Methods of controlling distortion of exposure processes
First Claim
1. A method of controlling distortion of an exposure, the method comprising:
- aligning an exposure mask with a wafer, wherein the exposure mask includes at least one first image pattern, at least one overlay image outer mark, at least one second image pattern having a feature different from the first image pattern, and at least one overlay image inner mark;
forming a first test pattern on the wafer using a first exposure with the exposure mask and a first illumination system;
forming a photoresist layer on an entire surface of the wafer including the first test pattern;
performing a second exposure with the exposure mask and a second illumination system different from the first illumination system to form a second test pattern overlapping with the first test pattern, wherein the second image pattern and the overlay image inner mark of the exposure mask are transferred to the photoresist layer to overlap with the first test pattern during the second exposure;
extracting a distortion value between the first test pattern and the second test pattern; and
correcting the exposure mask or fabricating a corrected exposure mask using the distortion value.
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Abstract
A method of controlling distortion of an exposure process is provided. The method includes aligning an exposure mask with a wafer, forming a first test pattern on the wafer by performing a first exposure with the exposure mask and a first illumination system, forming a photoresist layer on an entire surface of the wafer including the first test pattern, performing a second exposure with the exposure mask and a second illumination system to form a second test pattern overlapping with the first test pattern, extracting a distortion value between the first test pattern and the second test pattern, and correcting the exposure mask or fabricating a corrected exposure mask using the distortion value.
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Citations
20 Claims
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1. A method of controlling distortion of an exposure, the method comprising:
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aligning an exposure mask with a wafer, wherein the exposure mask includes at least one first image pattern, at least one overlay image outer mark, at least one second image pattern having a feature different from the first image pattern, and at least one overlay image inner mark; forming a first test pattern on the wafer using a first exposure with the exposure mask and a first illumination system; forming a photoresist layer on an entire surface of the wafer including the first test pattern; performing a second exposure with the exposure mask and a second illumination system different from the first illumination system to form a second test pattern overlapping with the first test pattern, wherein the second image pattern and the overlay image inner mark of the exposure mask are transferred to the photoresist layer to overlap with the first test pattern during the second exposure; extracting a distortion value between the first test pattern and the second test pattern; and correcting the exposure mask or fabricating a corrected exposure mask using the distortion value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification