AVS 47th International Symposium
    Semiconductors Tuesday Sessions
       Session SC+EL+SS-TuM

Invited Paper SC+EL+SS-TuM7
Role of Ligand Termination in Atomic-Layer-Controlled Growth

Tuesday, October 3, 2000, 10:20 am, Room 306

Session: Compound Semiconductors
Presenter: R.M. Osgood, Columbia University
Authors: R.M. Osgood, Columbia University
N. Camillone III, Columbia University
Y. Luo, Columbia University
M. Han, Columbia University
Correspondent: Click to Email
We describe employment of a series of in situ UHV diagnostics to study the surface chemistry of ligand capping in limiting reactions for atomic-layer-defined growth of semiconductor thin films. In the study, molecular precursors were on surfaces held at temperatures from 180-300K in a UHV chamber. The terminating groups, formed by the dosing, were identified and their chemistry investigated using thermal desorption spectroscopy, NEXAFS, Auger, spectroscopy, and LEED. Using CdS growth on ZnSe(100) as the model system, we have found that CH@sub 3@ and H terminal groups deposited by reactions with Cd(CH@sub 3@)@sub 2@ and H@sub 2@ S, respectively, effectively limit growth precisely on all except the first monolayer. A study of intermixing in the first layer shows clearly the role of surface temperature in controlling the reaction chemistry and coverage of terminating species. The implications with regard to atomic-layer-controlled growth of other systems will also be discussed.