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US 2006/0078808 A1Published application
Method for measuring overlay and overlay mark used therefor
AssigneeSamsung Electronics Co., Ltd.
InventorJeong-Hee Cho
Life of this patent
Estimating the term…
Abstract
An overlay measurement method and related apparatus are provided in which overlay measurement data is calculated on the basis of distances measured in disparate manners in relation to whether the current process is an initial process or a subsequent process. Related overlay marks are also described.
Claims18
An overlay measurement method, comprising:
- arranging a wafer on an exposure apparatus adapted to perform a process;
- identifying an overlay mark formed on the wafer;
- determining from the identified overlay mark whether or not the process is an initial process;
- and
- if the process is an initial process, calculating overlay measurement data using a first distance measurement, or if the process in not an initial process, calculating the overlay measurement data using a second distance measurement.
2 more elements
An overlay measurement method, comprising:
- arranging a wafer on an exposure apparatus adapted to perform a process;
- identifying an overlay mark formed on the wafer;
- determining from the identified overlay mark whether or not the process is an initial process;
- and
- if the process is an initial process, calculating overlay measurement data using a first distance measurement, wherein first distance measurement is made between a central position of the wafer and an overlay mark, or
- if the process in not an initial process, calculating the overlay measurement data using a second distance measurement, wherein the second distance measurement is made between one overlay mark formed on an existing layer and another overlay mark.
3 more elements
An overlay mark, comprising:
- a first overlay mark comprising a first inner mark and a first outer mark separately formed proximate an outer portion of a chip area on a wafer;
- and
- at least one second overlay mark comprising concentrically formed second inner mark and second outer mark having an identical center formed proximate an outer portion of the chip area.
Dependencies are inferred from the claim text.