TY  - JOUR
PY  - 2004//
TI  - Characterization of Atomic Layer Deposited WNxCy Thin Film as a Diffusion Barrier for Copper Metallization
JO  - Journal of the Electrochemical Society
A1  - Kim, S.-h.
A1  - Oh, S.S.
A1  - Kim, H.-m.
A1  - Kang, D.-h.
A1  - Kim, K.-b.
A1  - Li, W.-m.
A1  - Haukka, S.
A1  - Tuominen, M.
SP  - C272
EP  - C282
VL  - 151
IS  - 4
N2  - The properties of WNxCy, films deposited by atomic layer deposition (ALD) using WF6, NH3, and triethyl boron were characterized as diffusion barriers for copper metallization. The films deposited at 313°C showed resistivity of about 350 μΩ cm with a density of 15.4 g/cm3. The film composition measured by Rutherford backscattering spectrometry showed W, C, and N of approximately 48, 32, and 20 atom %, respectively. Transmission electron microscopy analyses showed that the as-deposited film was composed of a face-centered-cubic phase with a lattice parameter similar to both β-WC1-x and β-W2N with an equiaxed microstructure. The film kept its nanocrystalline microstructure until annealing at 700°C, although some amount of simple hexagonal α-WC was identified to be formed and the β-W2N phase disappeared. As the annealing temperature increased to 800°C, relatively larger grains of body-centered-cubic W were newly formed with smaller grains of hexagonal-close-packed α-W2C or α-WC. All the phenomena are related to nitrogen release after annealing at 700 and 800°C. The results of diffusion barrier performance between Cu and Si analyzed by X-ray diffractometry showed that ALD-WNxCy film (12 nm) failed only after annealing at 700°C for 30 min by the formation of copper suicide, while the sputter-deposited Ta (12 nm) and ALD-TiN (20 nm) films failed at 650 and 600°C annealing, respectively. It is thought that the superior diffusion barrier performance of ALD-WNxCy, film is the consequence of both the formation of equiaxed microstructure and the high-density nature of the film. © 2004 The Electrochemical Society.<p /> <p>Language: en</p>
LA  - en
SN  - 0013-4651
UR  - http://dx.doi.org/10.1149/1.1652054
ID  - ref1
ER  -