FTIR and ellipsometry characterization of ultra-thin ALD TaN films

TY - JOUR

T1 - FTIR and ellipsometry characterization of ultra-thin ALD TaN films

AU - Wu, Y. Y.

AU - Eizenberg, M.

N1 - Funding Information: This work was supported by the “Magnet” program of the Chief Scientist Office at the Israel Ministry of Industry and Trade, Consortium of Emerging Dielectric and Conductor Technologies for the Semiconductor Industry. Y.Y. Wu acknowledges the support of the Lady Davis Fellowship Trust. The authors thank Applied Materials Inc., Santa Clara, for preparing the wafer samples.

PY - 2007/2/15

Y1 - 2007/2/15

N2 - In this paper, Fourier-transform infrared (FTIR) spectroscopy and ellipsometric spectroscopy were used to characterize the optical properties of atomic layer-deposited (ALD) ultra-thin TaN films on a Si(1 0 0) single crystal. The analysis of FTIR spectra indicates that the incorporated impurities are in the form of radicals of NHx, CHx and OHx. SiHx is also detected due to interfacial reactions between NHx and the Si substrate native oxide. These H-containing radicals can be removed by post-annealing the samples. The vibration of Ta-N bonding is at the wavenumber of 1190 cm-1, which is independent of the film thickness and post-annealing temperature. The results of ellipsometric spectra show that the band gaps are 3.28 eV, 2.65 eV and 2.50 eV as the films thicknesses are 1 nm, 5 nm and 10 nm, respectively. A slight red-shift of the band gap takes place after annealing the ultra-thin films. The mechanisms of the film optical properties were analyzed in the paper.

AB - In this paper, Fourier-transform infrared (FTIR) spectroscopy and ellipsometric spectroscopy were used to characterize the optical properties of atomic layer-deposited (ALD) ultra-thin TaN films on a Si(1 0 0) single crystal. The analysis of FTIR spectra indicates that the incorporated impurities are in the form of radicals of NHx, CHx and OHx. SiHx is also detected due to interfacial reactions between NHx and the Si substrate native oxide. These H-containing radicals can be removed by post-annealing the samples. The vibration of Ta-N bonding is at the wavenumber of 1190 cm-1, which is independent of the film thickness and post-annealing temperature. The results of ellipsometric spectra show that the band gaps are 3.28 eV, 2.65 eV and 2.50 eV as the films thicknesses are 1 nm, 5 nm and 10 nm, respectively. A slight red-shift of the band gap takes place after annealing the ultra-thin films. The mechanisms of the film optical properties were analyzed in the paper.

KW - Atomic layer deposition

KW - Ellipsometry

KW - FTIR

KW - Tantalum nitride

UR - http://www.scopus.com/inward/record.url?scp=33846409475&partnerID=8YFLogxK

U2 - 10.1016/j.matchemphys.2006.05.002

DO - 10.1016/j.matchemphys.2006.05.002

M3 - 文章

AN - SCOPUS:33846409475

SN - 0254-0584

VL - 101

SP - 269

EP - 275

JO - Materials Chemistry and Physics

JF - Materials Chemistry and Physics

IS - 2-3

ER -