Heater design for heat-trimmed thin film resistors

• US 8,786,396 B2
• Filed: 12/29/2011
• Issued: 07/22/2014
• Est. Priority Date: 09/17/2008
• Status: Active Grant

• Current Assignee: STMicroelectronics International N.V. (STMicroelectronics NV)
• Original Assignee: Stmicroelectronics Pte Limited (STMicroelectronics NV)
• Inventors: Leung, Calvin, Le Neel, Olivier
• Primary Examiner(s): LEE, KYUNG S
• Application Number:
  US13/339,968
• Publication Number:
  US 20120119872A1
• Time in Patent Office: 936 Days
• Field of Search: 338/22.R, 338/22.SD, 338/25
• US Class Current: 338/25
• CPC Class Codes: H01C 17/265 by chemical or thermal treatment, e.g. oxydation, reduction, annealing etching H01C17/2416
• CPC Class Codes: H01C 17/267 by passage of voltage pulses or electric current
• CPC Class Codes: H01L 23/345 Arrangements for heating thermal treatment apparatus H01L21/00
• CPC Class Codes: H01L 23/5228 Resistive arrangements or effects of, or between, wiring layers other resistive arrangements H01L23/647
• CPC Class Codes: H01L 24/05 of an individual bonding area
• CPC Class Codes: H01L 27/016 Thin-film circuits
• CPC Class Codes: H01L 27/0688 Integrated circuits having a three-dimensional layout
• CPC Class Codes: H01L 28/20 Resistors
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/01019 Potassium [K]
• CPC Class Codes: H01L 2924/1301 Thyristor
• CPC Class Codes: H01L 2924/13033 TRIAC - Triode for Alternating Current - A bidirectional switching device containing two thyristor structures with common gate contact
• CPC Class Codes: H01L 2924/1305 Bipolar Junction Transistor [BJT]
• CPC Class Codes: H01L 2924/13091 Metal-Oxide-Semiconductor Field-Effect Transistor [MOSFET]
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/1461 MEMS

Abstract

A heater design for post-process trimming of thin-film transistors is described. The heater incorporates low sheet-resistance material deposited in non-active connecting regions of the heater to reduce heat generation and power consumption in areas distant from active heating members of the heater. The heating members are proximal to a thin-film resistor. The resistance of the thin-film resistor can be trimmed permanently to a desired value by applying short current pulses to the heater. Optimization of a heater design is described. Trimming currents can be as low as 20 mA.

Claims

1. A heat-trimmable resistor comprising:

a thin-film resistive element configured as a resistor that is connected to or connectable to a circuit;

a thin-film heating region proximal at least a portion of the thin-film resistive element; and

an electrically-conductive material in electrical contact with the thin-film heating region and having lower sheet resistance than the thin-film heating region that connects the thin-film heating region to a conductive interconnect.

2. The heat-trimmable resistor of claim 1 incorporated in an integrated circuit.

3. The heat-trimmable resistor of claim 1, wherein the thickness of the electrically-conductive material is greater than the thickness of the thin-film heating region.

4. The heat-trimmable resistor of claim 3, wherein the thickness of the electrically-conductive material is greater than about 10 nm.

5. The heat-trimmable resistor of claim 3, wherein the thickness of the electrically-conductive material is greater than about 50 nm.

6. The heat-trimmable resistor of claim 1, wherein the electrically-conductive material comprises aluminum.

7. The heat-trimmable resistor of claim 6, wherein the electrically-conductive material further comprises copper.

8. The heat-trimmable resistor of claim 1, wherein an active area heating efficiency of the heat-trimmable resistor is greater than about 350°

C./W.

9. The heat-trimmable resistor of claim 1, wherein the thin-film resistive element is patterned to have one or a plurality of elongated legs and the thin-film heating region is separated from the one or a plurality of elongated legs by at least one thermally-conductive material.

10. The heat-trimmable resistor of claim 9, wherein the plurality of legs are substantially parallel.

11. The heat-trimmable resistor of claim 9, wherein the plurality of legs are configured in a serpentine pattern.

12. The heat-trimmable resistor of claim 9, wherein the one or plurality of legs each have a length between about 10 microns and about 300 microns.

13. The heat-trimmable resistor of claim 9, wherein the one or plurality of legs each have a width between about 250 nm and about 10 microns.

14. The heat-trimmable resistor of claim 9, wherein the electrically-conductive material is deposited proximal to at least one end portion of the one or plurality of elongated legs.

15. The heat-trimmable resistor of claim 14, wherein the deposited electrically-conductive material is deposited to connect to at least one end portion of the thin-film heating region.

16. The heat-trimmable resistor of claim 14, wherein the electrically-conductive material further electrically connects with an underlying first electrical conductor.

17. The heat-trimmable resistor of claim 16, wherein the connection with the first electrical conductor is formed through at least one via.

18. The heat-trimmable resistor of claim 16, wherein the thin-film resistive element electrically connects with a second electrical conductor.

19. The heat-trimmable resistor of claim 18, wherein the first electrical conductor and second electrical conductor are deposited at the same time.