AVS 49th International Symposium
    Electronic Materials and Devices Wednesday Sessions
       Session EL+SS+SC-WeA

Paper EL+SS+SC-WeA5
Surface Reaction Study of Tungsten Nitride Precursors Decomposition on Si(100)-(2 x 1)

Wednesday, November 6, 2002, 3:20 pm, Room C-107

Session: Semiconductor Film Growth and Oxidation
Presenter: Y.-W. Yang, Synchrotron Radiation Research Center, Taiwan
Authors: Y.-W. Yang, Synchrotron Radiation Research Center, Taiwan
J.-B. Wu, National Chiao-Tung University, Taiwan
Y.-F. Lin, National Chiao-Tung University, Taiwan
H.-T. Chiu, National Chiao-Tung University, Taiwan
Correspondent: Click to Email
Reaching an atomic-scale understanding of the surface reaction pathways followed by precursors during MOCVD thin-film growth is a daunting task. We have been studying the transition metal nitride growth on both Cu and Si surfaces. Here, we report a thermal decomposition study of WN precursor on Si(100)-(2 x 1) using TDS and synchrotron-based XPS techniques. The studied precursors are (t-BuN)@sub 2@W(NHBu-t)@sub 2@ and (t-BuN)@sub 2@W(NEt@sub 2@)@sub 2@ and their structural characteristics consist of the presence of both W-N and W=N bonds and either the presence or the absence of @beta@-H that influences the thermolysis of the precursors. XPS data show that the metallic tungsten already forms for a submonolayer dose of the precursors at room temperature, suggesting the complete abstraction of the amine ligands by the dangling bonds on Si(100) surface. The evolution of hydrocarbon and amine species during the pyrolysis are followed by the TDS and the results suggests the similarity to the amine adsorption on Si(100). High temperature annealing produces silicon carbides and silicon nitrides. In stark contrast, no metallic tungsten is ever formed during the pyrolysis of the same precursors on Cu(111) and the formation of tungsten nitride is secured through the gradual loss of excessive amine ligands. Based on these results, possible surface reaction mechanism and the structural effect of the precursor are to be discussed.