Polysilicon nanogap structure development using size expansion technique

Abstract

Purpose -Nanobiosensors based on nanogap capacitor are widely used for measuring dielectric properties of DNA, protein and biomolecule. The purpose of this paper is to report on the fabrication and characterization polysilicon nanogap patterning using novelties technique. Design/methodology/approach -Overall, the polysilicon nanogap pattern was fabricated based on conventional lithographic techniques. For size expansion technique, by employing simple dry thermal oxidation, the couple of nanogap pattern has been expanded to lowest nanogap value. The progress of nanogap pattern expansion was verified by using scanning electron microscopy (SEM). Conductivity, resistivity, and capacitance test were performed to characterize and to measure electrical behavior of full device fabrication. Findings -SEM characterization emphasis on the expansion of polysilicon nanogap pattern increasing with respect to oxidation time. Electrical characterization shows that nanogap enhanced the sensitivity of the device at the value of nano ampere of current. Originality/value -These simple least-cost method does not require complicated nanolithography method of fabrication but still possible to serve as biomolecular junction. This approach can be applied extensively to different design of nanogap structure down to several nanometer levels of dimensions. A method of preparing a nanogap electrode according to the present innovation has an advantage of providing active surface that can be easily modified for immobilizations of biomolecules.

In-House fabrication and Electrical characterization of planner si-nanogap

“…Due to the inherent capability of electrical detection methods in allowing Interaction with the targeted ssDNA to create a field across the transducer and increase the capacitive effect, the nanogap capacitor is special kind of capacitor that based on electrical double layer (EDL) theory that has been recognised by chemist since the nineteenth century when Von Helmholtz first developed and modelled his colloidal suspension work [5]. Previous designs of planar nanogap are still lack in geometry and structure [6][7]. Yexian Wu and co-worker using ebeam to fabricate heterogeneous metal nanogaps but still the contact surface area is not well defined [8] The geometry of the nanogap electrode seems to be distorted and far different form AUTOCAD design due to many process and chemical involved during fabrication.…”

“…with various geometries and assembling it direct us into a powerful general platform for the ultrasensitive direct electrical detection of biological and chemical species, a device for detecting disease such as cancer, dengue etc, cells at earliest stage. The sensor renders the electric signal when it had found the particular target [6][7][8][9][10]. It had been design to bind with complementary target in the cell.…”