Thin films having large temperature coefficient of resistance and methods of fabricating same

Patent metadata

Field	Value
Publication number	US-9664572-B2
Application number	US-201213687445-A
Country	US
Kind code	B2
Filing date	Nov 28, 2012
Priority date	Nov 28, 2012
Publication date	May 30, 2017
Grant date	May 30, 2017

Abstract

An apparatus comprises a head transducer and a resistive temperature sensor provided on the head transducer. The resistive temperature sensor comprises a first layer comprising a conductive material and having a temperature coefficient of resistance (TCR) and a second layer comprising at least one of a specular layer and a seed layer. A method is disclosed to fabricate such sensor with a laminated thin film structure to achieve a large TCR. The thicknesses of various layers in the laminated thin film are in the range of few to a few tens of nanometers. The combinations of the deliberately optimized multilayer thin film structures and the fabrication of such films at the elevated temperatures are disclosed to obtain the large TCR.

First claim

What is claimed is:

1. An apparatus, comprising:
a head transducer; and
a resistive temperature sensor provided at a close point within the head transducer and configured to sense for one or both of head-media contact and thermal asperities, the sensor comprising:
a first layer comprising a conductive material and having a temperature coefficient of resistance; and
a second layer comprising at least one of a specular layer and a seed layer.

2. The apparatus of claim 1 , wherein the conductive material comprises Cu, Co, Ni, Ru, Pt, Au, Fe, or Ni X Fe 1-X , or their alloys.

3. The apparatus of claim 1 , wherein the sensor comprises a cap layer on the first layer, the cap layer comprising Ta, Ru, Cr, NiCr, or NiRu, or their alloys.

4. The apparatus of claim 1 , wherein the first layer has a thickness approximately equal to or less than a mean-free-path of an electron in the conductive material of the first layer.

5. The apparatus of claim 1 , wherein the second layer comprises the specular layer.

6. The apparatus of claim 5 , wherein the specular layer comprises an insulator layer.

7. The apparatus of claim 6 , wherein the insulator layer comprises SiO 2 , NiO, Al 2 O 3 , FeO X , HfO 2 , Y 2 O 3 , MgO, TiO X , CuO X , SrTiO 3 , or ZrO.

8. The apparatus of claim 5 , wherein the specular layer comprises a metal layer.

9. The apparatus of claim 8 , wherein the metal layer comprises Au, Ag, Cu, Pt, or Ru, or their alloys.

10. The apparatus of claim 5 , further comprising at least one flash metal layer between the first layer and the specular layer.

11. The apparatus of claim 10 , wherein the flash layer comprises Cu, Ag, or Au, or their alloys.

12. The apparatus of claim 5 , wherein the sensor comprises a plurality of the first layers and a plurality of the specular layers.

13. The apparatus of claim 5 , wherein the specular layer has a specularity of about 0.2 to about 0.8.

14. The apparatus of claim 1 , wherein the second layer comprises the seed layer.

15. The apparatus of claim 14 , wherein the seed layer comprises Ta, Ru, Cr, NiCr, or NiRu, or their alloys.

16. A method, comprising:
fabricating, at a close point within a head transducer, a resistive temperature sensor configured for sensing one or both of head-media contact and thermal asperities, the fabricating comprising:
forming, on the head transducer, a first layer comprising a conductive material having a temperature coefficient of resistance; and
forming, on the head transducer, a second layer comprising at least one of a specular layer and a seed layer.

17. The method of claim 16 , wherein forming the first layer comprises forming the first layer to a thickness approximately equal to or less than a mean-free-path of an electron in the conductive material of the first layer.

18. The method of claim 16 , wherein the conductive material comprises Cu, Co, Ni, Ru, Pt, Au, Fe, or Ni X Fe 1-X , or their alloys.

19. The method of claim 16 , comprising forming a cap layer over the first layer, the cap layer comprising Ta, Ru, Cr, NiCr, or NiRu, or their alloys.

20. The method of claim 16 , wherein forming the second layer comprises forming the specular layer comprising SiO 2 , NiO, Al 2 O 3 , FeO X , HfO 2 , Y 2 O 3 , MgO, TiO X , CuO X , SrTiO 3 , or ZrO.

21. The method of claim 16 , wherein forming the second layer comprises forming the specular layer comprising Au, Ag, Cu, Pt, or Ru, or their alloys.

22. The method of claim 16 , comprising forming a flash metal layer between the first layer and the second layer, wherein:
forming the second layer comprises forming the specular layer; and
forming the flash metal layer comprises forming a flash material comprising Cu, Ag, or Au, or their alloys.

23. The method of claim 16 , wherein forming the second layer comprises forming the seed layer comprising Ta, Ru, Cr, NiCr, or NiRu, or their alloys.

24. The method of claim 16 , wherein:
forming the second layer comprises forming the seed layer; and
forming the seed and conducting layers is performed in situ in a high vacuum environment.

25. The method of claim 16 , wherein:
forming the second layer comprises forming the seed layer; and
forming the seed and conducting layers is performed at an elevated temperature relative to room temperature.

Assignees

• Seagate Technology Llc

Inventors

• Tian Wei
• Macken Declan
• Yin Huaqing
• Inturi Venkateswara Rao
• Singleton Eric Walter

Classifications

• H01C7/021

  formed with two or more layers · CPC title

• H01C7/006

  Thin film resistors · CPC title

• G01K7/16 Primary

  using resistive elements · CPC title

• H01C7/008

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

• H01C7/06

  including means to minimise changes in resistance with changes in temperature · CPC title