Thermistor method made of metal nitride material, method for producing same, and film type thermistor sensor
Provided are a metal nitride material for a thermistor, which has a high reliability and a high heat resistance and can be directly deposited on a film or the like without firing, a method for producing the same, and a film type thermistor sensor. The metal nitride material for a thermistor consists of a metal nitride represented by the general formula: Cr x Al y N z (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. The method for producing the metal nitride material for a thermistor includes a deposition step of performing film deposition by reactive sputtering in a nitrogen-containing atmosphere using a Cr—Al alloy sputtering target.
1. A thermistor, consisting of a metal nitride represented by the general formula: Cr x Al y N z (0.70≦y/(x+y) ≦0.95, 0.4≦z≦0.5, and x+y+z=1), wherein the crystal structure of the metal nitride 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 with respect to the surface of the film.
3. The thermistor according to claim 1 , wherein the metal nitride material is deposited as a film and is more strongly oriented along a c-axis than an a-axis in a vertical direction with respect to the surface of the film.
4. A film type thermistor sensor comprising:
an insulating film;
a thin film thermistor portion 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. The film type thermistor sensor according to claim 4 , wherein at least a portion of a pair of the pattern electrodes that is bonded to the thin film thermistor portion is made of Cr.
6. A method for producing the thermistor according to claim 1 , the method comprising a deposition step of performing film deposition by reactive sputtering in a nitrogen-containing atmosphere using a Cr—Al alloy sputtering target.
7. The method for producing the thermistor according to claim 6 , wherein the sputtering gas pressure during the reactive sputtering is set to less than 0.67 Pa.
8. The method for producing the thermistor according to claim 6 , the method comprising a step of irradiating the formed film with nitrogen plasma after the deposition step.