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US 12,723,873 B2Granted
Overlay measuring method and system, and method of manufacturing a semiconductor device using the same
AssigneeSamsung Electronics Co., Ltd.
InventorsInho Kwak, Jinsun Kim, Moosong Lee, Seungyoon Lee, Jeongjin Lee, Chan Hwang, Dohyeon Park, Yeeun Han
Life of this patent
Estimating the term…
Abstract
In an overlay measurement method, an overlay mark having programmed overlay values is provided. The overlay mark is scanned with an electron beam to obtain a voltage contrast image. A defect function that changes according to the overlay value is obtained from voltage contrast image data. Self-cross correlation is performed on the defect function to determine an overlay.
Claims20
An overlay measurement method, comprising:
- providing an overlay mark having designed overlay values;
- scanning the overlay mark with an electron beam to obtain a voltage contrast image;
- obtaining a defect function from voltage contrast image data of the voltage contrast image, the defect function changing according to the designed overlay values;
- and
- performing self-cross correlation on the defect function to determine an overlay.
2 more elements
An overlay measurement method, comprising:
- scanning at least one overlay mark with an electron beam, the at least overlay mark including upper structures misaligned with respect to lower structures so as to have designed overlay values;
- detecting secondary electrons emitted from the overlay mark to obtain voltage contrast data;
- obtaining a defect function from the voltage contrast data of voltage contrast for overlay;
- obtaining a function that is symmetric about overlay axis of the defect function;
- and
- performing cross correlation between the defect function and the symmetric function to calculate an overlay value.
3 more elements
Dependencies are inferred from the claim text.