxides, respectively. Consequently, heteroleptic precursors including more than one type of ligands such as cyclopentadienyl (Cp)-alkoxides and Cp-alkylamides are developed, to enhance the thermal stability of precursors of the ALD high-k oxides. − When ozone is used as the oxygen source, ALD using zirconium and hafnium Cp-alkylamide precursors shows high growth per cycle (GPC), ranging from 0.8 to 0.9 Å per cycle, and the deposited films mostly possessed low levels of nitrogen and carbon contamination. Especially, ZrO 2 and HfO 2 films deposited using CpZr­(N­(Me 2 ) 3 and CpHf­(N­(Me 2 ) 3 precursors (Me = CH 3 ) and ozone have shown improved film density and electrical performance, possibly due to the deposition temperatures being as high as 350 °C.…”