High precision resistor and trimming method thereof

Patent metadata

Field	Value
Publication number	US-9429967-B2
Application number	US-201514617984-A
Country	US
Kind code	B2
Filing date	Feb 10, 2015
Priority date	Jun 30, 2010
Publication date	Aug 30, 2016
Grant date	Aug 30, 2016

Abstract

An embodiment of an electrically trimmable electronic device, wherein a resistor of electrically modifiable material is formed by a first generally strip-shaped portion and by a second generally strip-shaped portion, which extend transversely with respect to one another and are in direct electrical contact in a crossing area. The first and second portions have respective ends connected to own contact regions, coupled to a current pulse source and are made of the same material or of the same composition of materials starting from a same resistive layer of the material having electrically modifiable resistivity, for example, a phase-change material, such as a Ge—Sb—Te alloy, or polycrystalline silicon, or a metal material used for thin-film resistors. The trimming is performed by supplying a trimming current to the second portion so as to heat the crossing area and modify the resistivity thereof, without flowing longitudinally in the first portion.

First claim

The invention claimed is:

1. An electronic device comprising:
first and second pairs of contacts; and
a resistor comprising a phase change material so as to have an electrically modifiable resistivity;
said resistor comprising first and second portions extending transversely and in direct electrical contact to each other at a crossing area, at least one of the first and second portions having a varying width;
said first and second portions each having respective ends connected to respective ones of the first and second pairs of contacts.

2. The electronic device according to claim 1 , wherein the first and the second portions are coplanar at least at the crossing area.

3. The electronic device according to claim 1 , wherein the first and the second portions each comprises a Ge—Sb—Te alloy.

4. The electronic device according to claim 1 , wherein at least one of the first and second portions has a constant width.

5. The electronic device according to claim 1 , wherein the at least one of the first and second portions having the variable width includes a minimum width next to the crossing area.

6. The electronic device according to claim 5 , wherein the width of the first portion next to the crossing area is less than the width of the second portion next to the crossing area.

7. The electronic device according to claim 1 , wherein the second portion comprises a plurality of sections extending transversely and crossing the first portion.

8. The electronic device according to claim 1 , wherein the resistor comprises first and second parallel coupled branches.

9. The electronic device according to claim 1 , further comprising a trimming circuit configured to generate a trimming current coupled to the second pair of contact regions.

10. The electronic device according to claim 9 , wherein the trimming circuit comprises a current source.

11. The electronic device according to claim 10 , wherein the trimming circuit further comprises a control stage coupled to and supplying control signals to the current source.

12. The electronic device according to claim 11 , wherein the trimming circuit further comprises a temperature sensor coupled to the control stage.

13. The electronic device according to claim 11 , wherein the trimming circuit further comprises a resistance gauge coupled to the control stage.

14. An electronic device comprising:
first and second pairs of contacts;
a trimming circuit; and
a resistor comprising a phase change material having an electrically modifiable resistivity responsive to the trimming circuit;
said resistor comprising first and second portions extending transversely and in direct electrical contact to each other at a crossing area, the first and the second portions being coplanar at least at the crossing area, at least one of the first and second portions having a varying width;
said first and second portions each having respective ends connected to respective ones of the first and second pairs of contacts.

15. The electronic device according to claim 14 , wherein the first and the second portions each comprises a Ge—Sb—Te alloy.

16. The electronic device according to claim 14 , wherein at least one of the first and second portions has a constant width.

17. The electronic device according to claim 14 , wherein the at least one of the first and second portions having the variable width includes a minimum width next to the crossing area.

18. The electronic device according to claim 14 , wherein the width of the first portion next to the crossing area is less than the width of the second portion next to the crossing area.

19. The electronic device according to claim 14 , wherein the second portion comprises a plurality of sections extending transversely and crossing the first portion.

20. The electronic device according to claim 14 , wherein the resistor comprises first and second parallel coupled branches.

21. The electronic device according to claim 14 , wherein the trimming circuit comprises a current source, and a control stage coupled to and supplying control signals to the current source.

22. The electronic device according to claim 21 , wherein the trimming circuit further comprises a temperature sensor coupled to the control stage.

23. The electronic device according to claim 21 , wherein the trimming circuit further comprises a resistance gauge coupled to the control stage.

24. A method for making an electronic device comprising:
forming first and second pairs of contacts; and
forming a resistor comprising a phase change material so as to have an electrically modifiable resistivity;
said resistor comprising first and second portions extending transversely and in direct electrical contact to each other at a crossing area, at least one of the first and second portions having a varying width;
said first and second portions each having respective ends connected to respective ones of the first and second pairs of contacts.

25. The method according to claim 24 , comprising forming the first and the second portions to be coplanar at least at the crossing area.

26. The method according to claim 24 , wherein the first and the second portions each comprises a Ge—Sb—Te alloy.

27. The method according to claim 24 , comprising forming at least one of the first and second portions to have a constant width.

28. The method according to claim 24 , comprising forming the at least one of the first and second portions with the variable width includes a minimum width next to the crossing area.

29. The method according to claim 24 , further comprising generating a trimming current coupled to the second pair of contact regions.

30. An electronic device comprising:
first and second pairs of contacts; and
a resistor comprising a phase change material so as to have an electrically modifiable resistivity;
said resistor comprising first and second portions extending transversely and in direct electrical contact to each other at a crossing area, the second portion comprising a plurality of sections extending transversely and crossing the first portion;
said first and second portions each having respective ends connected to respective ones of the first and second pairs of contacts.

31. An electronic device comprising:
first and second pairs of contacts; and
a resistor comprising a phase change material so as to have an electrically modifiable resistivity, and first and second parallel coupled branches;
said resistor comprising first and second portions extending transversely and in direct electrical contact to each other at a crossing area;
said first and second portions each having respective ends connected to respective ones of the first and second pairs of contacts.

32. An electronic device comprising:
first and second pairs of contacts;
a resistor comprising a phase change material so as to have an electrically modifiable resistivity;
said resistor comprising first and second portions extending transversely and in direct electrical contact to each other at a crossing area;
said first and second portions each having respective ends connected to respective ones of the first and second pairs of contacts; and
a trimming circuit configured to generate a trimming current coupled to the second pair of contact regions;
said trimming circuit comprising a

Assignees

• St Microelectronics Srl

Inventors

• Privitera Stefania Maria Serena
• Santangelo Antonello

Classifications

• H10P74/238

  comprising acting in response to an ongoing measurement without interruption of processing, e.g. endpoint detection or in-situ thickness measurement · CPC title

• H10P74/207

  Electrical properties, e.g. testing or measuring of resistance, deep levels or capacitance-voltage characteristics · CPC title

• H10P74/23

  characterised by multiple measurements, corrections, marking or sorting processes · CPC title

• H10D1/474

  comprising refractory metals, transition metals, noble metals, metal compounds or metal alloys, e.g. silicides · CPC title

• H01L45/06

  Electricity · mapped topic