Buried short location determination using voltage contrast inspection
AssigneeInternational Business Machines Corporation
InventorsOliver D. Patterson, Horatio S. Wildman
Life of this patent
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Abstract
Structure and methods of determining the complete location of a buried short using voltage contrast inspection are disclosed. In one embodiment, a method includes providing a test structure having a PN junction thereunder; and using the PN junction to determine the location of the buried short using voltage contrast (VC) inspection. A test structure may include a plurality of test elements each having a PN junction thereunder, wherein a location of the buried short within the test structure can be determined using the PN junction and the VC inspection. The PN junction forces a change in illumination brightness of a test element including the buried short, thus allowing determination of the complete location of a buried short.
Claims5
A test structure for determining a location of a buried short using voltage contrast (VC) inspection, the test structure comprising:
- a plurality of test elements each having a structure allowing current flow in only one direction and only when forward biased, wherein the plurality of test elements each include a transistor including a first active region, a second active region and a gate electrode, wherein the structure includes one of a PN junction under each test element and an n-type field effect transistor having a source region and a gate electrode shorted together, and wherein in the case that the structure includes a PN junction, the PN junction is under the first active regions, which are connected by a shared sense line, and the second active regions are grounded by a shared ground line, and
- wherein a location of the buried short within the test structure can be determined using the structure and the VC inspection.
Dependencies are inferred from the claim text.