STM tip-induced creation and annihilation of small Ge clusters and missing dimer vacancies on Ge(001)

We have observed the appearance and disappearance of small Ge clusters and missing dimer vacancies on Ge/(011) during scanning with a scanning tunneling microscope (STM) under standard tunneling conditions at room temperature. We claim that these processes are induced by the STM tip. Moreover, we emphasize that the observed features depend on the usage of different W tips, even if prepared following the same procedure and using the same tunneling conditions, suggesting a critical influence of the tip shape.