Photo-electrochemical etching of macroporous silicon arrays used in silicon microchannel plates

The current-voltage curve of an n-type silicon wafer was presented in aqueous HF. The critical current density J_PS was discussed. The control technology of channel dimension was studied and realized by changing the etching current density according to the J_PS and dark current density. The pore morphology influenced by the working voltage were studied and analyzed. The dependence of macropore morphology on the orientation of n-type silicon was studied. The tilt channels array with smooth pore wall can be prepared by adopting the <;118>; orientation silicon wafer, and can satisfy the demand of microchannel plates for tilt angles of 7-15 degrees. A macroporous silicon arrays with the very high aspect ratio was prepared by the photo-electrochemical etching process.