Study On The Application Of Silica-based Orderly Porous Silicon In Biosensor

Porous silicon based on silicon substrate is a new type material used as sensing platforms.PSi has unique properties including large surface-to-volume ratio,tunable pore structure,high chemical activity of surface and the simple fabrication method,and easily compatible with the fabrication techniques of microelectronics.So it received great attention from a large number of researchers.A variety of pore morphologies can be obtained by adjusting the parameters of the fabrication process,including the electrolyte composition,etching current density,and etching time.The optical interference properties of PSi can be accurately controlled by adjusting and modulating the geometric orientation,pore size,and the thickness of the porous silicon layer.In this work,we obtained the orderly nanometer porous silicon in n-type orientation silicon wafer by using electrochemical etching.The influence of the corrosion solution composition,current density,and corrosion time for porous silicon microstructure was investigated.We get some solution to remove the tiny pore in porous silicon surface.The optical property based on Fabry-Perot effect of nanometer porous silicon was also investigated.The work of this paper is as follows:(1)The mesoporous porous silicon and macroporous porous silicon had been prepared with ethanol and isopropanol as solvent corrosion fluid,respectively,The influence of applied current density and etching time for porous silicon microstructure was studied.With the increasing of current density,pore diameter,porosity of porous silicon and the layer thickness were increased.The layer thickness of porous silicon was increased when increasing the etching time.(2)The porous silicon displayed good interference effect as the layer thickness less than 10 ?m.The sample show higher sensitivity for ethanol solution when porosity larger than 75%.(3)The solution was also been studied in order to remove the tiny pore in the porous silicon surface.The surface chemical state changes of porous silicon under different temperatures by rapid heat treatment system were investigated.