KR-102959370-B1 - METHOD OF MANUFACTURING NANO GAP PLATFORM

KR102959370B1KR 102959370 B1KR102959370 B1KR 102959370B1KR-102959370-B1

Abstract

The present invention relates to a method for manufacturing a nano-gap platform, comprising: (a) forming a first silicon nitride layer and a second silicon nitride layer on each of the two surfaces of a silicon wafer; (b) applying a mask layer having a rectangular mask pattern formed on the surface of the first silicon nitride layer; (c) etching the region of the first silicon nitride layer exposed by the mask pattern to expose the surface of the silicon wafer; (d) etching the region of the silicon wafer exposed in step (c) to expose the surface of the second silicon nitride layer inside the silicon wafer; (e) milling the surface of the second silicon nitride layer exposed inside the silicon wafer to form a pair of notch patterns facing each other, wherein the pointed corner regions of each of the pair of notch patterns face each other and are spaced apart, and a bridge region is formed between the facing corner regions; and (f) forming a nano-gap by a crack occurring in the bridge region in a direction connecting the pair of notch patterns.

Inventors

장승민
이병양
곽다인

Assignees

고려대학교 산학협력단

Dates

Publication Date: 20260507
Application Date: 20230228
Priority Date: 20220228

Claims (13)

(a) a step of forming a first silicon nitride layer and a second silicon nitride layer on each of the two surfaces of a silicon wafer; (b) a step of applying a mask layer having a rectangular mask pattern formed on the surface of the first silicon nitride layer; and (c) a step of etching the region of the first silicon nitride layer exposed by the mask pattern to expose the surface of the silicon wafer; and (d) a step of etching the region of the silicon wafer exposed in step (c) above to expose the surface of the second silicon nitride layer inside the silicon wafer; and (e) a step of milling the surface of the second silicon nitride layer exposed inside the silicon wafer to form a pair of mutually facing notch patterns - wherein the pointed edge regions of each of the pair of notch patterns are spaced apart and face each other, and a bridge region is formed between the mutually facing edge regions - and; (f) a step of forming a nano gap by a crack occurring in a direction connecting a pair of notch patterns in the bridge region, and The above (e) step (e1) A step of milling the surface of the second silicon nitride layer exposed inside the silicon wafer to form a first region and a second region of a rectangular shape - the first region and the second region are spaced apart from each other in a first direction and are spaced apart from each other by a partition wall extending in a second direction intersecting the first direction by the unmilled second silicon nitride layer - and; (e2) The step of forming a pair of notch patterns facing in the first direction in the middle region of the partition wall, and The above partition wall is divided into a first cantilever and a second cantilever in the second direction by the nano gap formed in step (f), and (g) A method for manufacturing a nano-gap platform, further comprising the step of applying a conductive metal to the surface of the first cantilever and the second cantilever.
In paragraph 1, A method for manufacturing a nano-gap platform, characterized in that in step (f) above, the crack occurs when the local stress in the bridge region of the second silicon nitride layer exceeds the strength of the second silicon nitride layer.
In paragraph 2, A method for manufacturing a nano-gap platform, characterized in that the crack in step (f) above occurs due to the shrinkage of the second silicon nitride layer caused by stress concentration in a direction traversing between a pair of notch regions after the fracture of the bridge region due to the local stress.
In paragraph 1, A method for manufacturing a nano-gap platform, characterized in that in step (a) above, the first silicon nitride layer and the second silicon nitride layer are deposited on the silicon wafer through a chemical vapor deposition technique.
In paragraph 1, The above step (b) (b1) a step of applying a positive photoresist to the first silicon nitride layer through spin coating; (b2) A method for manufacturing a nano-gap platform characterized by including the step of forming the mask layer by forming the mask pattern on the positive photoresist through a developing technique.
In paragraph 1, A method for manufacturing a nano-gap platform, characterized in that in step (c) above, the region of the first silicon nitride layer exposed by the mask pattern is etched through dry etching using reactive ion etching.
In paragraph 1, A method for manufacturing a nano-gap platform characterized by milling the surface of the second silicon nitride layer using a focused ion beam (FIB) in step (e) above.
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In Paragraph 7, A method for manufacturing a nano-gap platform characterized by applying a metal through deposition using an electron beam-induced deposition (EBID) technique in step (g) above.
In paragraph 1, A method for manufacturing a nano-gap platform characterized by further including a step of removing the mask layer between step (c) and step (d).
In Paragraph 12, A method for manufacturing a nano-gap platform characterized by removing the above mask layer through wet etching.

