Evaluation device and evaluation method
AssigneeNikon Corporation
InventorsKazuhiko Fukazawa, Yuji Kudo
Life of this patent
Estimating the term…
Abstract
In an evaluation device (1), an analyzer (42) is rotated so that the azimuth of the transmission axis of the analyzer (42) has an inclination angle of 90 degrees±3 degrees with respect to the transmission axis of a polarizer (32), an imaging camera (44) captures a regularly reflected image of a wafer (10) under each condition, and an image processing unit (50) evaluates the shape of a repeating pattern and detects dose defects and focus defects on the basis of the two images of the wafer (10) captured by the imaging camera (44).
Claims10
An evaluation device comprising:
- an illumination unit for radiating linearly polarized light to a surface of a substrate having a predetermined repeating pattern;
- an analyzer for extracting a polarization component having a different direction of vibration than the linearly polarized light from among regularly reflected light from the repeating pattern irradiated by the linearly polarized light;
- an imaging unit for capturing a regularly reflected image of the substrate based on the polarization component extracted by the analyzer;
- a setting unit for setting an angle condition between the direction of vibration of the linearly polarized light and the direction of vibration of the polarization component, or between the direction of vibration of the linearly polarized light and the direction of repetition of the repeating pattern;
- and
- an evaluation unit for evaluating a state of the repeating pattern on the basis of an image of the regularly reflected image captured by the imaging unit;
- the imaging unit being configured so as to capture the regularly reflected image obtained in a plurality of angle conditions between the direction of vibration of the linearly polarized light and the direction of vibration of the polarization component, or a plurality of angle conditions between the direction of vibration of the linearly polarized light and the direction of repetition of the repeating pattern, the angle conditions being set by the setting unit;
- and
- the evaluation unit being configured so as to evaluate a state of the repeating pattern on the basis of images of the plurality of regularly reflected images captured by the imaging unit.
An evaluation method for radiating linearly polarized light to a surface of a substrate having a predetermined repeating pattern, extracting a polarization component having a different direction of vibration than the linearly polarized light from among regularly reflected light from the repeating pattern irradiated by the linearly polarized light, capturing a regularly reflected image of the substrate based on the extracted polarization component, and evaluating a state of the repeating pattern;
- the evaluation method comprising the steps of:
- a first step for setting an angle condition between the direction of vibration of the linearly polarized light and the direction of vibration of the polarization component, or between the direction of vibration of the linearly polarized light and the direction of repetition of the repeating pattern;
- a second step for radiating the linearly polarized light to a surface of the substrate in a plurality of angle conditions between the direction of vibration of the linearly polarized light and the direction of vibration of the polarization component, or a plurality of angle conditions between the direction of vibration of the linearly polarized light and the direction of repetition of the repeating pattern, the angle conditions being set in the first step;
- a third step for extracting a polarization component in the plurality of angle conditions having a different direction of vibration than the linearly polarized light from among regularly reflected light from the repeating pattern irradiated by the linearly polarized light;
- a fourth step for capturing a regularly reflected image of the substrate based on the polarization component extracted in the third step, in the plurality of angle conditions;
- and
- a fifth step for evaluating a state of the repeating pattern on the basis of images of the plurality of regularly reflected images captured in the fourth step in the plurality of angle conditions.
Dependencies are inferred from the claim text.