Large Size P-type Silicon Microchannel Plates Prepared By Photo-Electrochemical Etching

The process of the fabrication of large and high aspect ratio silicon microchannels plates by the photo-electrochemical process is described. The influence of backside illumination and temperature on the process is also concerned. Backside illumination is provided by three 150W tungsten halogen lamps with a feedback loop keeping a constant current density. The etching temperature is maintained by a circulation system. Proper backside illumination and the lower temperature can provide better integrated etching conditions compared to that without illumination and temperature control. Etching under the improved conditions results in smoother undercutting and better surface topography for large (effective diameter of about 80 mm for 4-inch silicon substrates) silicon microchannel plates. Enhancing the backside illumination within the etching temperature range ensures the aspect ratio to be more than 40 boding well for applications of the silicon microchannel plates.Chapter 1 introduces the primary applications of micro channel structure, fabrication methods of silicon micro channel started with MEMS(Micro-Electro-Mechanical Systems), and the properties.Chapter 2 introuduces the theory of the photo electrochemical (PEC) etching and the basic processes flow of fabricating high area ratio silicon microchannels.In Chapter 3 the mechanism and influence of the PEC etching process for P type silicon micro channel is studied.In Chapter 4 the analysis after the scaling-up of the process is discussed.Chapter 5 is the summarizing of this thesis and the prospect of silicon micro channel application in the future.