Description

Method of Manufacturing a Nano Gap Platform The present invention relates to a method for manufacturing a nano-gap platform, and more specifically, to Since the discovery of DNA, efforts have been concentrated on developing methods to actually experimentally determine the sequences of its constituent chemical bases. In 1978, Sanger introduced the first method for systematically sequencing DNA. This basic method was automated on commercial instrument platforms in the late 1980s, enabling the first sequencing of the human genome. The success of these efforts spurred the development of numerous "massively parallel" sequencing platforms, aiming to drastically reduce the time and cost required to sequence the human genome. These automated methods generally rely on processing millions to billions of sequencing responses simultaneously in highly miniaturized microfluidic formats. Among technologies related to DNA sequencing, a nano gap refers to the distance between two objects separated by a nanometer-sized distance. A single molecule detection system using a nano gap is a system that uses electrodes separated by nanometer (nm) or sub-nanometer (sub-nm) intervals and monitors tunneling currents across the gap. Existing methods for creating nano gaps have the problem that it is difficult to produce gap sizes of 10 nm or less, and DNA strands cannot pass through the nano gaps. Conventional NGS nucleic acid detection technology, which analyzes base sequences with unknown DNA sequences, is a method that detects changes in ion current based on the degree to which each DNA base passing through the nanopore blocks the nanopore. This method has the problem that it is difficult to control the speed at which DNA passes through the nanopores, and the introduced DNA does not pass through the nanopores effectively. Additionally, it suffers from the problem that the DNA flow rate passing through the nanopores is too fast for measurement, and that the nanopores become clogged over time. Meanwhile, electronic nanogaps are characterized by a rich array of physics, including mechanical, optical, plasma, thermoelectric, electron transport, quantum mechanical spin, and interference-dependent transport phenomena. Electronic nanogaps enable the exploration and detection of molecules, which are two key processes of biosensing based on molecular electrons and electron tunneling, as well as surface plasma. Electron nanogaps are the basic building blocks of ultra-high-speed vacuum transistors and ultra-low-power nanoelectromechanical switches, and tunnel junctions formed between superconducting electrode materials at cryogenic temperatures, so-called Josephson junctions, are important building blocks of quantum information processing devices. However, despite this importance, methods to fabricate electron nanogaps of 10 nm or less remain challenging because there are difficulties in ensuring dimensional and electrode separation in an accurate and reliable manner. Existing electronic nanogap fabrication technologies include mask-defined etching processes, layer-defined sacrificial etching processes, material-growth processes, combinations of layer-defined and material growth processes, self-assembly processes, and electrical breakdown processes. Each of these approaches has serious drawbacks, including limited process control, limited dimensional accuracy, unsuitability for implementing large-scale complex systems, and residual contaminants in the nano-gap. FIGS. 1 and FIGS. 11 are drawings for explaining a method for manufacturing a nano-gap platform according to an embodiment of the present invention. The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the present invention, and the present invention is defined only by the scope of the claims. The terms used in this specification are for describing embodiments and are not intended to limit the invention. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. The terms "comprises" and/or "comprising" used in this specification do not exclude the presence or addition of one or more other components in addition to the components mentioned. Throughout the specification, the same reference numerals refer to the same components, and "and/or" includes each of the mentioned components and all combinations of one or more. Although terms such as "first," "second," etc., are used to describe various components, these components are not limited by these terms. These terms are used merely to distin