Thermistor with tunable resistance

Patent metadata

Field	Value
Publication number	US-11047746-B2
Application number	US-202016852659-A
Country	US
Kind code	B2
Filing date	Apr 20, 2020
Priority date	Jun 30, 2017
Publication date	Jun 29, 2021
Grant date	Jun 29, 2021

Abstract

A device having a first terminal region and a second terminal region. The first terminal region includes fine-tune (FT) metal stripes that are separated from each other by a first distance along the longitudinal direction. The second terminal region is spaced apart from the first terminal region by at least an inter-terminal distance. The second terminal region includes coarse-tune (CT) metal stripes that are separated from each other by a second distance along the longitudinal direction. The second distance is greater than the first distance, and the inter-terminal distance greater than the second distance. Each of the FT metal stripes may be selected as a first access location, and each of the CT metal stripes may be selected as a second access location. A pair of selected first and second access locations access a sheet resistance defined by a distance therebetween.

First claim

What is claimed is:

1. A device, comprising:
a substrate having a top surface and the substrate having a first dopant conductivity type;
a doped region formed in the substrate and extending into the substrate from the top surface of the substrate to a depth, the doped region having a second dopant conductivity type opposite to the first dopant conductivity type;
a first access doped region formed in the doped region;
a second access doped region formed in the doped region and laterally spaced from the first access doped region by a first distance;
a third access doped region formed in the doped region and laterally spaced from the first access doped region by a second distance that is greater than the first distance; and
wherein a first resistance from the first access doped region to the third access doped region is greater than a second resistance from the first access doped region to the second access doped region.

2. The device of claim 1 , wherein:
the first resistance is defined by: the first distance a sheet resistance along the substrate within the doped region; and
the second resistance is defined by: a second distance and the sheet resistance.

3. The device of claim 1 , wherein the second resistance is a summation of the first resistance and a third resistance defined between the second access doped region and the third access doped region.

4. The device of claim 1 , wherein the first distance is at least 10 times greater than the second distance.

5. The device of claim 1 , further comprising:
a first isolation structure positioned between the second access doped region and the third access doped region; and
a second isolation structure positioned between the first access doped region and the second access doped region, the second isolation structure at least 10 times longer than the first isolation structure.

6. The device of claim 1 , further comprising:
a first conductive interconnection connected to the first access doped region;
a second conductive interconnection connected to the second access doped region; and
a third conductive interconnection connected to the third access doped region.

7. The device of claim 6 , further comprising:
a fuse coupled to the second access doped region;
a bond pad coupled to the fuse and the third conductive interconnection.

8. The device of claim 1 , further comprising:
a first fuse coupled to the second access doped region;
a second fuse coupled to the third access doped region; and
a bond pad coupled to the first fuse and the second fuse.

9. The device of claim 1 , wherein each of the first access doped region, the second access doped region, and the third access doped are formed of the second dopant conductivity type and have a higher doping concentration than the doped region.

10. The device of claim 1 , wherein the first dopant conductivity type is p-type, and the second dopant conductivity type is n-type.

11. A thermistor, comprising:
a substrate having a top surface and the substrate having a first dopant conductivity type;
a doped region formed in the substrate and extending into the substrate from the top surface of the substrate to a depth, the doped region having a second dopant conductivity type opposite to the first dopant conductivity type;
a first access doped region formed in the doped region;
a second access doped region formed in the doped region and laterally spaced from the first access doped region by a first distance;
a third access doped region formed in the doped region and laterally spaced from the first access doped region by a second distance that is greater than the first distance; and
wherein a first resistance from the first access doped region to the third access doped region is greater than a second resistance from the first access doped region to the second access doped region.

12. The device of claim 11 , further comprising:
a first isolation structure positioned between the second access doped region and the third access doped region; and
a second isolation structure positioned between the first access doped region and the second access doped region, the second isolation structure at least 10 times longer than the first isolation structure.

13. The device of claim 11 , further comprising:
a first conductive interconnection connected to the first access doped region;
a second conductive interconnection connected to the second access doped region; and
a third conductive interconnection connected to the third access doped region.

14. The device of claim 13 , further comprising:
a fuse coupled to the second access doped region;
a bond pad coupled to the fuse and the third conductive interconnection.

15. The device of claim 11 , further comprising:
a first fuse coupled to the second access doped region;
a second fuse coupled to the third access doped region; and
a bond pad coupled to the first fuse and the second fuse.

16. The device of claim 11 , wherein each of the first access doped region, the second access doped region, and the third access doped are formed of the second dopant conductivity type and have a higher doping concentration than the doped region.

17. The device of claim 11 , wherein the first dopant conductivity type is p-type and the second dopant conductivity type is n-type.

18. A device having a resistor network including a first resistor and a second resistor, the selectable resistor network comprising:
a substrate having a top surface and the substrate having a first dopant conductivity type;
a doped region formed in the substrate and extending into the substrate from the top surface of the substrate to a depth, the doped region having a second dopant conductivity type opposite to the first dopant conductivity type;
a first access doped region formed in the doped region;
a second access doped region formed in the doped region and laterally spaced from the first access doped region by a first distance;
a third access doped region formed in the doped region and laterally spaced from the first access doped region by a second distance that is greater than the first distance; and
wherein the first resistor is formed by a first resistance from the first access doped region to the third access doped region and the second resistor is formed by a second resistance from the first access doped region to the second access doped region.

Assignees

• Texas Instruments Inc

Inventors

• Green Keith Ryan
• Shulver Byron Jon Roderick

Classifications

• G01K7/01

  using semiconducting elements having PN junctions (G01K7/02, G01K7/16, G01K7/30 take precedence) · CPC title

• G01K7/223

  characterised by the shape of the resistive element · CPC title

• G01K2007/163

  provided with specially adapted connectors · CPC title

• G01K7/023

  provided with specially adapted connectors (connectors per se H01R) · CPC title

• G01K15/005

  Calibration · CPC title