Recent advancement in microgap electrode fabrication by conventional photolithography technique

The biosensors which based on polysilicon material should be sensitive and selective for the detection of label free bio molecule. The objective of this research is to characterize, design, and fabricate polysilicon nanogap. The proposed device was designed initially in two masks by using AutoCAD software and then transferred to commercial chrome mask. The standard CMOS photolithography process coupled with ICP dry etching process is used for fabrication of the proposed nanogap. The fabrication process start by microgap formation and than by size expansion technique the microgap expand to nanogap and finally gold pad were deposited on polysilicon nanogap surface. Using TEM, FIB, FESEM and AFM the nanogap was inspected and characterized. At last the surface modification of polysilicon nanogap and DNA immobilization is done on polysilicon nanogap for the testing and validation by using real biological samples. The initial study demonstrates the fabrication of microgap of 1, 2, 3μm and 40.7, 43.5, 115.2, 335.9μm on polysilicon wafer samples.