Fabrication Of Nanopore And Nanopore Integrated With Nanoelectrodes

Nanopore has become a hotspot, which was a new generation of single molecule detection technology. Nowadays, many materialsand methods have been used in the fabrication of solid-state nanopore, particularly, silicon nitride has been mostly used for fabrication of nanopore by the focus ion beam. This kind of solid-state nanopore has been widely used for single molecular sensing of different kinds of molecular, such as DNA, RNA, protein and nanoparticles. So the demand of different diameters of nanopore is increasing constantly.In this thesis, the fabrication of solid-state nanopore and the nanopore integrated with nanoelectrodes has been suited, and the distribution of diameters were analyzed. The characteristic of nanopores and the translocation events of nanopore have been discussed systematically. The main content of this thesis is composed of the following parts:1. The micro-fabrication techniques of MEMS and nano-fabrication of Focus Ion Beam (FIB) were used for fabrication the flim of solid-state nanopores and nanopore arrays. At first, The free-stand Si3N4 film with square of 50 μm ×50 μm was fabricated repeatedly. Secondly, The FIB (Strata FIB 201) of Ga+was used to drill the nanopores on silicon nitride film. In the modes of spot and circle, solid-state nanopores can be fabricated stably. And the solid-state nanopores were used for nanopore detection experiments.2. The Dual-beam Focused Ion Beam(DB-FIB) and Helium Ion Microscope (HIM) were used to drill nanopores with smaller diameters on the free-stand silicon nitride. The free-stand silicon nitride has two kinds of thickness, including 100 nanometers and 30 nanometers. DB-FIB can be used to dill nanopores with diameters from 10 nanometers to 60 nanometers. HIM can be used to drill nanopores with diameters from 2 nanometers and 60 nanometers. This make up the lack of diameters which were fabricated of FIB. And it expands the scope of the diameters. The widely range of diameters can meet the various requirements for nanopore detection experiments.And it established a solid foundation of the fabrication of nanoelectrodes.3. The micro-fabrication techniques and nano-fabrication were used to fabricate the nanopore integrated with nanoelectrodes. Firstly, The gold nanoelectrodes with thickness of 50 nm and width of 5 μm on the free-stand silicon nitride film was fabricated by MEMS. Secondly,DB-FIB was used to do the preliminary etching. And HIMwas use to fine the width of the nanoelectrodes. By the two step of etching, nanoelectrodes with width of 10 nm was conformed. Then,100 nm thickness of silicon nitride as an insulating layer was deposition by PECVD. Thisform the structure of sandwich, "silicon nitride-gold-silicon nitride". Finally, HIM was used to drill a nanopore integrated with nanoelectrodes, whose diameter is about 10 nm.Nanopore and nanopore integrated with nanoelectrodes was fabricated by the micro-fabrication techniques and nano-fabrication. Onthis basis, tunneling current can be detection in the future.