Floating gate structure with high electrostatic discharge performance

• US 20070236843A1
• Filed: 01/18/2007
• Published: 10/11/2007
• Est. Priority Date: 07/26/2005
• Status: Active Grant

• Current Assignee: Vishay Siliconix
• Original Assignee: Vishay Siliconix
• Inventors: Luo, Min-Yih, Demirlioglu, Esin
• Granted Patent: US 9,111,754 B2
• Time in Patent Office: Days
• US Class Current: 361/56
• CPC Class Codes: H01L 27/027 specially adapted to provide an electrical current path other than the field effect induced current path
• CPC Class Codes: H01L 29/0626 with a localised breakdown region, e.g. built-in avalanching region in self-protected thyristors H01L29/7424
• CPC Class Codes: H01L 29/861 Diodes
• 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

Systems and methods for floating gate structures with high electrostatic discharge performance. In one embodiment, a semiconductor structure includes a floating field gate device. The floating field gate device includes an embedded diode characterized as having less temperature dependence than a Zener diode. The breakdown voltage of the embedded diode is greater than an operating voltage of an associated integrated circuit and a snapback trigger voltage of the embedded diode is lower than a breakdown voltage of the semiconductor structure.

Claims

1. A semiconductor structure comprising:

a floating field gate device; and

wherein said floating field gate device comprises an embedded diode characterized as having less temperature dependence than a Zener diode.

2. A semiconductor structure of claim 1 wherein said embedded diode comprises a p/n type diode.

3. A semiconductor structure of claim 2 wherein said embedded diode further comprises a Zener diode.

4. A semiconductor structure of claim 3 wherein said p/n type diode and said Zener diode comprise a common cathode.

5. A semiconductor structure of claim 4 wherein a snapback holding voltage of said embedded diode is greater than an operating voltage of an associated integrated circuit and a snapback trigger voltage of said embedded diode is lower than a breakdown voltage of said semiconductor structure.

6. A semiconductor structure of claim 5 operable to be triggered by an ESD trigger voltage wherein a portion of an ESD holding voltage is sustained by said embedded diode when said embedded diode is conducting.

7. A semiconductor structure of claim 6 wherein said embedded diode is off after an electrostatic discharge (ESD) event.

8. A semiconductor structure for electrostatic discharge protection comprising:

a plurality of first fingers coupled to an output pad;

a plurality of second fingers interlaced between said first fingers and coupled to a ground pad;

a plurality of floating field gates interposed between said first and second fingers; and

wherein said first fingers comprise an embedded hybrid diode characterized as having a diode breakdown voltage lower than a breakdown voltage of said semiconductor structure and a snapback trigger voltage less than said breakdown voltage of said semiconductor structure.

9. A semiconductor structure of claim 8 wherein said embedded hybrid diode is characterized as having less temperature dependence than a Zener diode.

10. A semiconductor structure of claim 8 wherein said embedded hybrid diode is characterized as having less temperature dependence than a p/n diode.

11. A semiconductor structure of claim 8 wherein said embedded hybrid diode comprises a Zener diode.

12. A semiconductor structure of claim 8 wherein said embedded hybrid diode comprises a p/n diode.

13. A semiconductor structure of claim 12 wherein said p/n diode comprises a well of anode material.

14. A semiconductor structure of claim 8 wherein said embedded hybrid diode comprises a Zener diode and a p/n diode, both sharing a common cathode.

15. A semiconductor structure of claim 8 wherein said ESD structure accommodates adjustments to its breakdown voltage.

16. A semiconductor structure comprising:

a circuit for driving an off-chip output;

wherein said circuit comprises a pull-down device; and

a hybrid diode device embedded in said circuit characterized as having a trigger voltage below a breakdown voltage of said pull-down device.

17. An electrostatic discharge (ESD) protection circuit for an integrated circuit (IC) for providing protection during an ESD event, said circuit comprising:

a current flow control component; and

a current flow direction control component coupled in series to said current flow control component,

wherein a snapback holding voltage of said electrostatic discharge protection circuit is greater than an operating voltage of the integrated circuit and a snapback trigger voltage of said electrostatic discharge protection circuit is lower than an oxide breakdown voltage of said IC.

18. The ESD protection circuit of claim 17 wherein said current flow control component is a transistor.

19. The ESD protection circuit of claim 17 wherein said transistor is a MOSFET.

20. The ESD protection circuit of claim 18 wherein said transistor and said diode are shut off after an ESD event.

21. The ESD protection circuit of claim 17 wherein said current flow direction control component is a diode embedded into said current flow control component.

22. The ESD protection circuit of claim 21 operable to be triggered by an ESD trigger voltage wherein a portion of a holding voltage is sustained by said diode when said diode is conducting.