Temperature dependence of atomic scale manipulation of hydrogen on Si(001) surfaces

The temperature dependence of scanning tunneling microscopy induced extraction and deposition of hydrogen atoms on Si(001) 2x1 and 3x1 hydrogen passivated surfaces is analyzed. Deposition of hydrogen onto the Si surfaces is only observed at negative sample bias voltage, whilst extraction can be obtained at both polarities of bias. Increasing the sample temperature at negative bias increases the tunnel current required for extraction of hydrogen considerably, but this effect is small for positive bias. A larger current is required for extraction of hydrogen from 3x1 surfaces than from 2x1 surfaces. A phase change from the 2x1 structure to the 3x1 structure induced by the scanning tunneling microscope is also reported.