Integrated circuit device for driving a laser diode with reduced heat transfer and method for fabricating the device

• US 7,129,640 B2
• Filed: 06/03/2003
• Issued: 10/31/2006
• Est. Priority Date: 06/03/2003
• Status: Expired due to Fees

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies Fiber IP Singapore PTE Limited (Broadcom, Inc.)
• Inventors: Flower, Graham McRae
• Primary Examiner(s): Phan, Tho
• Assistant Examiner(s): Tran, Chuc
• Application Number:
  US10/454,172
• Publication Number:
  US 20040245936A1
• Time in Patent Office: 1,246 Days
• Field of Search: 136/204, 136/201, 136/205, 136/203, 136/200, 136/225, 62/33, 62/32, 315/169.3, 315/169.1, 315312-313, 315/120, 438/122, 361/719, 361/735, 361/784, 257/724, 257712-717, 257/675, 257/720, 257/796, 257/787
• US Class Current: 315/120
• CPC Class Codes: H01L 23/3677 Wire-like or pin-like cooling fins or heat sinks
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

An integrated circuit (IC) device for driving a light emitting device, such as a laser diode, includes a heat-absorbing structure fabricated on a substrate over an electrical component, such as an output transistor, to reduce the heat transfer between the electrical component and the light emitting device. The heat-absorbing structure is designed to absorb some of the heat generated by the electrical component so that less heat from the electrical component is transferred to the light emitting device, which reduces the operating temperature of the light emitting device. A method of fabricating the IC device includes forming the electrical component on the substrate and forming the heat-absorbing structure on the substrate over the electrical component. The heat-absorbing structure may be configured to substantially encase the electrical component.

Claims

1. An integrated circuit device comprising:

a semiconductor substrate;

an electrical component formed on said semiconductor substrate, said electrical component being configured to generate heat during operation; and

a thermally conductive structure formed on said semiconductor substrate over said electrical component, said thermally conductive structure being designed to absorb some of said heat generated by said electrical component to reduce heat transfer from the electrical component, wherein said electrical component is an output transistor of the circuit fabricated on the substrate.

2. The integrated circuit device of claim 1 wherein said thermally conductive structure is configured to substantially encase said electrical component.

3. The integrated circuit device of claim 2 wherein said thermally conductive structure is made of a metallic material.

4. The integrated circuit device of claim 3 wherein said thermally conductive structure includes multi-level patterned metal layers that are interconnected by plugs.

5. The integrated circuit device of claim 4 wherein at least one of said multi-level patterned metal layers includes a break for an interconnect to traverse through said thermally conductive structure to connect with said electrical component.

6. The integrated circuit device of claim 2 wherein said thermally conductive structure is shaped in a box-like configuration.

7. The integrated circuit device of claim 1 further comprising trenches formed in said semiconductor substrate next to said thermally conductive structure, said trenches being filled with a thermally insulating material.

8. The integrated circuit device of claim 7 wherein said thermally insulating material includes oxide.

9. An integrated circuit device for driving an external device comprising:

a silicon substrate;

an output transistor formed on said silicon substrate, said output transistor being designed to provide driving signals to said external device, said output transistor being configured to generate heat during operation; and

a thermally conductive structure formed on said silicon substrate over said output transistor, said thermally conductive structure being designed to absorb some of said heat generated by said output transistor to reduce heat transfer from said output transistor.

10. The integrated circuit device of claim 9 wherein said thermally conductive structure is configured to substantially encase said output transistor.

11. The integrated circuit device of claim 10 wherein said thermally conductive structure is made of a metallic material.

12. The integrated circuit device of claim 11 wherein said thermally conductive structure includes multi-level patterned metal layers that are interconnected by plugs.

13. The integrated circuit device of claim 12 wherein at least one of said multi-level patterned metal layers includes a break for an interconnect to traverse through said thermally conductive structure to connect with said output transistor.

14. The integrated circuit device of claim 9 further comprising trenches formed in said silicon substrate next to said thermally conductive structure, said trenches being filled with a thermally insulating material.

15. The integrated circuit device of claim 14 wherein said thermally insulating material includes oxide.

16. A method for fabricating an integrated circuit device comprising:

providing a semiconductor substrate;

forming an electrical component on said semiconductor substrate; and

forming a thermally conductive structure on said semiconductor substrate over said electrical component, wherein said forming of said electrical component includes forming an output transistor of the circuit on said substrate said thermally conductive structure allowing heat generated by said electrical component to be absorbed to reduce heat transfer from said electrical component.

17. The method of claim 16 wherein said forming of said thermally conductive structure includes substantially encasing said electrical component with said thermally conductive structure.

18. The method of claim 17 wherein said forming of said thermally conductive structure includes constructing multi-level patterned metal layers that are interconnected by plugs.

19. The method of claim 18 wherein said constructing of said multi-level patterned metal layer includes creating a break in one of said multi-level pattered metal layer, said break being used for an interconnect to traverse through said thermally conductive structure to connect with said electrical component.

20. The method of claim 16 further comprising forming trenches in said semiconductor substrate next to said thermally conductive structure, including filling said trenches with a thermally insulating material.

21. The method of claim 20 wherein said filling of said trenches includes filling said trenches with oxide.