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US 12,640,338 B2Granted
Screening edge placement uniformity wafer stochastics
AssigneeKLA Corporation
InventorStefan Eyring
Life of this patent
Estimating the term…
Abstract
A simulated tool signal is determined from design data and tool properties of the tool making the measurements. A design-assisted composite signal is determined from measurements. An edge placement uniformity signal is then determined by comparing the simulated tool signal and the design-assisted composite signal. A shape and/or an area of the edge placement uniformity signal can be analyzed. The edge placement uniformity signal enables screening of structures with respect to wafer stochastics without the need to fully characterize all individual structures.
Claims18
A method comprising:
- determining, using a processor, a design-assisted composite signal from a plurality of features on a wafer using measurements of the wafer from a wafer metrology tool and a design of the wafer, wherein the design-assisted composite signal is a combination of the measurements;
- determining, using the processor, a simulated tool signal for the design of the wafer that accounts for noise sources and imaging properties of the wafer metrology tool;
- determining, using the processor, an edge placement uniformity signal that is a difference between the design-assisted composite signal and the simulated tool signal;
- and
- analyzing a shape and/or an area of the edge placement uniformity signal thereby determining placement of stochastics, wherein the shape and the area are caused by at least the stochastics.
2 more elements
A system comprising:
- a particle beam source that generates a particle beam;
- a stage configured to hold a wafer in a path of the particle beam;
- a detector that receives particles from the wafer;
- and
- a processor in electronic communication with the detector, wherein the processor is configured to:
- determine a design-assisted composite signal from a plurality of features on the wafer using measurements of the wafer and a design of the wafer, wherein the design-assisted composite signal is a combination of the measurements;
- determine a simulated tool signal for the design of the wafer that accounts for noise sources and imaging properties of the wafer metrology tool;
- determine an edge placement uniformity signal that is a difference between the design-assisted composite signal and the simulated tool signal;
- and
- analyze a shape and/or an area of the edge placement uniformity signal thereby determining placement of stochastics, wherein the shape and the area are caused by at least the stochastics.
7 more elements
Dependencies are inferred from the claim text.