Evaluating a multi-layered structure for voids
AssigneeApplied Materials, Inc.
InventorsPeter Borden, Ji-Ping Li
Life of this patent
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Abstract
A method and apparatus measure properties of two layers of a damascene structure (e.g. a silicon wafer during fabrication), and use the two measurements to identify a location as having voids. The two measurements may be used in any manner, e.g. compared to one another, and voids are deemed to be present when the two measurements diverge from each other. In response to the detection of voids, a process parameter used in fabrication of the damascene structure may be changed, to reduce or eliminate voids in to-be-formed structures.
Claims19
A method for evaluating a structure that has a plurality of layers, the method comprising:
- measuring a first property of a first layer in the structure, to obtain a first measurement;
- measuring a second property of a second layer in the structure, to obtain a second measurement;
- and
- using the first measurement and the second measurement to determine existence of a void.
A method for evaluating a structure having at least a plurality of traces and a layer in contact with said traces, at least two traces in the plurality being each at least substantially parallel to the other, the method comprising:
- illuminating the structure with a first beam comprising electromagnetic radiation polarized parallel to the two traces;
- illuminating the structure with a second beam having intensity modulated at a predetermined frequency, the predetermined frequency being sufficiently small to ensure that heat generated in a region illuminated by the second beam transfers out of the region by diffusion;
- and
- measuring an attribute of said electromagnetic radiation reflected by at least said two traces and modulated at the predetermined frequency.
Dependencies are inferred from the claim text.