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

Patent metadata

Field	Value
Publication number	US-9852829-B2
Application number	US-201314380791-A
Country	US
Kind code	B2
Filing date	Feb 21, 2013
Priority date	Feb 28, 2012
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

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 1-w O w ) z (where 0.70≦y/(x+y)≦0.95, 0.45≦z≦0.55, 0<w≦0.35, 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: Ti x Al y (N 1-w O w ) z (where 0.70≦y/(x+y)≦0.95, 0.45≦z≦0.55, 0≦w≦0.35, and x+y+z=1), wherein the crystal structure thereof is a hexagonal wurtzite-type single phase.

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 the 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 for the thermistor 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 an atmosphere containing nitrogen and oxygen 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.

Assignees

• Mitsubishi Materials Corp

Inventors

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

Classifications

• H01C7/04

  having negative temperature coefficient · CPC title

• H01C7/008 Primary

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

• C30B29/38

  Nitrides · CPC title

• C23C14/0036

  Reactive sputtering · CPC title

• C23C14/0641

  Nitrides (C23C14/0617 takes precedence) · CPC title