Temperature suppression of STM-induced desorption of hydrogen on Si(100) surfaces

SURFACE SCIENCE

卷:424

Letter

Thirstrup, C ; Sakurai, M ; Nakayama, T ; Stokbro, K

关键词: ab initio quantum chemical methods and calculations;    electron stimulated desorption;    hydrogen;    low index single crystal surfaces;    scanning tunneling microscopy;    silicon;    vibrations of adsorbed molecules;   

DOI  :  10.1016/S0039-6028(99)00202-2

来源: Elsevier

【 摘 要 】

The temperature dependence of hydrogen (H) desorption from Si(100) H-terminated surfaces by a scanning tunneling microscope (STM) is reported for negative sample bias. It is found that the STM induced H desorption rate (R) decreases several orders of magnitude when the substrate temperature is increased from 300 to 610 K. This is most noticeable at a bias voltage of -7 V where R decreases by a factor of 200 for a temperature change of 80 K, whilst it only decreases by a factor of 3 of at -5 V upon the same temperature chan ge. The experimental data can be explained by desorption due to vibrational heating by inelastic scattering via a hole resonance. This theory predicts a weak suppression of desorption with increasing temperature due to a decreasing vibrational lifetime, and a strong bias dependent suppression due to a temperature dependent lifetime of the hole resonance. (C) 1999 Elsevier Science B.V. All rights reserved.

【 授权许可】

Free