Atomic-Scale Desorption Through Electronic and Vibrational Excitation Mechanisms

• DOI: 10.1126/science.268.5217.1590
• Publication Date: 2006-10-27T18:19:42Z
• Authors: T. -C. Shen; C. Wang; G. C. Abeln; J. R. Tucker; J. W. Lyding; Ph. Avouris; R. E. Walkup
• Keywords: atomic; electronic; Physics; vibrational; desorption; excitation; 02 engineering and technology; 0210 nano-technology

The scanning tunneling microscope has been used to desorb hydrogen from hydrogen-terminated silicon (100) surfaces. As a result of control of the dose of incident electrons, a countable number of desorption sites can be created and the yield and cross section are thereby obtained. Two distinct desorption mechanisms are observed: (i) direct electronic excitation of the Si-H bond by field-emitted electrons and (ii) an atomic resolution mechanism that involves multiple-vibrational excitation by tunneling electrons at low applied voltages. This vibrational heating effect offers significant potential for controlling surface reactions involving adsorbed individual atoms and molecules.