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

The temperature dependence of hydrogen (H) desorption from Si(100) H-termin ated surfaces by a scanning tunneling microscope (STM) is reported for nega tive sample bias. It is found that the STM induced H desorption rate (R) de creases several orders of magnitude when the substrate temperature is incre ased from 300 to 610 K. This is most noticeable at a bias voltage of -7 V w here R decreases by a factor of 200 for a temperature change of 80 K, whils t it only decreases by a factor of 3 of at -5 V upon the same temperature c han ge. The experimental data can be explained by desorption due to vibrati onal heating by inelastic scattering via a hole resonance. This theory pred icts a weak suppression of desorption with increasing temperature due to a decreasing vibrational lifetime, and a strong bias dependent suppression du e to a temperature dependent lifetime of the hole resonance. (C) 1999 Elsev ier Science B.V. All rights reserved.