Surface-sensitive condenser type gas transducer and manufacturing method thereof

A gas sensor, surface-sensitive technology, applied in semiconductor/solid-state device manufacturing, electrical components, circuits, etc., can solve problems such as dielectric constant change of dielectric layer, complex semiconductor manufacturing process, and influence on capacitance test effect, so as to reduce test voltage , reduce interference and avoid loss

Inactive Publication Date: 2008-01-23
HEFEI INSTITUTES OF PHYSICAL SCIENCE - CHINESE ACAD OF SCI
View PDF3 Cites 15 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the field ionization gas sensor has a great disadvantage in structure. The sensor must ionize the gas to be measured, and the ionized gas reaches the counter electrode to form a current to obtain the detection signal. The ion will be complicated during the movement process. The reaction (such as transfer, recombination, etc.) causes the ion charge to be lost, so there is some randomness in the detection results
[0004] E.S.Snow et al. proposed a single-walled carbon nanotube sensor using the capacitance pr...

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Surface-sensitive condenser type gas transducer and manufacturing method thereof
  • Surface-sensitive condenser type gas transducer and manufacturing method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0041] The fabrication process of the surface-sensitive capacitive gas sensor is as follows: first, the silicon wafer 1 is heavily doped (with a resistivity of 0.001Ω·cm) and used as the first electrode. Then thermally oxidize a 200nm silicon oxide layer on the upper surface of the silicon wafer 1, and then make a layer of gold electrode on the silicon oxide 2 by screen printing, and make a layer of iron electrode on the surface by magnetron sputtering. film.

[0042] Put the finished sample into a tube furnace and use the method of vapor deposition to make a carbon nanotube film. The specific process is: first pass argon gas at a flow rate of 100ml / min for 2 hours to evacuate the air in the tube, and heat it to 600°C. Then flow hydrogen at a flow rate of 100ml / min for 2 hours to reduce the oxidized iron film, and then flow acetylene gas at a flow rate of 15ml / min to start depositing carbon nanotubes. After half an hour, stop heating, turn off acetylene and hydrogen, and cool ...

Embodiment 2

[0044] The manufacturing process of the surface-sensitive capacitive gas sensor is as follows: screen-print a layer of gold paste on the lower surface of the silicon wafer 1, burn it at 820°C for 20 minutes, and then coat a layer of 150nm gold paste on the upper surface of the silicon wafer 1 by sputtering. Silicon oxide 2, on top of the silicon oxide 2, a layer of gold electrode is made by screen printing, and a layer of iron film is made on its surface by magnetron sputtering.

[0045] Put the finished sample into a tube furnace and use the method of vapor deposition to make a carbon nanotube film. The specific process is: first pass argon gas at a flow rate of 200ml / min for 2 hours to evacuate the air in the tube, and heat it to 800°C. Then flow hydrogen at a flow rate of 200ml / min for 1 hour to reduce the oxidized iron film, and then flow acetylene gas at a flow rate of 10ml / min to start depositing carbon nanotubes. After half an hour, stop heating, turn off acetylene and h...

Embodiment 3

[0047] The fabrication process of the surface-sensitive capacitive gas sensor is as follows: first, the silicon wafer 1 is heavily doped (with a resistivity of 0.01 Ω·cm), and then a layer of thermal evaporation is deposited on the lower surface of the silicon wafer 1 under vacuum at 200°C. A gold electrode is then thermally oxidized 100nm silicon oxide 2 on the upper surface of the silicon wafer 1, and a layer of gold electrode is made on the silicon oxide 2 by screen printing.

[0048] Zinc oxide nano or microrod arrays were prepared by hydrothermal method, the preparation process is as follows: 30ml 0.5M NaOH solution, 5ml 30% H 2 o 2 Add the solution into an autoclave with a volume of 50ml, stir evenly, add a piece of 1cm×1cm pure and flat zinc sheet, seal it, put it in an oven and heat it to 160-200°C for 1-10 hours. After the reaction, take out the zinc sheet, wash it with deionized water and alcohol, and dry it in a vacuum oven at 40°C for 20 minutes to obtain a zinc o...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
Resistivityaaaaaaaaaa
Resistivityaaaaaaaaaa
Diameteraaaaaaaaaa
Login to view more

Abstract

The invention relates to a surface sensitive capacitance gas sensor and its making method, which comprises in sequence a first electrode, a silicon wafer, a silicon oxide, a second electrode and a film of sensitive material. The silicon oxide in the sensor acts as electric medium, and forms a plate capacitor between the silicon wafer and the second electrode; the film of sensitive material is placed on the outer surface of a pole plate of the plate capacitor. By taking use of the characteristic that a nanometer or micrometer material has a small tip curve radius, the gas to be tested is polarized to increase or decrease the electric charge on the plate capacitor; and the type of the tested gas is judged through the surface sensitive capacitance gas sensor by the change reflected by the capacitance signals. The surface sensitive capacitance gas sensor operates under normal temperature and pressure, avoids any influence of accumulation of gas adsorbed by the sensitive material on the dielectric constant of the medium layer, improves the steadiness, selectivity, signal to noise ratio, accuracy and sensibility of the surface sensitive capacitance gas sensor.

Description

[0001] Field of the Invention The present invention relates to the field of gas detection, in particular to a surface-sensitive capacitive gas sensor based on the fringe field effect of one-dimensional nano or micro materials and its manufacturing method. Background technique [0002] There are many types of gas sensors, such as oxide semiconductor gas sensors, solid electrolyte gas sensors, electrochemical gas sensors, metal gate MOS gas sensors, surface acoustic wave gas sensors, infrared gas sensors, etc. With the rise of nanotechnology, the excellent performance of nanomaterials has led to the rapid development of the field of sensors. Nanoparticles often have a large specific surface area, and the specific surface area per gram of this solid can reach hundreds or even thousands of square meters, which makes them useful as highly active adsorbents and catalysts, using nanoparticles and nanofilms to modify traditional Gas sensors such as oxide semiconductors, solid-state el...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): G01N27/20H01L21/00
Inventor 孟凡利刘锦淮李民强贾勇陈星黄家锐
Owner HEFEI INSTITUTES OF PHYSICAL SCIENCE - CHINESE ACAD OF SCI
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap