Measurements of Metal Alkylamide Density During Atomic Layer Deposition Using a Mid-Infrared Light Emitting Diode Source
James E. Maslar, John J. Hoang, William A. Kimes, Brent A. Sperling
non-dispersive infrared gas analyzer for monitoring the metal alkylamide compound tetrakis(dimethylamido) titanium (TDMAT) that utilizes a mid-infrared light emitting diode source was demonstrated. The sensitivity of this technique to TDMAT was determined by comparing the absorbance measured using this technique to the TDMAT density as determined using in situ Fourier transform infrared spectroscopy. A minimum detectable TDMAT density as low as 4 x 1014 molecules/cm3 was demonstrated. The sensitivity of this technique to dimethylamine (DMA), a common deposition product with the potential to interfere with TDMAT detection, was determined by measuring DMA absorbance as a function of pressure. The ratio of the TDMAT sensitivity to the DMA sensitivity was about 6. During atomic layer deposition of titanium dioxide using TDMAT and water, it was found that the interfering effects of the evolution of DMA and deposition of species on the windows corresponded to a maximum of only about 6 % of the total observed TDMAT density.
, Hoang, J.
, Kimes, W.
and Sperling, B.
Measurements of Metal Alkylamide Density During Atomic Layer Deposition Using a Mid-Infrared Light Emitting Diode Source, Applied Spectroscopy, [online], https://doi.org/10.1366/14-07695
(Accessed December 5, 2023)