# US 2021/0239666 A1 · Hydrogen sensor having vertical nanogap structure and method for manufacturing the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0239666 A1 - Document ID: US20210239666A1 - Status: Published application - Kind: A1 - Application number: 17/148,242 - Filed: 2021-01-13 - Published: 2021-08-05 - Earliest claimed: 2020-01-31 - Assignees: Korea Institute of Science and Technology - Applicants: Korea Institute of Science and Technology - Inventors: Deok Ha WOO; Yusin PAK - Web page: https://patentgrep.com/patent/US20210239666A1 ## CPC - G01N 33/005: {H2} - H10P 14/60: of insulating materials - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract The present disclosure relates to a hydrogen sensor and a method for manufacturing the same, and more particularly, to a hydrogen sensor having a vertical nanogap structure, in which a nanogap is formed below a sensor portion to bring the sensor portion and an electrode into contact with each other when the sensor portion reacts with hydrogen, so as to allow the sensor portion to expand and contract freely without resistance on a substrate, thereby improving hydrogen sensing accuracy, and it is possible to form a precise nanogap with uniformity and reproducibility at a low cost and a method for manufacturing the same. ## Claims ### Claim 1 A hydrogen sensor, comprising: a substrate having an electrode, a sensor portion spaced a predetermined distance apart from an upper surface of the substrate, and a nanogap formed by vertical separation of the substrate and the sensor portion, wherein the sensor portion is made of a material that expands in reaction with hydrogen, and in the presence of hydrogen, the sensor portion expands and comes into contact with the underlying electrode. ### Claim 2 (depends on 1) The hydrogen sensor according to claim 1, further comprising: a support portion coupled to the upper surface of the substrate to support the sensor portion such that the sensor portion is spaced the predetermined distance apart from the substrate, the support portion being made of an insulating material. ### Claim 3 (depends on 2) The hydrogen sensor according to claim 2, wherein the support portion includes a first support portion coupled to the upper surface of the substrate, and a second support portion coupled to the upper surface of the substrate, spaced a predetermined distance apart from the first support portion in a horizontal direction, and the sensor portion includes a seating portion seated on an upper surface of the support portion, and a protrusion protruding downwards from a lower surface of the seating portion and disposed between the first support portion and the second support portion. ### Claim 4 (depends on 3) The hydrogen sensor according to claim 3, wherein the protrusion is spaced a predetermined distance apart from the substrate in a vertical direction to form a nanogap between an end of the protrusion and the substrate, and is spaced a predetermined distance apart from the support portion in a horizontal direction to prevent a contact with the support portion disposed on the outside of the protrusion during expansion of the protrusion. ### Claim 5 (depends on 2) The hydrogen sensor according to claim 2, wherein the support portion includes a first support portion coupled to the upper surface of the substrate, and a second support portion coupled to the upper surface of the substrate, spaced a predetermined distance apart from the first support portion in a horizontal direction, and the sensor portion includes a top portion seated on an upper surface of the first support portion or the second support portion with an end disposed at an upper part between the first support portion and the second support portion, and a protrusion protruding from a lower surface of the top portion and disposed between the first support portion and the second support portion, spaced a predetermined distance apart from the substrate. ### Claim 6 (depends on 5) The hydrogen sensor according to claim 5, wherein the protrusion is spaced a predetermined distance apart from the substrate in a vertical direction to form the nanogap between an end of the protrusion and the substrate, and is spaced a predetermined distance apart from the support portion in a horizontal direction to prevent a contact with the support portion disposed on the outside of the protrusion during expansion of the protrusion. ### Claim 7 A method for manufacturing a hydrogen sensor, comprising: a first sacrificial layer formation step of forming a first sacrificial layer on a substrate having an electrode to a predetermined thickness, a support portion formation step of forming a support portion having insulating properties on the outside of the first sacrificial layer, spaced a predetermined distance apart from the first sacrificial layer after the first sacrificial layer formation step, a second sacrificial layer formation step of forming a second sacrificial layer having a spacer disposed between the first sacrificial layer and the support portion and a side protrusion protruding from a side of the spacer to a predetermined length and disposed at part of an upper surface of the first sacrificial layer after the support portion formation step, a sensor portion formation step of forming a sensor portion supported on the support portion with an end contacting the first sacrificial layer through deposition of a metal that expands in reaction with hydrogen after the second sacrificial layer formation step, and a nanogap formation step of forming a nanogap by removing the first sacrificial layer and the second sacrificial layer after the sensor portion formation step, wherein a thickness of the nanogap formed by the separation of the substrate and the sensor portion is adjusted by adjusting a thickness of the first sacrificial layer. ### Claim 8 A method for manufacturing a hydrogen sensor, comprising: a first sacrificial layer formation step of forming a first sacrificial layer on a substrate having an electrode to a predetermined thickness, a support portion formation step of forming a support portion having insulating properties on the outside of the first sacrificial layer, spaced a predetermined distance apart from the first sacrificial layer after the first sacrificial layer formation step, a protrusion formation step of forming a protrusion on the first sacrificial layer to a predetermined thickness through deposition of a metal that expands in reaction with hydrogen after the support portion formation step, a second sacrificial layer formation step of forming a second sacrificial layer having a spacer disposed between the first sacrificial layer and the support portion and a side protrusion protruding from a side of the spacer to a predetermined length with a lower surface contacting an upper surface of the first sacrificial layer and a side contacting a side of the protrusion after the protrusion formation step, a seating portion formation step of forming a seating portion supported on the support portion and contacting the protrusion at a central area of a lower surface through deposition of a metal that expands in reaction with hydrogen after the second sacrificial layer formation step, and a nanogap formation step of forming a nanogap by removing the first sacrificial layer and the second sacrificial layer after the seating portion formation step, wherein a thickness of the nanogap formed by the separation of the substrate and the sensor portion is adjusted by adjusting a thickness of the first sacrificial layer. ### Claim 9 (depends on 7) The method for manufacturing a hydrogen sensor according to claim 7, wherein the substrate is made of a conductive material or is an insulating substrate coated with a conductive material, the first sacrificial layer is made of silicon dioxide (SiO2), the support portion is made of aluminum oxide (Al2O3), and the second sacrificial layer is made of polyvinyl alcohol (PVA) that is dissolved in water.