Modelling of the electrochemical stage of process of formation the probes of STM

In this paper questions are considered of modeling of an electrochemical stage of reproduction the probes for the scanning tunnel microscope by method of the combined etching. An etching of tungsten blank of probe is carried out in the thin film of electrolyte which is formed in case of alkali solution current through a plate with the cut-out opening and channels for inflow and a drain of the etching liquid. Electrochemical etching allows a high speed production a necessary macroscopic shape of the probe edge, so-called probe "neck", for the subsequent stage of chemical etching. The model of a stage of electrochemical etching relies on the processes described by the equations of mathematical physics. At the same time hydrodynamic, thermal and diffusive processes, and also distribution of potential of the electric field providing the electrochemical reaction at the probe blank are considered. These effects are researched by inclusion in system of the equations of Navier-Stokes, heat cunduction, a mass transfer and Laplace. In work images of blanks of STM-probes at various stages of electrochemical etching are provided. It is shown that parameters of electrochemical reaction significantly influence the "neck" shape of the blank of STM-probes. It is revealed that the macroscopic "neck" shape of the probe blank is completely determined by boundary and entry conditions of reaction. Influence of each factor is individual, and their joint change is capable to vary dynamics of process of electrochemical etching for receipt of a necessary macroscopic shape of an edge.