SCANNING TUNNELING SPECTROSCOPY

The development of the field of spectroscopic measurement with the sca nning tunneling microscope (STM) is discussed. A historical review of early experimental results in this field is presented, with emphasis o n the techniques for data acquisition and interpretation. The applicab ility of STM spectroscopic measurement to surface structural determina tion is addressed. The role of geometric versus electronic contributio ns to STM images is discussed, with reference to studies of Si(111)7 x 7, Si(111)2 x 1, and Ge(111)c(2 x 8) surfaces. It is concluded that, for semiconductor surfaces, the observed corrugations are dominated by electronic effects. Issues of dynamic range in spectroscopic measurem ent, and interpretation of spectroscopic images, are examined.