Detecting breakdown in dielectric layers
AssigneeLucent Technologies Inc.
InventorsGlenn Baldwin Alers, Kathleen Susan Krisch, Bonnie Elaine Weir
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Abstract
The breakdown of an ultra-thin dielectric layer is detected by applying a test signal to the layer. Measurements are taken of noise signals present in the layer during the application of the test signal. At breakdown, a significant increase occurs in the amplitude of the measured noise signals.
Claims19
Apparatus for detecting the occurrence of electrical breakdown in a fixed-thickness dielectric layer, said apparatus comprising
- means for applying a test signal to said fixed-thickness layer,
- and means for detecting when the amplitude of noise signals in said layer during the application thereto of said test signal exceeds a prespecified value, thereby to indicate the occurrence of electrical breakdown in said fixed-thickness dielectric layer.
A method of detecting the occurrence of electrical breakdown in a fixed-thickness dielectric layer, said method comprising the steps of
- applying a test signal to said fixed-thickness layer,
- and detecting when the amplitude of the noise signal in said layer during the application of said test signal thereto increases beyond a prespecified value, thereby to indicate the occurrence of electrical breakdown in said fixed-thickness layer.
A method of testing a wafer that includes at least one test structure that contains a fixed-thickness dielectric layer, said method comprising the steps of
- applying a momentary test signal to said test structure,
- measuring the amplitude of the resulting noise signal generated in said test structure,
- and rejecting devices on said wafer if the noise signal exceeds a prespecified value which indicates that the fixed-thickness dielectric layer in said test structure has broken down.
Dependencies are inferred from the claim text.