Structure and method to measure focus-dependent pattern shift in integrated circuit imaging
AssigneeGlobalfoundries Inc.
InventorsLei Zhuang, Timothy A. Brunner
Life of this patent
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Abstract
Various embodiments include measurement structures and methods for measuring integrated circuit (IC) images. In some cases, a measurement structure for use in measuring an image of an IC, includes: a first section having a positive shift spacing pattern; a second section, on an opposite side of the measurement structure, having a negative shift spacing pattern; and a third section having a reference spacing pattern for calibrating a measurement from at least one of the first section or the second section.
Claims20
A measurement structure for use in calibrating image shift caused by a lithographic patterning process, the measurement structure comprising:
- a first section having a positive shift spacing pattern;
- a second section, on an opposite side of the measurement structure, having a negative shift spacing pattern;
- and
- a third section having a reference spacing pattern for calibrating a shift in a printed image of at least one of the first section or the second section of said measurement structure.
A method comprising:
- applying a measurement structure to a design of an integrated circuit (IC) device, the measurement structure including:
- a first section having a positive shift spacing pattern;
- a second section, on an opposite side of the measurement structure, having a negative shift spacing pattern;
- and
- a third section having a reference spacing pattern for calibrating shift in a printed image of the design of the IC relative to at least one of the first section or the second section of the measurement structure;
- printing the design of the IC device with the measurement structure on a wafer to form the printed image;
- and
- identifying a scaling factor to correct for the shift in the printed image of the design of the IC device.
The method of claim 18, wherein the relative shift is calculated according to the formula:
- Relative shift(RS)=(S1′−S2′)/2.
A measurement structure comprising:
- a first section having a positive shift spacing pattern;
- a second section, on an opposite side of the measurement structure, having a negative shift spacing pattern,
- wherein the positive shift spacing pattern includes a first set of spacing elements separated from one another by a first distance, and a second set of spacing elements separated from one another by a second distance distinct from the first distance;
- and
- a third section having a reference spacing pattern for calibrating shift in a printed image from at least one of the first section or the second section of the measurement structure, wherein the third section is located between the first section and the second section.
Dependencies are inferred from the claim text.