IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Applied Surface Analysis Monday Sessions
       Session AS-MoP

Paper AS-MoP9
Experimental vs. Theoretical Studies of Amine Reaction Pathways on Si(100)

Monday, October 29, 2001, 5:30 pm, Room 134/135

Session: Student Poster Competition/Aspects of Applied Surface Analysis I Poster Session
Presenter: A.J. Carman, University of Nevada, Reno
Authors: A.J. Carman, University of Nevada, Reno
S.M. Casey, University of Nevada, Reno
Correspondent: Click to Email
Theoretical analysis of methylamine (MA) and dimethylamine (DMA) adsorption on silicon clusters has been undertaken to deduce the mechanism by which small carbon- and nitrogen-containing molecules react with the silicon surface. Possible dissociative adsorption pathways have been examined including calculating transition states from the physisorbed state to the dissociated, chemisorbed products. Three reaction pathways were examined: N-H bond cleavage, N-C bond cleavage, and C-H bond cleavage, followed by adsorption of the resulting fragments. The N-H bond cleavage pathway presents the lowest transition state to dissociative adsorption for both molecules. MA adsorption on the Si(100)-(2x1) surface has also been studied experimentally using Auger electron spectroscopy (AES), low-energy electron diffraction, and thermal desorption spectroscopy (TDS). Experimental evidence shows that at room temperature MA chemisorbs dissociatively on this surface. TDS data show that the chemisorbed adsorbates can decompose via reactions that form gaseous hydrogen, ammonia, and methylimine products. AES results show that MA surface decomposition leads to the slow deposition of carbon- and nitrogen-based films. An analysis of the AES and TDS data will be discussed along with results from the theoretical adsorption studies to examine the predictive power of these computational methods.