LOCAL MODIFICATION OF HF-TREATED SILICON (100) SURFACE AND ITS CHARACTERIZATION BY SCANNING-TUNNELING-MICROSCOPY AND SPECTROSCOPY

The modification of silicon (100) surfaces on samples etched with HF and without rinsing in de-ionized H2O is produced and studied by scanning tunneling microscopy and spectroscopy. The dependence of the size of the modification with the tunnel current and the voltage between tip and sample is explained from the evaluation of the electrical field between the tip and the silicon surface, starting from the planar metal-insulator-semiconductor theory. Current image tunneling spectroscopy data allow to clarify the nature of the modification, concluding that an electrochemical change on the surface of the sample has been produced.