Method for charge enhanced defect breakdown to improve yield and reliability
First Claim
1. A method of improving integrated circuit reliability, the method comprising the steps of:
- providing a layered wafer, the wafer comprising;
a substrate having a plurality of diffused regions;
at least one overlying conductive layer;
at least one overlying non-conductive layer, wherein the at least one non-conductive layer contains at least one embedded electrically-isolated conductive particle,and wherein the substrate, the plurality of diffused regions, and the at least one conductive layer are all electrically grounded; and
exposing the wafer to an electron beam of a pre-determined energy level for a pre-determined period of time, thereby increasing the electrical potential of the at least one embedded electrically-isolated conductive particle.
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Abstract
According to the present invention, an improved method for locating particle contamination during the integrated circuit manufacturing process is disclosed. The integrated circuit wafer is grounded and then exposed to an electron beam to create an enhanced electrical potential in any conducting or semi-conducting particles embedded in the layered wafer. The embedded particle will begin to accumulate an electrical charge and will reach a certain electrical potential based on the size and composition of the particle as well as the length of exposure to the electron beam. After a sufficient charge has been accumulated in the embedded particle, the wafer is subjected to burn-in testing. Since the particles embedded in the wafer have been previously exposed to the electron beam, the standard voltages applied during burn-in testing will force a certain number of embedded particles to suffer accelerated breakdown. After the defects have occurred and have been located, on-chip fuses can be used to re-route the circuits. As a final step, the wafer is annealed to remove any residual charge in any remaining particle defects not found by the present invention.
34 Citations
15 Claims
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1. A method of improving integrated circuit reliability, the method comprising the steps of:
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providing a layered wafer, the wafer comprising; a substrate having a plurality of diffused regions; at least one overlying conductive layer; at least one overlying non-conductive layer, wherein the at least one non-conductive layer contains at least one embedded electrically-isolated conductive particle, and wherein the substrate, the plurality of diffused regions, and the at least one conductive layer are all electrically grounded; and exposing the wafer to an electron beam of a pre-determined energy level for a pre-determined period of time, thereby increasing the electrical potential of the at least one embedded electrically-isolated conductive particle. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of improving integrated circuit reliability, the method comprising the steps of:
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providing a layered wafer, the wafer comprising; a substrate having a plurality of diffused regions; at least one overlying conductive layer; at least one overlying non-conductive layer, wherein the at least one non-conductive layer contains at least one embedded electrically-isolated conductive particle, and wherein the substrate, the purality of diffused regions, and the at least one condutive layer are all electrically grounded; exposing the wafer to an electron beam with an energy level of 25 keV for a period of six minutes, thereby increasing the electrical potential of the at least one embedded electrically-isolated conductive particle; performing burn-in testing on the wafer; and annealing the wafer to remove any excess electrical potential from the wafer. - View Dependent Claims (12, 13, 14)
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15. A method of improving integrated circuit reliability, the method comprising the steps of:
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providing a layered wafer, the wafer comprising; a substrate having a plurality of diffused regions; at least one overlying conductive layer; at least one overlying non-conductive layer, wherein the at least one non-conductive layer contains at least one embedded electrically-isolated conductive particle, and wherein the substrate, the purality of diffused regions, and the at least one condutive layer are all electrically grounded; exposing the wafer to an electron beam with an energy level of 25 keV for a period of six minutes, thereby increasing the electrical potential of the at least one embedded electrically-isolated particle; elevating the temperature of the wafer to enhance current dissipation; performing burn-in testing on the wafer; using a redundant circuit to bypass an inoperative circuit path; and annealing the wafer to remove any excess electrical potential from the wafer.
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Specification