Method of making electric field emitter device for electrostatic discharge protection of integrated circuits
First Claim
1. A method of constructing an integrated circuit device for protecting circuits from electrostatic discharge, said method comprising the steps of:
- forming a first conductive trace over an insulating layer of a substrate of said integrated circuit device, said first conductive trace being connected to an input circuit path to be protected from said electrostatic discharge;
removing said insulating layer under a first end of said first conductive trace thereby leaving an undercut portion of said first conductive trace; and
forming a second conductive trace adjacent said undercut portion of said first conductive trace and said substrate wherein said second conductive trace is formed to leave a separation between said first conductive trace and said second conductive trace, said second conductive trace being connected to an electrostatic discharge path, wherein said electrostatic discharge path comprises a connection to either a circuit ground or a circuit supply voltage.
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Accused Products
Abstract
An electrostatic discharge device having a small separation between two traces wherein a voltage above a desired threshold will discharge across the separation through the mechanism of cold cathode electric field emission. Conditions which permit quantum mechanical tunneling of electrons across the emitting cathode/vacuum potential barrier, such as low emitter work function, electric field enhancing geometry, and cathode/anode separation size, determine the voltage necessary for discharge by this mechanism. One device has a first conductive trace formed on an insulating layer and then masked and etched to leave an undercut with a sharp point. A second conductive trace is formed in the undercut opposite the point, resulting in a three-dimensional cross section having a very small separation. A second device has the point formed by depositing a metal layer over a spacing in a dielectric layer, and then etching out the dielectric layer.
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Citations
2 Claims
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1. A method of constructing an integrated circuit device for protecting circuits from electrostatic discharge, said method comprising the steps of:
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forming a first conductive trace over an insulating layer of a substrate of said integrated circuit device, said first conductive trace being connected to an input circuit path to be protected from said electrostatic discharge; removing said insulating layer under a first end of said first conductive trace thereby leaving an undercut portion of said first conductive trace; and forming a second conductive trace adjacent said undercut portion of said first conductive trace and said substrate wherein said second conductive trace is formed to leave a separation between said first conductive trace and said second conductive trace, said second conductive trace being connected to an electrostatic discharge path, wherein said electrostatic discharge path comprises a connection to either a circuit ground or a circuit supply voltage. - View Dependent Claims (2)
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Specification