Development of microstructure on polysilicon substrate by reactive ion etching (RIE) for future reproductivity of nanogap

This article is a study about dry etching as applied to etch substrate directionality, which is the important feature of RIE. The biosensors based on polysilicon material should be sensitive and selective for the detection of bio molecule. The objective of this research is to design, and fabricate polysilicon microstructure. The proposed microstructure was designed initially by using AutoCAD software and then transferred to commercial chrome mask. Standard CMOS photolithography process coupled with RIE dry etching is used for fabrication of proposed microstructure. The fabrication process start by microstructure formation on resist and than by reactive ion etching (RIE) the proposed polysilicon microstructure was created onto samples wafer. Future work will focuse to reduce the microstructure width and finally break the microstructure to create nanogap by size reduction technique using thermal oxidation. For biomolecules sensing applications, the size of the gap must be small enough to allow the biomolecule inserted into the gap space to connect both leads to keep the molecules in a relaxed and undistorted state.