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

摘要

The temperature dependence of hydrogen (H) desorption from Si(100)H-terminated surfaces by a scanning tunneling microscope (STM) is reported fornegative sample bias. It is found that the STM induced H desorption rate ($R$)decreases several orders of magnitude when the substrate temperature isincreased from 300 K to 610 K. This is most noticeable at a bias voltage of -7V where $R$ decreases by a factor of ~200 for a temperature change of 80 K,whilst it only decreases by a factor of ~3 at -5 V upon the same temperaturechange. The experimental data can be explained by desorption due to vibrationalheating by inelastic scattering via a hole resonance. This theory predicts aweak suppression of desorption with increasing temperature due to a decreasingvibrational lifetime, and a strong bias dependent suppression due to atemperature dependent lifetime of the hole resonance.