Effect of the Gas‐Phase Reaction in Metallorganic Chemical Vapor Deposition of TIN from Tetrakis(dimethylamido)titanium

Abstract

The effect of the gas-phase reaction on the deposition rate and the properties of TiN films from metallorganic chemical vapor deposition with tetrakis(dimethylamido)titanium was investigated. In situ Fourier transform infrared spectrometry was used to study the gas-phase reaction mechanism, and the deposition of TiN films was carried out in a low pressure, cold-wall chemical vapor deposition reactor at a deposition temperature from 200 to 400°C. It was observed that tetrakis(dimethylamido)titanium in the gas phase was dissociated into dimethylamine above 280°C, and, in this case, the deposition rate was decreased and a Ti-rich film was formed. It was shown that the gas-phase reaction has a significant effect not only on the deposition rate but also on the film properties.

Nondispersive Infrared Gas Analyzer for Partial Pressure Measurements of a Tantalum Alkylamide During Vapor Deposition Processes

“…While this NDIR gas analyzer was specifically tested for PDMAT and DMA, it is suitable for characterizing the vapor delivery of other metal dimethylamido compounds that exhibit an absorption feature corresponding to the filter center wavelength of 10.56 μm (≈947 cm −1 ), e.g., tetrakis(dimethylamido) titanium (TDMAT) with a feature in the ≈943 cm −1 to ≈950 cm −1 range, 15–18,27,33,37–41 tetrakis(dimethylamido) hafnium with a feature in the ≈942 cm −1 to ≈943 cm −1 range, 27,42 tetrakis(dimethylamido) vanadium with a feature reported at 944 cm −1 , 27 pentakis(dimethylamido) niobium with a feature reported at 938 cm −1 , 27 and tetrakis(dimethylamido) zirconium with a feature in the ≈933 cm −1 to ≈936 cm −1 range, 27,43 although the NDIR analyzer performance would presumably degrade as the peak absorbance deviated from the filter center wavelength. The DMA 14.03 μm center wavelength filter is also suitable for monitoring the amines corresponding to the hydrogenated ligands of metal ethylmethylamide and metal diethylamide compounds: the N–H bending mode in methylethylamine is observed in the ≈724 cm −1 to ≈725 cm −1 range, 31,44 while that of diethylamine is observed in the ≈716 cm −1 to ≈721 cm −1 range.…”

“…However, metal alkylamide compounds can pyrolyze at elevated temperatures to produce the secondary amine corresponding to the hydrogenated ligand of the parent molecule. [14][15][16][17][18] In the case of PDMAT, the amine is dimethylamine (DMA), (CH 3 ) 2 NH. The presence of the amine can potentially impact deposition processes via (1) perturbation of the metal alkylamide flux through perturbations of the system pressure and (2) inhibition of reactions in which DMA is a product, e.g., transamination reactions with ammonia.…”

Quantitative Infrared Spectroscopy of Tetrakis(dimethylamido)Titanium for Process Measurements

“…Integrated absorptivity (cm −1 ) ( × 10 4 m/mol) is found in Ref. 10 where spectra obtained from TDMAT flowing through a cell at 600 K exhibit peaks at 2777 cm −1 that are greater than the other C-H stretch modes. This indicates the gas was cooler than the cell.…”

Improvement of Heater Surface Flatness and Uniformity of TiN Film Deposition

“…[2,3,8,9] Another approach is low-temperature MOCVD with metal-organic compounds such as tetrakis-dimethyl-amido-titanium and tetrakis-diethyl-amidotitanium. [2,[7][8][9][10][11] The TiN-CVD process is a thermal process. The deposition rate is sensitive to the wafer temperature, and heat energy is transferred to the wafer from the heater surface.…”