Metal nitride material for thermistor, method for producing same, and film type thermistor sensor

Patent metadata

Field	Value
Publication number	US-9905341-B2
Application number	US-201314380997-A
Country	US
Kind code	B2
Filing date	Feb 26, 2013
Priority date	Feb 28, 2012
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

Provided are a metal nitride material for a thermistor, which exhibits high reliability and high heat resistance and can be directly deposited on a film or the like without firing, a method for producing the metal nitride material for a thermistor, and a film type thermistor sensor. The metal nitride material for a thermistor consists of a metal nitride represented by the general formula: Ti x Al y N z (where 0.70≦y/(x+y)≦0.95, 0.4≦z≦0.5, and x+y+z=1), and the crystal structure thereof is a hexagonal wurtzite-type single phase.

First claim

What is claimed is:

1. A thermistor made of a metal nitride material, the metal nitride material consisting of a metal nitride represented by the general formula: TixAlyNz (where 0.70≦y/(x+y)≦0.95, 0.4≦z≦0.5, and x+y+z=1), wherein the crystal structure thereof is a hexagonal wurtzite-type single phase, wherein the rising rate of specific resistance at 25° C. after heat resistance test at 125° C. for 1,000 hours is less than 5%.

2. The thermistor according to claim 1 , wherein the metal nitride material is deposited as a film and is a columnar crystal extending in a vertical direction to a surface of the film.

3. The thermistor according to claim 1 , wherein the metal nitride material is deposited as a film and is strongly oriented along a c-axis more than an a-axis in a vertical direction to a surface of the film.

4. A film type thermistor sensor comprising:
an insulating film;
a thin film thermistor portion made of the metal nitride material according to claim 1 on the insulating film; and
a pair of pattern electrodes formed at least on the top or the bottom of the thin film thermistor portion.

5. A method for producing the thermistor according to claim 1 , the method comprising:
a depositing step of performing film deposition by reactive sputtering in a nitrogen-containing atmosphere using a Ti-Al alloy sputtering target.

6. The method for producing the thermistor according to claim 5 , wherein a sputtering gas pressure during the reactive sputtering is set to less than 0.67 Pa.

7. The method for producing the thermistor according to claim 5 , the method comprising:
a step of irradiating the formed film with nitrogen plasma after the depositing step.

8. A thermistor made of a metal nitride material, the metal nitride material consisting of a metal nitride represented by the general formula: TixAlyNz (where 0.70≦y/(x+y)≦0.95, 0.4≦z≦ 0 . 5 , and x+y+z=1), wherein the crystal structure thereof is a hexagonal wurtzite-type single phase, wherein the B constant thereof calculated based on resistance values at temperatures of 25° C. and 50° C. is 1500 K or greater.

9. The thermistor according to claim 8 , wherein the metal nitride material is deposited as a film and is a columnar crystal extending in a vertical direction to a surface of the film.

10. The thermistor according to claim 8 , wherein the metal nitride material is deposited as a film and is strongly oriented along a c-axis more than an a-axis in a vertical direction to a surface of the film.

11. A film type thermistor sensor comprising:
an insulating film;
a thin film thermistor portion made of the metal nitride material according to claim 8 on the insulating film; and
a pair of pattern electrodes formed at least on the top or the bottom of the thin film thermistor portion.

12. A thermistor made of a metal nitride material, the metal nitride material consisting of a metal nitride represented by the general formula: TixAlyNz (where 0.70≦y/(x+y)≦0.95, 0.4≦z≦0.5, and x+y+z=1), wherein the crystal structure thereof is a hexagonal wurtzite-type single phase, wherein the specific resistivity value thereof is 100 Ωcm or greater.

13. The thermistor according to claim 12 , wherein the metal nitride material is deposited as a film and is a columnar crystal extending in a vertical direction to a surface of the film.

14. The thermistor according to claim 12 , wherein the metal nitride material is deposited as a film and is strongly oriented along a c-axis more than an a-axis in a vertical direction to a surface of the film.

15. A film type thermistor sensor comprising:
an insulating film;
a thin film thermistor portion made of the metal nitride material according to claim 12 on the insulating film; and
a pair of pattern electrodes formed at least on the top or the bottom of the thin film thermistor portion.

Assignees

• Mitsubishi Materials Corp

Inventors

• Fujita Toshiaki
• Tanaka Hiroshi
• Inaba Hitoshi
• Fujiwara Kazutaka
• Nagatomo Noriaki

Classifications

• H01C7/008 Primary

  Thermistors (H01C7/02 - H01C7/06 take precedence) · CPC title

• H01C17/12

  by sputtering · CPC title

• H01C7/023

  containing oxides or oxidic compounds, e.g. ferrites · CPC title

• G01K7/22

  the element being a non-linear resistance, e.g. thermistor (G01K7/26 takes precedence) · CPC title

• H01C7/043

  Oxides or oxidic compounds · CPC title