IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Dielectrics Wednesday Sessions
       Session DI-WeM

Paper DI-WeM4
Nucleation and Growth Chemistry during Tungsten Atomic Layer Deposition on Oxide Surfaces

Wednesday, October 31, 2001, 9:20 am, Room 130

Session: Atomic Layer Deposition for Silicon Devices
Presenter: R.K. Grubbs, University of Colorado, Boulder
Correspondent: Click to Email
The nucleation and growth chemistry during tungsten (W) atomic layer deposition (ALD) on SiO@sub 2@ and Al@sub 2@O@sub 3@ surfaces were studied using Auger electron spectroscopy and quadrupole mass spectrometry. W ALD was performed using sequential exposures of WF@sub 6@ and Si@sub 2@H@sub 6@. Differences in the nucleation process and the film growth mode were observed for the two oxide substrates. The nucleation of W ALD on SiO@sub 2@ required 8-9 WF@sub 6@/Si@sub 2@H@sub 6@ reaction cycles. A much shorter nucleation period was observed on Al@sub 2@O@sub 3@. W ALD on SiO@sub 2@ followed a Frank-Van der Merwe, layer-by-layer, growth mode while W ALD on Al@sub 2@O@sub 3@ occurred with a Volmer-Weber growth mode. These results indicate that the identity of the underlying substrate has an affect on the nucleation and growth of W ALD films. The growth chemistry of W ALD was studied using quadrupole mass spectrometry. The reaction products from each sequential reaction were identified and correlated with the Auger results. The reaction products suggest the stoichiometry of the surface reactions during tungsten atomic layer deposition.