Study Of Transport Properties Of Holes In Process Of Electrochemical Etching Silicon Microchannels

The research on silicon microchannel arrays has achieved significant progress and the application fields of high aspect ratio Si microchannel arrays have increased considerably, but the transport characteristics of current carriers in silicon wafer in electrochemical etching silicon microchannel arrays are rarely reported. But hole excitation and transportation have direct effect on the etching results of silicon microchannel arraysIn this paper, based on the basic properties of silicon and the band theory of silicon, the principle of transport mechanism of hole in process of etching silicon microchannel arrays is expounded; with the n-type silicon wafer as the research subject, the characteristic curves of current-voltage for silicon wafers which phosphorus diffusion and ion implantation are applied in silicon wafers; designs the experiments with different conditions of light intensity and wavelength, and finds out the best excitation wavelength for silicon wafer is850nm; designs the experiments with different conditions of temperature and etching voltage, the characteristic curves of current-voltage for silicon microchannel arrays are analyzed and the surface morphologies of silicon microchannel arrays are contrasted by metallographic microscope. The relationship among temperature, etching voltage and carrier transportation was presented by the mechanisms of impurity scattering and lattice scattering. The best etching condition:light source is LED array (infrared light of850nm wavelength), etching voltage is0.6V～0.5V, etching temperature is13℃, etching time is10hours.