Fabrication and characterization of a-Si micro and nano-gap structure for electrochemical sensor

Abstract

The development and application of micro and nanogap for electrochemical sensors and biomoleculs detection are reviewed in this article. The preparation methods of micro and nanogap and their properties are discussed along with their advantages towards electrochemical sensors and biomolecules detection. In the recent year, the biological and medical field has seen great advances in the development of biosensors and biochips capable of characterizing and quantifying electrochemical sensor. To understand the important relationship between the sensibility and nano structure we introduce this article about the fabrication and characterization of micro and nanogap structure for electrochemical sensor. In this paper, 2 masks designs are proposed. First mask is the lateral micro and nanogap with Al electrode and the second mask is for pad Al electrode pattern. Lateral micro gaps are introduced in the fabrication process using a-silicon and Al as an electrode. Conventional UV lithography technique and dry etching for a-Si layer with wet etching for Al surface processes are used to fabricate the micro and nanogap based on the standard CMOS technology and characterization of its conductivity. The electrical characterization are applied by using Semiconductor Parameter Analyzer (SPA), Spectrum Analyzer, IV–CV Station for electrical characteristic, Conductivity, resistivity and capacitance test is performed to characterize and check the structure of the device, which resulted in a small microgap as was revealed by further I–V curve result that showed a current in nano amps. On verification with literature the characteristics of the fabricated gap was close to that of a microgap.