Laser etching on the Cl-saturated Si(111)7*7 surface at 266 nm studied by scanning tunnelling microscopy

Using scanning tunnelling microscopy, the authors have observed structural modifications of the chlorinated Si(111)7*7 surface induced by 266 nm laser irradiation. At a very low laser fluence of 0.7 mJ cm-2, at which thermal desorption can be ignored, a periodic striped pattern along the (110) direction of the Si(111) surface is imaged. This pattern consists of flat terraces and narrow grooves of approximately 60 and approximately 10 AA in width, respectively.