Test device and method for signalling metal failure of semiconductor wafer
First Claim
1. A test device for signalling possible metal failure of a semiconductor wafer, said test device comprising:
- a metal monitor structure prone to metal failure;
a metal control structure resistant to metal failure such that said metal control structure is less prone to metal failure than said metal monitor structure; and
wherein said metal monitor structure and said metal control structure have substantially identical resistances without metal failure of said metal monitor structure and a resistance difference upon metal failure of said metal monitor structure, said resistance difference signalling possible metal failure of said semiconductor wafer.
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Accused Products
Abstract
Method and test structures for accurately flagging metal failure on a semiconductor wafer include a monitor structure and a control structure, each of which has a plurality of metal segments. At least one metal segment of the monitor structure has a length prone to failure, while the length of the metal segments in the control structure are such that the control structure is resistant to metal failure. The monitor and control structures are predesigned to have equal resistance when there is no metal failure and a measurable resistance difference upon metal failure in that segment of the monitor structure prone to failure. Upon detecting metal failure in the test device, the wafer is flagged as potentially having metal failure in active circuitry interconnect wiring.
94 Citations
37 Claims
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1. A test device for signalling possible metal failure of a semiconductor wafer, said test device comprising:
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a metal monitor structure prone to metal failure; a metal control structure resistant to metal failure such that said metal control structure is less prone to metal failure than said metal monitor structure; and wherein said metal monitor structure and said metal control structure have substantially identical resistances without metal failure of said metal monitor structure and a resistance difference upon metal failure of said metal monitor structure, said resistance difference signalling possible metal failure of said semiconductor wafer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A test device for signalling possible metal failure of a semiconductor wafer, said test device comprising:
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a monitor structure having a first plurality of metal segments electrically connected together, at least one metal segment of said first plurality of metal segments being prone to metal failure; a control structure having a second plurality of metal segments electrically connected together such that no metal segment of said second plurality of metal segments is prone to metal failure and such that said control structure is less prone to metal failure than said metal monitor structure; and wherein said monitor structure and said control structure have substantially identical resistances without metal failure of said at least one metal segment prone to metal failure, and a resistance difference upon metal failure of said at least one metal segment prone to metal failure, said resistance difference signalling possible metal failure of said semiconductor wafer. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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29. A metal test structure for indicating possible metal failure of a semiconductor wafer, said metal test structure comprising:
a plurality of test devices disposed in an inactive region of said semiconductor wafer, each test device of said plurality of test devices comprising; a metal monitor structure prone to metal failure; a metal control structure resistant to metal failure such that said metal control structure is less prone to metal failure than said metal monitor structure; and wherein said metal monitor structure and said metal control structure have substantially identical resistances without metal failure of said metal monitor structure and a resistance difference upon metal failure of said metal monitor structure, said resistance difference signalling possible metal failure of said semiconductor wafer. - View Dependent Claims (30, 31, 32, 33)
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34. A method for fabricating a test device for indicating possible metal failure of a semiconductor wafer, said method comprising the steps of:
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(a) predesigning a metal monitor structure and a metal control structure such that said metal monitor structure is prone to metal failure and said metal control structure is resistant to metal failure, such that said metal control structure is less prone to metal failure than said metal monitor structure, and such that said metal monitor structure and said metal control structure have substantially identical resistances without metal failure of said metal monitor structure and a resistance difference upon metal failure of said metal monitor structure, said resistance difference indicating possible metal failure of said semiconductor wafer; and (b) fabricating said metal monitor structure and said metal control structure at an inactive region of said semiconductor wafer. - View Dependent Claims (35, 36, 37)
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Specification