AVS 45th International Symposium
    Surface Science Division Monday Sessions
       Session SS-MoP

Paper SS-MoP21
Electron Induced Reactions of Ammonia and Nitric Oxide Adsorbed on Si(100)

Monday, November 2, 1998, 5:30 pm, Room Hall A

Session: Surface Science Division Poster Session
Presenter: C. Bater, University of Texas, El Paso
Authors: C. Bater, University of Texas, El Paso
J.H. Craig, University of Texas, El Paso
J.H. Campbell, University of Texas, El Paso
Correspondent: Click to Email
Electron beam enhanced nitridation of Si(100) by ammonia and nitric oxide was studied using XPS, TPD, ESD and HREELS. At low coverages, both ammonia and nitric oxide dissociatively adsorbed on Si(100) at 120 K while molecularly adsorbed ammonia and nitric oxide were detected by TPD and HREELS at higher exposures. Ammonia condenses on the surface at 110 K. During electron beam irradiation, adsorbed hydrogen atoms were effectively removed from the surface so that the site poisoning effect of adsorbed hydrogen was reduced. The electron stimulated dissociation of the adsorbed NH@sub x@ species enhanced the nitridation process. Enhanced nitride formation occurred when weakly physisorbed and condensed ammonia were present on Si(100) during electron beam irradiation at 110 K. H@super +@ ESD KEDs were used to deduce the surface reaction occurring during electron beam irradiation, and HREELS following electron beam irradiation was used to confirm and enhance the conclusions drawn from the ESD study. The formation of nitride and oxynitride was observed using the peak shifts of the N 1s and Si 2p X-ray photoelectron peaks. From the O@super +@ ESD KED signals, we distinguished O@super +@ originating from NO(a) and O(a), which we used to monitor the surface reaction occurring during electron beam irradiation. Changes in surface chemistry due to different levels of surface nitridation were also studied extensively. From the H@super +@ and O@super +@ ESD decay curves, the ESD cross sections for different surface conditions were obtained.