IP Library › Granted Patent US 7,541,235
Granted Patent B2
US 7,541,235 · App. 11/447,585 · Granted Jun 2, 2009

Method for providing a programmable electrostatic discharge (ESD) protection device

Assignee: Micrel, Inc.
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Quick Facts
Patent No.
US 7,541,235
App. No.
11/447,585
Granted
Jun 2, 2009
Kind
B2
Abstract

A method for providing a programmable electrostatic discharge (ESD) protection device is provided. The method includes providing a source diffusion in a substrate, providing a deeper body diffusion in the substrate, providing a gate at a space between the source diffusion and the body diffusion, and providing a variable structure for shorting the source diffusion and the body diffusion to each other when ESD voltage is encountered on a circuit connected thereto, wherein the variable structure comprises a plurality of contacts over the source diffusion for the source diffusion to be grounded to the body diffusion.

Claims (18)

1. A method for providing a programmable electrostatic discharge (ESD) protection device, the method comprising:

providing a source diffusion in a substrate;

providing a deeper body diffusion than the source diffusion at its lowest point in the substrate;

providing a gate at a space between the source diffusion and the body diffusion; and

providing a variable structure for shorting the source diffusion and the body diffusion to each other when ESD voltage is encountered on a circuit connected thereto, wherein the variable structure comprises a plurality of contacts over the source diffusion for the source diffusion to be grounded to the body diffusion.

2. The method of claim 1 , wherein the variable structure causes the ESD protection device to operate in a snap back condition when the ESD voltage is encountered.

3. The method of claim 2 , wherein a snap back voltage of the ESD protection device is varied depending on which of the plurality of contacts is used to ground the source diffusion to the body diffusion.

4. The method of claim 2 , wherein the plurality of contacts allow for variable ESD voltage protection via snap back or sustaining voltage.

5. The method of claim 4 , wherein the ESD protection device can be utilized in high voltage and low voltage conditions.

6. The method of claim 5 , wherein resistance of the ESD protection device is an inverse function of the ESD voltage.

7. The method of claim 1 , wherein the gate is a metal gate.

8. The method of claim 1 , wherein the source diffusion comprises an N-type diffusion.

9. The method of claim 1 , wherein the deeper body diffusion comprises a P-type diffusion.

10. A method for providing a programmable electrostatic discharge (ESD) protection device, the method comprising:

providing a source diffusion in a substrate;

providing a deeper body diffusion than the source diffusion at its lowest point in the substrate;

providing a gate at a space between the source diffusion and the body diffusion; and

providing a variable structure for shorting the source diffusion and the body diffusion to each other when ESD voltage is encountered on a circuit connected thereto, wherein the variable structure comprises a plurality of contacts at variable distances over the source diffusion for the source diffusion to be grounded to the body diffusion, wherein a snap back voltage of the ESD protection device is varied depending a distance of a selected contact, from the plurality of contacts, used to ground the source diffusion to the body diffusion.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 23, 2007
From: HUSHER, JOHN DURBIN
To: MICREL, INC.
Reel/Frame 019196/0108 →
Continuity (2)
Division 1092770100 · Aug 27, 2004
Related Publication 20060237794A1 · Oct 26, 2006